THE TRUSTEES OF PURDUE UNIVERSITY v. WOLFSPEED, INC.

IN THE UNITED STATES DISTRICT COURT

FOR THE MIDDLE DISTRICT OF NORTH CAROLINA

THE TRUSTEES OF PURDUE )

UNIVERSITY, )

)

Plaintiff, )

)

v. ) 1:21-cv-840

)

WOLFSPEED, INC., )

)

Defendant. )

CLAIM CONSTRUCTION MEMORANDUM OPINION AND ORDER

OSTEEN, JR., District Judge

This matter is before this court for claim construction of

terms in U.S. Patent No. 7,498,633 (“the ‘633 Patent”). The

parties — Plaintiff, the Trustees of Purdue University, and

Defendant Wolfspeed, Inc. — do not dispute the construction of

several previously-disputed claim terms, so those terms no longer

require construction. (Joint Notice Regarding Dropped Claim Terms

(Doc. 124) at 1.) The parties disagree as to the construction of

four claim terms in Claims 9 and 10 of the ‘633 Patent, and they

have submitted proposed constructions of those terms. (Ex. A

(“Claim Construction Summary”) (Doc. 85-1) at 1–12.) Both parties

have submitted opening claim construction briefs, (Doc. 103

(Plaintiff); Doc. 104 (Defendant)), as well as responsive briefs,

(Doc. 117 (Plaintiff); Doc. 118 (Defendant)). This court held a

claim construction hearing on May 5, 2023, at which time this

court took this matter under advisement. (Minute Entry

05/05/2023.) For the reasons set forth herein, this court

concludes as follows:

Plaintiff’s Defendant’s Court’s

Claim Term

Construction Construction Construction

“a first source No construction Claim 9’s use No construction

electrode necessary of the necessary

formed over the terms “first”

first source and “second”

region” / “a requires

second source distinct

electrode elements (i.e.,

formed over the the “first

second source source

region” (Claim electrode” must

9) be distinct

from the

“second

source

electrode”)

“a JFET region No construction Indefinite No construction

defined between necessary necessary

the first

source region

and the second

source region”

(Claim 9)

“the JFET No construction Indefinite No construction

region having a necessary necessary,

width less than subject to

about three supplemental

micrometers” briefing

(Claim 9)

“the JFET No construction Indefinite No construction

region having a necessary necessary,

width of about subject to

one micrometer” supplemental

(Claim 10, briefing

depends from

Claim 9)

I. LEGAL STANDARD

In Markman v. Westview Instruments, Inc., 517 U.S. 370

(1996), the Supreme Court clarified which issues in a patent

trial are properly reserved for the jury and which are questions

of law to be determined by the court. Specifically, the Court

held that interpretation of language in patent claims “is an

issue for the judge, not the jury[.]” Id. at 391. The Federal

Circuit has provided further guidance on how to interpret patent

claims, stating that, in general, courts are to give the words of

a claim “their ordinary and customary meaning” as understood by

“a person of ordinary skill in the art in question at the time of

the invention[.]” Phillips v. AWH Corp., 415 F.3d 1303, 1312–13

(Fed. Cir. 2005) (en banc) (citations omitted).

In construing claim terms, courts are directed to consult

several specific types of evidence to discern what a person of

ordinary skill in the art would understand the term to mean.

Because the meaning of a claim term as understood by

persons of skill in the art is often not immediately

apparent, and because patentees frequently use terms

idiosyncratically, the court looks to “those sources

available to the public that show what a person of

skill in the art would have understood disputed claim

language to mean.” Those sources include “the words of

the claims themselves, the remainder of the

specification, the prosecution history, and extrinsic

evidence concerning relevant scientific principles, the

meaning of technical terms, and the state of the art.”

Id. at 1314 (citations omitted).

First, “the claims themselves provide substantial guidance

as to the meaning of particular claim terms.” Id. (citation

omitted). “To begin with, the context in which a term is used in

the asserted claim can be highly instructive.” Id. Federal

Circuit case law “provide[s] numerous . . . examples in which the

use of a term within the claim provides a firm basis for

construing the term.” Id. (citations omitted).

Other claims of the patent in question, both

asserted and unasserted, can also be valuable sources

of enlightenment as to the meaning of a claim term.

Because claim terms are normally used consistently

throughout the patent, the usage of a term in one claim

can often illuminate the meaning of the same term in

other claims. Differences among claims can also be a

useful guide in understanding the meaning of particular

claim terms. For example, the presence of a dependent

claim that adds a particular limitation gives rise to a

presumption that the limitation in question is not

present in the independent claim.

Id. at 1314-15 (citations omitted). “The words of a claim are

generally given their ordinary and customary meaning as

understood by a person of ordinary skill in the art when read in

the context of the specification and prosecution history.”

Thorner v. Sony Comput. Entm’t Am. LLC, 669 F.3d 1362, 1365 (Fed.

Cir. 2012) (citation omitted).

The second type of evidence the court should consider is the

specification, which “contains a written description of the

invention that must enable one of ordinary skill in the art to

make and use the invention.” See Markman v. Westview Instruments,

Inc., 52 F.3d 967, 979 (Fed. Cir. 1995) (en banc), aff’d, 517

U.S. 370 (1996); see also Phillips, 415 F.3d at 1315. “Claims

must be read in view of the specification, of which they are a

part.” Markman, 52 F.3d at 979 (citations omitted). The claims

define the invention, but “the specification ‘is always highly

relevant to the claim construction analysis. Usually, it is

dispositive; it is the single best guide to the meaning of a

disputed term.’” Phillips, 415 F.3d at 1315 (citation omitted).

“For claim construction purposes, the description may act as a

sort of dictionary, which explains the invention and may define

terms used in the claims.” Markman, 52 F.3d at 979 (citation

omitted). “[A] patentee is free to be his own

lexicographer[, but] . . . any special definition given to a word

must be clearly defined in the specification.” Id. at 980

(citations omitted). “[C]laims are not to be interpreted by

adding limitations appearing only in the specification. . . .

[P]articular embodiments appearing in a specification will not be

read into the claims when the claim language is broader than such

embodiments.” Electro Med. Sys., S.A. v. Cooper Life Scis., Inc.,

34 F.3d 1048, 1054 (Fed. Cir. 1994) (citations omitted). A

limitation from the specification should only be read into the

claims when the specification requires that limitation. See id.

The third type of evidence that a court should consider is

the patent’s prosecution history. See Phillips, 415 F.3d at 1317;

see also Markman, 52 F.3d at 980; Vitronics Corp. v.

Conceptronic, Inc., 90 F.3d 1576, 1582 (Fed. Cir. 1996). “This

‘undisputed public record’ of proceedings in the Patent and

Trademark Office is of primary significance in understanding the

claims.” Markman, 52 F.3d at 980 (citation omitted). “The

prosecution history limits the interpretation of claim terms so

as to exclude any interpretation that was disclaimed during

prosecution. Claims may not be construed one way in order to

obtain their allowance and in a different way against accused

infringers.” Southwall Techs., Inc. v. Cardinal IG Co., 54 F.3d

1570, 1576 (Fed. Cir. 1995) (citations omitted).

There are two relevant exceptions to the general rule that

claim terms “are generally given their ordinary and customary

meaning as understood by a person of ordinary skill in the

art[.]” Thorner, 669 F.3d at 1365 (citation omitted).

First, the claim term will not receive its ordinary

meaning if the patentee acted as his own lexicographer

and clearly set forth a definition of the disputed

claim term in either the specification or prosecution

history. Second, a claim term will not carry its

ordinary meaning if the intrinsic evidence shows that

the patentee distinguished that term from prior art on

the basis of a particular embodiment, expressly

disclaimed subject matter, or described a particular

embodiment as important to the invention.

CCS Fitness, Inc. v. Brunswick Corp., 288 F.3d 1359, 1366–67

(Fed. Cir. 2002) (citations omitted); see also Thorner, 669 F.3d

at 1365.

The redefinition of a claim term away from its ordinary

meaning must be clear “so as to put one reasonably skilled in the

art on notice that the patentee intended to so redefine the claim

term.” Bell Atl. Network Servs., Inc. v. Covad Commc’ns Grp.,

Inc., 262 F.3d 1258, 1268 (Fed. Cir. 2001) (citations omitted).

However, redefinition need not be explicit. Id. “[T]he

specification may define claim terms ‘by implication’ such that

the meaning may be ‘found in or ascertained by a reading of the

patent documents.’” Id. (citation omitted); see also Trs. of

Columbia Univ. v. Symantec Corp., 811 F.3d 1359, 1364 (Fed. Cir.

2016).

“The party seeking to invoke prosecution history disclaimer

bears the burden of proving the existence of a ‘clear and

unmistakable’ disclaimer that would have been evident to one

skilled in the art.” Mass. Inst. of Tech. v. Shire Pharm., Inc.,

839 F.3d 1111, 1119 (Fed. Cir. 2016) (citation omitted); see also

Omega Eng’g, Inc., v. Raytek Corp., 334 F.3d 1314, 1324 (Fed.

Cir. 2003) (stating that a disclaimer occurs “where the patentee

has unequivocally disavowed a certain meaning to obtain his

patent”). Said disavowal must be clear and may not be “too vague

or ambiguous[.]” Omega Eng’g, 334 F.3d at 1325 (citation

omitted).

Evidence from sources other than the claims, the

specification, and the prosecution history is extrinsic and

generally should be relied upon only when the intrinsic evidence

fails to resolve any ambiguity in a disputed term. See Vitronics

Corp., 90 F.3d at 1583; see also Phillips, 415 F.3d at 1318–19.

Extrinsic evidence includes “expert and inventor testimony,

dictionaries, and learned treatises.” Markman, 52 F.3d at 980. A

court may use extrinsic evidence to aid its understanding of a

patent, but “not for the purpose of varying or contradicting the

terms of the claims.” Id. at 981 (citations omitted).

Accordingly, the Federal Circuit has stated that “expert

testimony, whether it be of an attorney, a technical expert, or

the inventor, on the proper construction of a disputed claim term

. . . . may only be relied upon if the patent documents, taken as

a whole, are insufficient to enable the court to construe

disputed claim terms.” Vitronics Corp., 90 F.3d at 1585 (emphasis

omitted). In such “rare instances,” prior art documents and

dictionaries are preferable to expert testimony because they are

objective, reliable, and “accessible to the public in advance of

litigation.” Id.

Separate from but related to claim construction is the issue

of patent invalidity for indefiniteness. “[I]ndefiniteness is a

question of law and in effect part of claim construction.” ePlus,

Inc. v. Larson Software, Inc., 700 F.3d 509, 517 (Fed. Cir.

2012). A patent claim is invalid for indefiniteness under 35

U.S.C. § 112 “if its claims, read in light of the specification

delineating the patent, and the prosecution history, fail to

inform, with reasonable certainty, those skilled in the art about

the scope of the invention.” Nautilus, Inc. v. Biosig

Instruments, Inc., 572 U.S. 898, 901 (2014). Like claim

construction, determining invalidity is a legal question for the

court to evaluate. Young v. Lumenis, Inc., 492 F.3d 1336, 1344

(Fed. Cir. 2007) (“A determination that a patent claim is invalid

for failing to meet the definiteness requirement in 35 U.S.C.

§ 112 . . . is a legal question reviewed de novo.”). “The

definiteness requirement must take into account the inherent

limitations of language, but at the same time, the patent must be

precise enough to afford clear notice of what is claimed, thereby

apprising the public of what is still open to them.” Fairfield

Indus., Inc. v. Wireless Seismic, Inc., No. 4:14-CV-2972, 2015 WL

1034275, at *4 (S.D. Tex. Mar. 10, 2015) (citing Nautilus, 572

U.S. at 907–911). “The definiteness requirement ‘mandates

clarity, while recognizing that absolute precision is

unattainable.’” Presidio Components, Inc. v. Am. Tech. Ceramics

Corp., 875 F.3d 1369, 1375 (Fed. Cir. 2017) (quoting Nautilus,

572 U.S. at 910).

A key difference between claim construction versus the issue

of invalidity for indefiniteness relates to burden of proof; in

claim construction, there is no burden of proof assigned to

either party, whereas with invalidity for indefiniteness, patents

are presumed to be valid and the patent challenger has the burden

of proving invalidity by clear and convincing evidence. See

Microsoft Corp. v. I4I Ltd. P’ship, 564 U.S. 91, 95 (2011);

Takeda Pharm. Co. v. Zydus Pharms. USA, Inc., 743 F.3d 1359, 1366

(Fed. Cir. 2014).

II. BRIEF OVERVIEW OF THE ‘633 PATENT

At issue here is the ‘633 Patent, entitled “High-Voltage

Power Semiconductor Device.” (‘633 Patent (Doc. 83-1) at 2.)1 The

Patent claims particular double-implanted MOSFETS, which — at a

high level — act like electric switches allowing or preventing

current to flow from an electrode source to drain. A MOSFET

device switches and regulates current in electric circuits by

creating static electronic fields in a semiconductor material.

1 All citations in this Memorandum Opinion and Order to

documents filed with the court refer to the page numbers located

at the bottom right-hand corner of the documents as they appear

on CM/ECF.

(See Ex. 1, Expert Report of W. Allen Doolittle, Ph.D. Concerning

Construction of Certain Terms in U.S. Patent No. 7,498,633

(“Doolittle Report”) (Doc. 104-1) at 13.) A vertical MOSFET

device consists of several layers: the gate electrode, gate

oxide, source electrodes, a series of semiconductor drift layers

of differing polarities, and a lower drain layer. (Id. at 13–14.)

Current flows through a channel in the drift layer from the

source to the drain. (See id. at 14 n.1.) Applying a static

electric field transverse to the current flow creates a “field

effect” that impacts the conductance of a semiconductor device.

(See id. at 13.)

When a MOSFET device is in the on-state, an electric field

forms across the oxide layer of the device and permeates into the

semiconductor; this creates a channel in which electrons flow

from the source region through the drift layer of the device and

into the drain terminal. (Id. at 15.) In the off-state, there is

a high resistance in the drift layer that blocks voltage applied

to the MOSFET device. (See id. at 15–16.) The JFET region in a

MOSFET device is formed from “pinch[ing] [of] current flow from

source to drain[,] thus increase[ing] . . . resistance.” (Id.

at 17.)

A major “design consideration” in MOSFETS appears to be

balancing a “high blocking voltage” with a low “on-resistance of

the semiconductor device” because a decreased on-resistance

improves the semiconductor device’s efficiency. (‘633 Patent

(Doc. 83-1) at 7.) “However, the typical fabrication techniques

for reducing the specific on-resistance of high-voltage power

semiconductor devices may also reduce the blocking voltage of the

device.” (Id.) As a result, blocking voltage and on-resistance

appear to be inversely correlated, where both a high blocking

voltage and a low on-resistance are desirable. (See id.) “A JFET

region that was too wide would result in the field across the

gate oxide in the blocking state to exceed the electric field for

oxide breakdown, thus damaging the gate oxide.” (Ex. 2, Expert

Report of Stanley Shanfield, Ph.D. (“Shanfield Report”)

(Doc. 103-2) at 17.) “On the other hand, a JFET region that was

too narrow would increase the on-state resistance, contrary to

the design goal” of the MOSFET device. (Id. at 17–18.)

Plaintiff asserts the ‘633 Patent, which is directed towards

high-voltage metal-oxide semiconductor field-effect transistors

with silicon carbide substrates. (‘633 Patent (Doc. 83-1) at 1,

8.) The parties dispute four claim terms in Claims 9 and 10 of

the ‘633 Patent, and the parties’ positions on those terms are

listed below:

Plaintiff’s Defendant’s

Claim Term

Construction Construction

“a first source No construction Claim 9’s use of the

electrode formed necessary terms “first” and

over the first “second” requires

source region” / “a distinct elements

second source (i.e., the “first

electrode formed source electrode”

over the second must be distinct

source region” from the “second

(Claim 9) source electrode”)

“a JFET region No construction Indefinite

defined between the necessary

first source region

and the second

source region”

(Claim 9)

“the JFET region No construction Indefinite

having a width less necessary

than about three

micrometers” (Claim

9)

“the JFET region No construction Indefinite

having a width of necessary

about one

micrometer” (Claim

10, depends from

Claim 9)

III. ANALYSIS

A. “a first source electrode formed over the first source

region” / “a second source electrode formed over the

second source region”

Plaintiff’s Defendant’s

Claim Term

Construction Construction

“a first source No construction Claim 9’s use of the

electrode formed necessary terms “first” and

over the first “second” requires

source region” / “a distinct elements

second source (i.e., the “first

electrode formed source electrode”

over the second must be distinct

source region” from the “second

(Claim 9) source electrode”)

Defendant argues that the use of “first” and “second”

specifying the source electrodes and their positions in Claim 9

requires a covered MOSFET device to have two distinct source

electrodes, one for each source region. (Def.’s Opening Claim

Construction Br. (Doc. 104) at 14–18.) Defendant cites the

express language of the claim term, the drawings included in the

‘633 Patent’s specification, and the ‘633 Patent’s prosecution

history in support. (See id.) Specifically, Defendant argues that

the express language of the claim term uses “first” and “second”

as qualifiers for the “source electrodes,” such that each source

electrode must be a separate and distinct element, not a unitary

source electrode for both source regions on the MOSFET device.

(Id. at 14–15.) Defendant next contends that the specification

further supports this construction because the figures of the

‘633 Patent “consistently illustrate the electrodes as separate

and distinct” and because the specification discusses each source

electrode “respective[]” to each source region.” (Id. at 15–16.)

Finally, Defendant argues that the prosecution history supports

its proposed construction because the terms “first” and “second”

were added as amendments during patent prosecution to

differentiate the ‘633 Patent from a prior art, U.S. Patent

No. 6,573,534 (“the ‘534 Patent”), which uses a unitary source

electrode. (Id. at 16–18.) At the claim construction hearing,

Defendant further refined this argument by contending that while

the first and second source electrodes must be separate and

distinct elements, they may still be electrically connected.

Plaintiff refutes Defendant’s reading of the claim term,

arguing that it is inconsistent with the specification. (Pl.’s

Opening Claim Construction Br. (Doc. 103) at 28–30.) Plaintiff

argues that the claim covers both:

(1) MOSFETS where there are two unique source

electrodes, one formed over the first source region and

one formed over the second source region, and

(2) MOSFETS where there is a single, unitary source

electrode that is spatially separated when forming over

both the first source region and the second source

region.

(Id.) The parties do not dispute that the former MOSFET device

with two unique source electrodes is covered by the ‘633 Patent.

Defendant proposes a construction that narrows the ‘633 Patent;

only the former is covered, and the latter MOSFET device with a

unitary source electrode is outside the Patent’s scope. In

support of its position that no construction is necessary,

Plaintiff references the specification, which states that in some

embodiments, “the source electrodes 50, 52 are coupled together

to form a unitary source electrode.” (Id. at 28 (citing ‘633

Patent (Doc. 83-1) at 10).) Plaintiff argues that this

expressly-contemplated embodiment precludes Defendant’s proposed

narrowing of the claim term. (Id. at 28.) Plaintiff further

argues that the patent prosecution history does not support

Defendant’s proposed construction of the claim term, as an

amendment during prosecution does not amount to an unambiguous

disavowal of any portion of the scope of the claim, including

embodiments explicitly discussed in the specification. (Pl.’s

Responsive Claim Construction Br. (Doc. 117) at 15–16.)

“[T]he claims made in the patent are the sole measure of the

grant,” see Phillips, 415 F.3d at 1312 (quotation omitted), and

the claim language explicitly specifies a “first” and a “second”

source electrode. “The use of the terms ‘first’ and ‘second’ is a

common patent-law convention to distinguish between repeated

instances of an element or limitation.” 3M Innovative Props. Co.

v. Avery Dennison Corp., 350 F.3d 1365, 1371 (Fed. Cir. 2003).

However, the cases Defendant cites for this proposition, although

constructing terms like “first” and “second,” do so in inapposite

contexts. For example, in 3M Innovative Properties, the Federal

Circuit held that numerical terms like “first” and “second” in a

claim term did not impose a serial or sequential order limitation

in the claim. Id. And the court in Gillette Co. v. Energizer

Holdings, Inc. held that numerical terms did not limit the number

of blades on a claim in the invention. 405 F.3d 1367, 1372 (Fed.

Cir. 2005). The types of patented subject matter in both cases

Defendant cites are dissimilar to the present case, and those

cases do not even consider the issue here — whether numerical

terms like “first” or “second” may cover a single element serving

dual roles in the claim.

In contrast, Plaintiff cites to Koninklijke Philips N.V. v.

Wangs All. Corp., which rejected the defendant’s argument that a

“second LED” required a “separate and distinct” light emitting

diode that was not physically and electronically connected to the

“first LED.” No. CV 14-12298-DJC, 2017 WL 6329616, at *11–12 (D.

Mass. Dec. 11, 2017). Like the present case, Koninklijke Philips

N.V. pertains to a patent for a semiconductor device, albeit a

different type of semiconductor. Id. at *1. Additionally, the

construction of “second” in Koninklijke Philips N.V. implicates

similar issues as the present case — whether use of language like

“first” and “second” requires two distinct electricity sources,

or whether a single source that connects to two regions on an

electrode is also covered by the claim language. Id. at *11–12.

Koninklijke Philips N.V. rejected the defendant’s proposed

narrowing of the claim scope and concluded that no construction

was necessary, explaining that the court would “not reinterpret

the claim language where it is sufficiently clear and where the

specification discloses embodiments electronically and physically

grouped together.” Id. at *12.

In light of the specification, the terms “first” and

“second” in the ‘633 Patent do not require the first and second

electrodes to be electrically or physically disconnected, as

Defendant contends. The specification explicitly considers and

includes the possibility of a single source electrode. In its

description of Figure 1, the specification states:

A source metallic electrode 50, 52 is formed over the

source regions 46, 48 respectively. In some

embodiments, the source electrodes 50, 52 are coupled

together to form a unitary source electrode.

. . .

The semiconductor device 10 may be electrically coupled

with other electrical devices, sources, or the like via

the electrodes. . . .

(‘633 Patent (Doc. 83-1) at 10 (emphasis added).) Even though

“the claims made in the patent are the sole measure of the

grant,” a claim term “can be defined only in a way that comports

with the instrument as a whole.” Phillips, 415 F.3d at 1312.

Further, “a claim interpretation that excludes a preferred

embodiment from the scope of the claim is rarely, if ever,

correct.” On-Line Techs., Inc. v. Bodenseewerk Perkin-Elmer GmbH,

386 F.3d 1133, 1138 (Fed. Cir. 2004) (internal citation and

quotations omitted).

The parties do not dispute that embodiments where the source

electrodes are distinct and decoupled are covered within the

scope of the ‘633 Patent. (Compare Pl.’s Opening Claim

Construction Br. (Doc. 103) at 28–30, with Def.’s Opening Claim

Construction Br. (Doc. 104) at 14–18.) The specification

explicitly considers and chooses to include embodiments where a

single electrode is used for both the “first” and the “second”

source regions. (‘633 Patent (Doc. 83-1) at 10.) Defendant’s

proposed construction would narrow the claim to exclude an

expressly-included embodiment. The claim language, in light of

the specification, is “sufficiently clear” and contemplates

MOSFETs with a single unitary source electrode formed over the

“first” and “second” source regions.

Defendant references the ‘633 Patent’s prosecution history

to argue that the March 12, 2008 amendment to Claim 9 — which

added the “first” and “second” language at issue to Claim 9 —

shows that the claim was amended to require a distinct “first

source electrode” and “second source electrode” to distinguish

the ‘633 Patent from a prior art with a single unitary source

electrode. (Def.’s Opening Claim Construction Br. (Doc. 104)

at 16–17, see also Ex. C (Doc. 104-3) at 42.) However, the

amendment alone does not demonstrate that its purpose was to

distinguish from a prior art that included a single source

electrode, particularly as the remarks to that amendment show

that the amendment was also in response to the Patent Examiner’s

proposed combination of three different prior art references.

(See Ex. C (Doc. 104-3) at 10–11, 47–48.) Finding disclaimer of

claim scope based on prosecution history requires “a clear and

unmistakable disavowal of scope during prosecution.” Purdue

Pharma L.P. v. Endo Pharm. Inc., 438 F.3d 1123, 1136 (Fed. Cir.

2006). Ambiguous statements in prosecution history are not enough

to support limiting claim scope, particularly when the

applicant’s statements may be subject to multiple

interpretations. SanDisk Corp. v. Memorex Prods., Inc., 415 F.3d

1278, 1287 (Fed. Cir. 2005) (“There is no ‘clear and

unmistakable’ disclaimer if a prosecution argument is subject to

more than one reasonable interpretation, one of which is

consistent with a proffered meaning of the disputed term.”). The

amendment alone, given the specification’s inclusion of an

embodiment with a unitary source electrode, is not a “clear and

unmistakable disavowal of scope.” See Purdue Pharma L.P., 438

F.3d at 1136.

In sum, reading the “instrument as a whole,” see Phillips,

415 F.3d at 1316, this court concludes that no construction is

necessary for the term “a first source electrode formed over the

first source region” and “a second source electrode formed over

the second source region.”

Defendant also raises the issue that the ‘534 Patent already

covers a MOSFET with a unitary source electrode. (Def.’s Opening

Claim Construction Br. (Doc. 104) at 16–18.) Plaintiff’s proposed

construction of the ‘633 Patent, which this court adopts,

explicitly contemplates a unitary source electrode. Defendant

argues that during prosecution of the ‘633 Patent, Plaintiff

amended the claim at issue to specifically distinguish from the

‘534 Patent’s use of a unitary source electrode. (Id.) However,

invalidity due to anticipation by a prior art reference is a

factual question for summary judgment or trial. See Oney v.

Ratliff, 182 F.3d 893, 895 (Fed. Cir. 1999) (“Although

anticipation is a question of fact, it still may be decided on

summary judgment if the record reveals no genuine dispute of

material fact.”). This court need not reach this issue during

claim construction.

B. “a JFET region defined between the first source region

and the second source region”

Plaintiff’s Defendant’s

Claim Term

Construction Construction

“a JFET region No construction Indefinite

defined between the necessary

first source region

and the second

source region”

(Claim 9)

Defendant argues that the claim term — “a JFET region

defined between the first source region and the second source

region” — is indefinite because of an alleged inconsistency

between the term’s plain language (which requires the JFET region

to be bordered by the first and second source regions), and the

specification (which defines the JFET region as bound by the two

p-wells). (Def.’s Opening Claim Construction Br. (Doc. 104)

at 19–20.) Relying on testimony from its expert, Dr. Doolittle,

Defendant argues that this inconsistency between the claim term

and the specification means that the width of the JFET region

will vary depending on the boundaries from which it is measured.

(Id. at 20–21.) Dr. Doolittle explains that the explicit claim

language “results in the JFET region including a portion of the

first and second p-well regions 26 and 28.” (Doolittle Report

(Doc. 104-1) at 26.) However, he opines that “the specification

and figures of the ‘633 Patent describe the JFET region as

distinct from and defined between the p well regions of the

device.” (Id.)

Defendant contends that this inconsistency is meaningful

because the “variability could mean that a given MOSFET device

falls within or outside the scope of the claims depending on

where it is measured,” either “between the source regions or

p-wells.” (Def.’s Opening Claim Construction Br. (Doc. 104)

at 21.) Dr. Doolittle proffers an example, in which a MOSFET

device falls outside the scope of the ‘633 Patent when the JFET

region is defined between and measured between the source regions

(as stated in the claim language), while that MOSFET device falls

within the scope of the ‘633 Patent when the JFET region is

defined between and measured between the p-wells (as described in

the specification). (Doolittle Report (Doc. 104-1) at 28–29.)

According to Defendant, this inconsistency raises a “zone of

uncertainty” rendering the claim term indefinite, as the claim

term “is open to multiple interpretations reflecting markedly

different understandings of the patent’s scope.” (Def.’s Opening

Claim Construction Br. (Doc. 104) at 22 (quoting Nautilus, 572

U.S. at 909, 913).)

Defendant also argues that, regardless of whether the JFET

region is defined between the source regions or the p-wells, the

‘633 Patent fails to specify where the JFET region’s width is

measured, which varies due to the curvature of the p-well

boundaries. (Id. at 23–24.) Again, Defendant contends that a

given MOSFET device may fall within or outside the scope of the

‘633 Patent depending on where the JFET region’s width is

measured, creating an ambiguity rendering the claim term

indefinite. (Id. at 24, 26.)

Plaintiff argues that Defendant’s contention of

indefiniteness is pretextual because Defendant understood the

location of the JFET region during inter partes review of the

‘633 Patent.2 (Pl.’s Opening Claim Construction Br. (Doc. 103)

at 15–16.) Additionally, Plaintiff argues that the claim term is

not indefinite in light of the specification; instead, Plaintiff

2 Plaintiff’s argument concerning Defendant’s position

during inter partes review of the ‘633 Patent is not convincing.

The standard of review in an IPR proceeding is different from

that in district court litigation. In an IPR proceeding, the

burden of proving a claim invalid is preponderance of the

evidence. 35 U.S.C. § 316(e). However, when evaluating a claim

as invalid for indefiniteness, the patent challenger must prove

a claim invalid by clear and convincing evidence. Microsoft

Corp., 564 U.S. at 95; Takeda Pharm. Co., 743 F.3d at 1366.

Further, “[t]he statutory provisions governing the inter partes

review process do not permit the Board to institute inter partes

review of claims for indefiniteness. . . . [T]he petitioner in

the IPR proceeding below [is] thus not permitted to request that

the Board cancel claims . . . on the ground that they were

indefinite. Nor [can] the Board cancel those claims as

indefinite on its own accord.” Samsung Elecs. Am., Inc. v.

Prisua Eng’g Corp., 948 F.3d 1342, 1350–51 (Fed. Cir. 2020).

Thus, whether or not Defendant raised particular issues before

the Patent Trial and Appeal Board does not limit Defendant’s

arguments concerning indefiniteness before this court.

suggests Defendant’s expert narrows in on the claim term without

context of the specification to argue that the term is

indefinite. (Id. at 18–20.) More specifically, Plaintiff argues

that “the specification informs the claims by stating that the

JFET region is between the p well regions, thereby pointing to

exactly where the JFET region should be measured in the space

between the first source region and the second source region.”

(Pl.’s Responsive Claim Construction Br. (Doc. 117) at 7.) In

short, Plaintiff argues that the claim and specification are

consistent because “the JFET region is located between the p

wells, which also falls between the first source region and the

second source region.” (Id.)

Plaintiff also refutes Defendant’s argument concerning a

lack of guidance on where the JFET region’s width should be

measured, explaining that “the JFET region should be measured at

the narrowest point to achieve the intended design.” (Id. at 9.)

This is because Plaintiff contends a person of skill in the art

would know there is an optimum width that furthers the MOSFET

device’s design goal of “achiev[ing] the lowest possible

on-resistance while meeting the desired blocking voltage

specification.” (Id. (quoting Shanfield Report (Doc. 103-2)

at 17–18).)

This court finds that there is no inconsistency between the

claim term and the specification rendering the claim term

indefinite. However, this court, in a separate order, will

request supplemental briefing on the discrete argument Defendant

raises concerning where the JFET region’s width is measured.

Addressing Defendant’s argument concerning a purported

inconsistency between the claim term and the specification, this

court starts with intrinsic evidence, as “it is improper to rely

on extrinsic evidence” when intrinsic evidence alone will resolve

any ambiguity. See Vitronics Corp., 90 F.3d at 1583. Considering

the claim term itself and the ordinary meaning that would be

attributed to the term by a person skilled in the relevant art,

“defined between” is a clear term that, by its plain language,

delineates or establishes the outer boundaries of the “JFET

region.” “There is a heavy presumption that claim terms are to be

given their ordinary and customary meaning.” Aventis Pharm. Inc.

v. Amino Chems. Ltd., 715 F.3d 1363, 1373 (Fed. Cir. 2013).

“Defined between” is used so ubiquitously in patent

specifications that this court has not found any caselaw

providing a precise and unambiguous definition of “defined” or

“defined between.” Even so, it is commonly used as a term to

delineate boundaries. See, e.g., Ascion, LLC v. Ashley Furniture

Indus., Inc., No. 2021-1857, 2022 WL 1197338, at *1 (Fed. Cir.

Apr. 22, 2022) (“body portion having a first top-to-bottom length

defined between the top edge and bottom surface”) (emphasis

added); Campbell Soup Co. v. Gamon Plus, Inc., No. 2020-2322,

2021 WL 3671366, at *1 (Fed. Cir. Aug. 19, 2021) (“The chutes 22,

24 are defined between adjacent pairs of panels 10 and are of a

width slightly greater than the width of products 90 [(e.g., soup

cans)] and which allow the products to be stored and dispensed

therefrom.”) (emphasis added); In re Smolak, 88 F.2d 838, 839

(C.C.P.A. 1937) (“intermediate portions of irregularly sloping

surfaces defined between the said elevated and depressed

portions”) (emphasis added). Accordingly, the claim term “defined

between” establishes the absolute boundaries of the “JFET region”

as the “first source region” and the ”second source region.”

However, the claim term must also be considered in light of

the entire ‘633 Patent, including the specification and drawings.

Cf. Funai Elec. Co. v. Daewoo Elecs. Corp., 616 F.3d 1357, 1371

(Fed. Cir. 2010) (“We affirm the district court’s claim

construction, for it is in accordance with the specification

including the drawings . . . .”). In Figure 1, the JFET region 30

is bounded on the left by p-well 26 and on the right by p-well

28. (‘633 Patent (Doc. 83-1) at 3.) In alignment with the claim

term, in Figure 1, the JFET region 30 is also between the first

source region on the left and the second source region on the

right. (Id.) Further, Claim 9 provides a range for the JFET

region’s possible width, and Dr. Shanfield explains that the JFET

region’s width may vary to optimize for “the lowest possible

on-resistance while meeting the desired blocking voltage

specification.” (Shanfield Report (Doc. 103-2) at 17.) As a

result, the JFET region must fall between the p-wells, as well as

the first and second source regions; even if the JFET region is

precisely bounded by the first and second source regions, it

still falls within the p-wells. Figure 1’s description in the

specification supports this construction of the claim term:

As illustrated in FIG. 1, the semiconductor device 10

also includes source regions 46, 48 defined in the “P”

wells 26, 28, respectively.

(‘633 Patent (Doc. 83-1) at 9 (emphasis added).) By the claim

specification, the first and second source regions are “in” the

p-wells, or at least overlap in location with the p-wells. (Id.)

Thus, although the claim term is arguably less precise than the

specification, the two are not inconsistent such that a person

skilled in the relevant art or the public would be unable to

understand the scope of the claim. The claim term, specification,

and Figure 1 taken together demonstrate the JFET region falls

between both the source regions and the p-wells, particularly

since the specification defines the source regions as “in” the

p-wells themselves. (See id. at 9.)

In support of its argument for indefiniteness, Defendant

cites to Allen Eng’g Corp. v. Bartell Indus., Inc., 299 F.3d 1336

(Fed. Cir. 2002) and Juxtacomm-Texas Software, LLC v. Axway,

Inc., No. 6:10CV011, 2012 WL 7637197 (E.D. Tex. July 5, 2012),

aff’d sub nom. JuxtaComm-Texas Software, LLC v. TIBCO Software,

Inc., 532 F. App’x 911 (Fed. Cir. 2013). (Def.’s Responsive Claim

Construction Br. (Doc. 118) at 11–12.) However, the alleged

inconsistency here is not like Allen Eng’g Corp., in which the

plaintiff unsuccessfully tried to claim a person skilled in the

relevant art would read “perpendicular” to mean “parallel.” 299

F.3d at 1349. A lack of specificity in the claim term, when the

specification provides that further detail, like here, is not

akin to claiming the opposite meaning of a word. Juxtacomm-Texas

Software is also not a meaningful comparison. In Juxtacomm-Texas

Software, the claims at issue stated that “data transformation

must occur within the systems interface,” whereas the patent

specification explained that the “systems interface merely

defines the scripts that perform data transformation.” 2012 WL

7637197, at *5–6. Whether an interface performs a particular task

outright or whether it writes a script that performs a task are

two different pieces of software. The issue in the present case

appears to be lack of precision, not a contradiction between the

claim and specification.

Accordingly, considering both the language of the claim and

the specification together, a person skilled in the relevant art

is informed “with reasonable certainty” of “the scope of the”

claim term “a JFET region defined between the first source region

and the second source region,” so it is not indefinite on those

grounds. See Nautilus, 572 U.S. at 901.

C. “the JFET region having a width less than about three

micrometers” and “the JFET region having a width of

about one micrometer”

Plaintiff’s Defendant’s

Claim Term

Construction Construction

“the JFET region No construction Indefinite

having a width less necessary

than about three

micrometers” (Claim

9)

“the JFET region No construction Indefinite

having a width of necessary

about one

micrometer” (Claim

10, depends from

Claim 9)

Defendant argues that both of these claim terms are

indefinite because the ‘633 Patent does not provide objective

boundaries for the JFET region’s width. (Def.’s Opening Claim

Construction Br. (Doc. 104) at 22–27.) Specifically, Defendant

argues that the claim term — “the JFET region having a width less

than about three micrometers” — is indefinite because the claim

term does not provide an upper or lower bound for the JFET

region’s width and because of the use of the word “about.” (Id.

at 27–33.) And Defendant argues that the claim term — “the JFET

region having a width of about one micrometer” — is indefinite

for the same reasons. (Id. at 33.) Defendant also appears to

restate this argument in other words in its responsive brief by

arguing that “[t]he patent fails to specify an objective upper

boundary.” (Def.’s Responsive Claim Construction Br. (Doc. 118)

at 15 (cleaned up).)

Plaintiff argues that Defendant’s argument about a lack of

objective bounds lacks merit because a person skilled in the

relevant art would know not to create a MOSFET with a JFET region

width of zero that renders the MOSFET inoperable. (Pl.’s Opening

Claim Construction Br. (Doc. 103) at 22–25.) Additionally,

Plaintiff argues that the word “about” is not indefinite given

inevitable variations in manufacturing processes. (Id. at 25–28.)

First, the use of the term “about” does not render either

claim term indefinite. “About” has an “ordinary meaning of

‘approximately.’” Merck & Co. v. Teva Pharms. USA, Inc., 395 F.3d

1364, 1369 (Fed. Cir. 2005). And neither the claims, nor the

specification, suggest the patentee has redefined the term

“about” away from its ordinary meaning. See id. at 1370. Thus,

the claim term “the JFET region having a width less than about

three micrometers” can be construed as meaning “the JFET region

having a width less than approximately three micrometers.” The

claim term “the JFET region having a width of about one

micrometer” can be construed as meaning “the JFET region having a

width of approximately one micrometer.”

In this context, “‘about’ is properly described as a ‘word

of degree’ or ‘term of degree.’” See Enviro Tech Chem. Servs.,

Inc. v. Safe Foods Corp., No. 4:21-CV-00601-LPR, 2022 WL

17721179, at *13 (E.D. Ark. Dec. 15, 2022). “Other courts have

found claim terms of approximation such as ‘about’ to have

sufficiently definite meaning on the basis of manufacturing

tolerances and/or rounding.” Glaukos Corp. v. Ivantis, Inc.,

No. SACV 18-620 JVS (JDEx), 2019 WL 8955768, at *11 (C.D. Cal.

Aug. 16, 2019) (collecting cases). Even so, terms of degree must

be sufficiently definite. Berkheimer v. HP Inc., 881 F.3d 1360,

1364 (Fed. Cir. 2018) (“Our case law is clear that the objective

boundaries requirement applies to terms of degree.”).

The ‘633 Patent uses the term “about” as a “term of degree”

to account for such manufacturing tolerances or variations, and

“about” is sufficiently definite as used in the ‘633 Patent.

Dr. Shanfield explains on behalf of Plaintiff that fabrication of

MOSFET devices “necessarily results in minor variations in

feature dimensions because of the equipment used and the

microscopic feature sizes.” (Shanfield Report (Doc. 103-2) at

16.) He explains that “while the average measurements of a device

will be close to the specified value across the thousands of dice

on a semiconductor device, any two devices made using the same

fabrication process will have some minor deviation from this

average.” (Id. at 16–17.) The manufacturing variations that

impact the width of the JFET region depend on several factors,

including transverse straggle and critical dimension tolerance.

(Id. at 17.) A person skilled in the art would understand that

the width of the JFET region depends upon a careful balance

between “the lowest possible on-resistance while meeting the

desired blocking voltage specification.” (Id.) A person skilled

in the art would also be informed about the JFET region’s width

by existing design criteria and by published literature. (Id.

at 18.) Accordingly, a person skilled in the relevant art would

know that while the JFET width can be specified precisely during

the design phase, “the JFET width after fabrication cannot be

specified to exact values,” only “a distribution with range and

standard deviation.” (Id. at 17.)

Dr. Doolittle acknowledges the possibility of manufacturing

variation, but he argues that “there is no universal or accepted

degree of variation that is considered acceptable in the field of

MOSFET design.” (Doolittle Report (Doc. 104-1) at 43.)

Specifically, he explains that “the degree of acceptable

variation depends on design goals [and] constraints,” but “the

‘633 Patent fails to specify any of those parameters that would

help a person of ordinary skill in the art understand the

acceptable degree of variation.” (Id. at 44.)

Using a term of degree, which permeates patent claims, is

not enough to render the claim term indefinite. Defendant demands

the claim include a numerical range of error to clarify the

meaning of “about,” but the Federal Circuit frequently refuses to

impose a more exact or numerically precise construction on terms

of degree. See, e.g., Anchor Wall Sys. v. Rockwood Retaining

Walls, Inc., 340 F.3d 1298, 1310–11 (Fed. Cir. 2003) (“[T]he

phrase ‘generally parallel’ envisions some amount of deviation

from exactly parallel,” and “words of approximation, such as

‘generally’ and ‘substantially,’ are descriptive terms commonly

used in patent claims to avoid a strict numerical boundary to the

specified parameter.”). Dr. Shanfield’s explanation that a person

skilled in the art would know to optimize “achiev[ing] the lowest

possible on-resistance while meeting the desired blocking voltage

specification,” (Shanfield Report (Doc. 103-2) at 17), when

designing a MOSFET device is akin to defining the patent term in

“functional terms, thereby saving it from indefiniteness.” See

Automated Packaging Sys., Inc. v. Free Flow Packaging Int’l,

Inc., No. 18-CV-00356-EMC, 2018 WL 3659014, at *17 (N.D. Cal.

Aug. 2, 2018) (explaining that the term “substantial” is a “term

of degree” that is rendered sufficiently definite because the

patent specification provides a functional purpose for the term).

In Automated Packaging Sys., the term “substantially” was

found sufficiently definite when used in the phrase,

“longitudinally spaced transverse lines . . . extending

substantially from the side edge to the fill edge,” even though

the patent claims and specification did not define “substantially

extend.” Id. at *15–16. This is because the court found the claim

language to be “defined in functional terms,” where the “function

of the transverse lines . . . is to permit facile separation of

the pouches.” Id. at *17. The range of the transverse lines’

possible lengths was finite, and a person skilled in the art

could test to determine what length allowed “facile separation of

the pouches,” depending on “the tensile strength and thickness of

the web material.” Id.

In Biosig Instruments, the Federal Circuit also found terms

of degree to be sufficiently definite when the terms depended on

the function of the claimed material. 783 F.3d at 1382-84. The

Federal Circuit held that a “spaced relationship” between

electrodes in a heart rate monitor was a sufficiently definite

term with proper bounds because the patent provided objective

standards that a person skilled in the art could test to ensure

the electrodes satisfied their function within the patent. Id.

For example, one objective standard included testing for the

“substantial removal of EMG signals from ECG signals.” Id.

at 1384 (quoting Biosig Instruments, Inc. v. Nautilus, Inc., 715

F.3d 891, 900–01 (Fed. Cir. 2013), vacated, 572 U.S. 898 (2014)).

Here too, “about” is sufficiently definite because the ‘633

Patent informs a person skilled in the art of the JFET width’s

function, which is to optimize between a lower on-resistance and

desired blocking voltage. (Shanfield Report (Doc. 103-2) at 17.)

A person skilled in the art could test the on-resistance and

blocking voltage to ensure the two are optimized to serve the

purpose of the MOSFET device, like how a person skilled in the

art could test for removal of EMG signals from ECG signals in

Biosig Instruments. See 783 F.3d at 1384. Accordingly, “about” is

a sufficiently definite term of degree in the claim term and does

not render the claim terms indefinite.

Relatedly, the lack of an upper bound does not render the

claim term “the JFET region having a width less than about three

micrometers” — indefinite. The claim term explicitly provides an

upper boundary of “three micrometers,” and the use of “about”

accounts for manufacturing variation during fabrication even when

the JFET width is “specified to exact values” during the “design

phase.” (See Shanfield Report (Doc. 103-2) at 17.)

Second, the lack of a lower bound does not render the claim

term — “the JFET region having a width less than about three

micrometers” — indefinite. While Defendant agrees that a width of

zero is “outside the scope of the claim because . . . [it] would

render the MOSFET device inoperable,” Defendant poses “the

question [of] what the minimum allowable width is.” (Def.’s

Opening Claim Construction Br. (Doc. 104) at 27.) However, when

the claim does not contain a lower bound, the claim “expressly

reach[es]” all operable devices with a “JFET region having a

width less than about three micrometers.” See Exxon Rsch. & Eng’g

Co. v. United States, 265 F.3d 1371, 1382 (Fed. Cir. 2001)

(explaining that a claim that did not include an upper limit on

particle diameter “expressly reach[ed]” all such particles with a

diameter greater than the stated minimum, and that “no limitation

[was] required as a matter of definiteness”). Failure to include

a size bound does not render a patent indefinite, as a person

skilled in the relevant art would know to create an operable

MOSFET under the guideline of a JFET region with a width less

than “about three micrometers.” Plaintiff agrees that “any

operable device with a JFET width less than about three

micrometers meets the claim limitation.” (Pl.’s Responsive Claim

Construction Br. (Doc. 117) at 11.) Defendant’s expert,

Dr. Doolittle, makes the same point. (Doolittle Report

(Doc. 104-1) at 42 (“The patent does not limit the JFET width to

a minimum of one micron or disclaim values between zero and

one.”).) This is particularly true when a shorter JFET region

width is desirable for reducing the on-resistance of the MOSFET,

thereby increasing its efficiency. A person skilled in the

relevant art is informed, “with reasonable certainty,” of “the

scope of the invention,” so the lack of a lower bound does not

render the claim term indefinite. See Nautilus, 572 U.S. at 901.

Although merely persuasive to this court, the Western

District of Texas, when also construing “about three micrometers”

in the ‘633 Patent for indefiniteness, reached the same

conclusion. See Claim Construction Order and Memorandum in

Support Thereof at 30, Trustees of Purdue Univ. v.

STMicroelectronics Int’l N.V., No. 6:21-cv-727-ADA-DTG (W.D. Tex.

Dec. 14, 2022), Doc. 220.3

Third, the claim term — “the JFET region having a width of

about one micrometer” — is not indefinite due to the use of the

word “about” or due to the lack of a “range of acceptable widths

above and below one micron.” (Def.’s Opening Claim Construction

3 The parties in the Western District of Texas litigation

did not raise the issue of whether the ‘633 Patent specifies

where the JFET region’s width is measured. Accordingly, this

court does not find the Western District of Texas’s construction

of the term, “about three micrometers,” persuasive to the degree

that term may be rendered indefinite based on Defendant’s concern

about where the JFET region’s width is measured.

Br. (Doc. 104) at 33.) As explained previously, the use of terms

of degree like “about” do not render a claim indefinite. A width

of “about” or “approximately” one micrometer appears

straightforward on its face, requiring no narrowing of the claim

scope. See, e.g., Home Diagnostics, Inc. v. LifeScan, Inc., 381

F.3d 1352, 1358 (Fed. Cir. 2004) (“Absent a clear disavowal or

contrary definition in the specification or the prosecution

history, the patentee is entitled to the full scope of its claim

language.”). This claim term is in Claim 10, which is dependent

on Claim 9. As such, reading Claim 10 in context of Claim 9, even

if an upper bound is necessary, a person skilled in the relevant

art would understand there to be an upper bound to the JFET

region’s width of “about three micrometers.” Accordingly, this

claim term informs a person skilled in the relevant art “with

reasonable certainty” of “the scope of the invention,” so it is

not indefinite. See Nautilus, 572 U.S. at 901.

In sum, this court finds that neither of those two claim

terms are indefinite based on the arguments presented and that no

construction is necessary. However, as will be addressed in a

separate order, this court is concerned that Defendant’s argument

about the ‘633 Patent’s lack of guidance on where the JFET

region’s width is measured may impact this court’s conclusions

concerning the term “width” within the two claim terms at issue

here.

Iv. CONCLUSION

For the foregoing reasons, this court construes the disputed

terms as follows:

Court’s Construction

“a first source electrode No construction necessary

formed over the first source

region” / “a second source

electrode formed over the

second source region” (Claim

9)

“a JFET region defined between |No construction necessary

the first source region and

the second source region”

(Claim 9)

“the JFET region having a No construction necessary,

width less than about three subject to supplemental

micrometers” (Claim 9) briefing

“the JFET region having a No construction necessary,

width of about one micrometer” | subject to supplemental briefing

(Claim 10, depends from Claim

9)

IT IS SO ORDERED.

This the 7th day of August, 2023.

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