REBECCA BEACH SMITH, District Judge.
This matter comes before the court for claim construction. On April 18, 2011, the court conducted a hearing pursuant to Markman v. Westview Instruments, Inc., 517 U.S. 370, 372, 116 S.Ct. 1384, 134 L.Ed.2d 577 (1996) ("Markman hearing"), and heard argument from both parties as to the meaning of the terms in the disputed claims of the patents at issue. This Opinion details the court's claim construction and explains its reasoning. See MercExchange LLC v. eBay, Inc., 401 F.3d 1323, 1329 (Fed.Cir.2005), vacated on other grounds, eBay, Inc. v. MercExchange LLC, 547 U.S. 388, 126 S.Ct. 1837, 164 L.Ed.2d 641 (2006).
This case involves the alleged infringement of U.S. Patent Number 6,562,130 ("the '130 patent") and U.S. Patent Number 6,534,026 ("the '026 patent"), which are owned by The Fox Group, Inc. ("Fox") and relate to growth of silicon carbide (SiC), a semiconductor material composed of silicon and carbon. Fox filed suit on June 29, 2010, seeking injunctive relief against alleged patent infringement by Cree, Inc. ("Cree"), as well as compensatory damages.
Pursuant to this court's 16(b) scheduling order and a subsequent order extending filing times, the parties submitted their initial claim construction briefs on January 28, 2011, their reply claim construction briefs on February 10, 2011, and their joint claim construction brief on February 24, 2011. On March 8, 2011, this court scheduled a Markman hearing to aid the court in construing the disputed terms of the two patents. The court held the Markman hearing on April 18, 2011, and heard argument on the issue of claim construction. At the end of the hearing, the court took the matter under advisement and permitted the parties to submit post-hearing submissions on or before April 29, 2011. On April 29, 2011, Fox and Cree each filed a supplemental claim construction brief.
SiC crystal is a semiconductor material grown via man-made methods and used in
The inventions set forth in the two patents at issue purportedly enable growth of commercially viable, low-defect single crystal SiC. SiC grown by utilizing the specific seeded sublimation method and apparatus set forth in each patent should contain low levels of those defects typically associated with SiC crystal growth: dislocations, micropipes, and secondary phase inclusions. The '130 patent describes low-defect SiC growth away from the seed crystal in an "axial" direction. The '026 patent also describes low-defect SiC growth away from the seed crystal, but it describes the growth in both an axial and a "lateral" direction.
The '130 patent is entitled "Low Defect Axially Grown Single Crystal Silicon Carbide." It contains twenty-six (26) claims, all of which assert certain properties of SiC material grown by utilizing the method and apparatus provided for in the '130 patent. Independent claims 1, 7, 13, and 19 are at issue in this proceeding. With one exception, claims 1, 7, and 13 are identical. All three claims assert:
See '130 patent col.8 11.6-11 and 39-44, Ex. I to Compl., ECF No. 1-9 [hereinafter "'130 patent"]; id. col.9 11.4-9. The exception is that each claim specifies a different "density of dislocations": claim 1 requires a density of dislocations of less than 10
Claim 19 is similar to claim 1. It requires "silicon carbide material" having the same density of dislocations, the same density of micropipes, and the same density of secondary phase inclusions as required in claim 1. Unlike claim 1, however, claim 19 requires a "silicon carbide seed crystal," id. col.9 1.38, and "a region of axially re-crystallized silicon carbide . . . initiating at [the] growth surface of . . . [the] seed crystal.'" Id. cols.9 1.41-10 1.1. The differences in claim 19 as compared to claim 1 are underscored below for ease of comparison:
Id. cols.9 1.37-10 1.6 (emphasis added).
The '026 patent is entitled "Low Defect Density Silicon Carbide." It consists of fourteen (14) claims, all of which assert certain properties of a SiC material grown by utilizing the method and apparatus provided for in the '026 patent. Independent claims 1 and 7 are at issue in this suit. They are similar. Their differences are underscored below in claim 7 for ease of comparison:
1. A silicon carbide material comprising:
7. A silicon carbide material comprising:
'026 patent, cols. 10 1.18-11 11.21, Ex. F to Compl., ECF No. 1-6 [hereinafter "'026 patent"] (emphasis added); see Cree's Opening Claim Construction Br. 9, ECF No. 54 [hereinafter "Cree's Opening Br."] (explaining that claim 7, instead of referring to "axial" and "lateral" regions like claim 1, refers to "first" and "second" regions).
Claim construction is a matter of law to be decided by the court. Markman, 517 U.S. at 372, 116 S.Ct. 1384. The goal of such construction is to "discern the meaning of [a] term in the context of [the] invention and field of art." Curtiss-Wright Flow Control Corp. v. Velan, Inc., 438 F.3d 1374, 1379 (Fed.Cir.2006). In performing this function, the court need only construe disputed terms of disputed claims of the patent to the extent necessary to resolve the controversy. See NTP, Inc. v. Research In Motion, Ltd., 418 F.3d 1282, 1311 (Fed.Cir.2005) (citing Vivid Techs., Inc. v. Am. Sci. & Eng'g, Inc., 200 F.3d 795, 803 (Fed.Cir.1999)).
Sitting en banc, the Federal Circuit gave an overview of claim construction in Phillips v. AWH Corp., 415 F.3d 1303 (Fed.Cir.2005). Overall, claim construction aims to determine the "meaning that the term would have to a person of ordinary skill in the art in question at the time of the invention, i.e., as of the effective filing date of the patent application." Id. at 1313 (emphasis added). In some instances, a term's ordinary meaning "may be readily apparent even to lay judges, and claim construction in such cases involves little more than the application of the widely accepted meaning of commonly understood words." Id. at 1314. However, when the term's meaning is not readily apparent, courts must consult "those sources available to the public that show what a person of skill in the art would have understood disputed claim language to mean." Id. (citations and internal quotation marks omitted). Those sources include both intrinsic evidence, such as the claims, specification and prosecution history, and extrinsic evidence, such as technical dictionaries, treatises and expert testimony. See Chamberlain Group, Inc. v. Lear Corp., 516 F.3d 1331, 1335 (Fed.Cir. 2008). Intrinsic evidence is considered to be "more reliable" than extrinsic evidence, id., and thus it should be the court's "primary focus in determining the ordinary and customary meaning." Atofina v. Great Lakes Chem. Corp., 441 F.3d 991, 996 (Fed.Cir.2006).
The claim construction process begins with the words of the claims themselves, Old Town Canoe Co. v. Confluence Holdings Corp., 448 F.3d 1309, 1315 (Fed. Cir.2006), focusing on the context in which the term is used. Phillips, 415 F.3d at 1314. "It is a bedrock principle of patent law that the claims of a patent define the invention to which the patentee is entitled the right to exclude." Id. at 1312 (citations and internal quotation marks omitted). Each disputed term is to be given its ordinary and customary meaning. See id. In seeking the plain meaning, the court is concerned with fair notice to the public concerning the scope of the claims. Johnson & Johnston Assocs., Inc. v. R.E. Serv. Co., 285 F.3d 1046, 1052 (Fed.Cir.2002). Because claim terms are normally used consistently throughout the patent, other claims, both asserted and unasserted, may be instructive as to the meaning of the disputed term. Phillips, 415 F.3d at 1314. Differences among claims may also be helpful, as limitations in dependent claims
The claims, however, "do not stand alone" and must be "read in view of the specification, of which they are a part." Id. at 1315 (citations and internal quotation marks omitted). The entirety of the specification is relevant to claim construction, including the abstract, summary and preferred embodiment. See generally Lucent Techs., Inc. v. Gateway, Inc., 525 F.3d 1200 (Fed.Cir.2008) (examining the entirety of the specification in performing claim construction). 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 (citations and internal quotation marks omitted). Further, if the specification reveals "a special definition given to a claim term by the patentee that differs from the meaning it would otherwise possess," then "the inventor's lexicography governs." Id. at 1316; see Edwards Lifesciences LLC v. Cook Inc., 582 F.3d 1322, 1329 (Fed.Cir. 2009). The patentee must, however, "clearly express that intent in the written description." Helmsderfer v. Bobrick Washroom Equip., Inc., 527 F.3d 1379, 1381 (Fed.Cir.2008). The specification may also limit the scope of the invention through an intentional disclaimer or disavowal. Phillips, 415 F.3d at 1316. Nevertheless, it is important that the court "avoid the danger of reading limitations from the specification into the claim," as "persons of ordinary skill in the art rarely would confine their definitions of terms to the exact representations depicted in the embodiments." Id. at 1323.
In addition to the claims and specification, the court may also consider the prosecution history, which "consists of the complete record of the proceedings before the [Patent and Trademark Office] and includes the prior art cited during the examination of the patent." Id. at 1317. Although the prosecution history provides evidence of how the Patent and Trademark Office ("PTO") and the inventor understood the patent, the court must keep in mind that because it "represents an ongoing negotiation between the PTO and the applicant, rather than the final product of that negotiation, it often lacks the clarity of the specification and thus is less useful for claim construction purposes." Id.
As far as extrinsic evidence, the court is not "barred from considering any particular sources or required to analyze sources in any specific sequence, as long as those sources are not used to contradict claim meaning that is unambiguous in light of the intrinsic evidence." Id. at 1324. The district court, in its discretion, may admit extrinsic evidence to help educate itself about the field of the invention in order to determine how a person of ordinary skill in the art would understand the claim terms. Id. at 1319.
The parties do not always agree on which terms in a claim require construction. In several instances, Fox proposes a phrase be construed as one term, whereas Cree parses that phrase into separate terms and seeks their separate construction. In such cases, the court begins with Fox's proposed term, and, to the extent necessary to resolve the controversy, separately construes the component terms as proposed by Cree. In other instances, Cree seeks construction of a phrase, whereas Fox proposes construction of only part of that phrase. In those cases, the court construes claim terms to the extent necessary to resolve the parties' dispute, "to clarify and when necessary to explain what the patentee covered by the claims, for use in the determination of infringement."
The court construes the following four terms found in claims 1, 7, 13 and 19:(1) "axial region of re-crystallized single crystal silicon carbide"/"region of axially recrystallized silicon carbide,"
Fox proposes that the phrases "axial region of re-crystallized single crystal silicon carbide," which appears in claims 1, 7, and 13, and "region of axially re-crystallized silicon carbide," which appears in claim 19, be construed as one term that is applicable across the claims. See Am. Piledriving Equip., Inc. v. Geoquip, Inc., 637 F.3d 1324, 1333 (Fed.Cir. 2011) ("Where a claim term is used consistently throughout the claims, `the usage of [the] term in one claim can often illuminate the meaning of the same term in other claims.'"). Fox's proposed construction is "a portion of a bulk crystal grown in a direction toward the source substantially perpendicular to the seed crystal plane by physical vapor transport."
Cree proposes different terms be construed. Specifically, Cree proposes that "axial" and "axially" be construed as one term that is applicable across the claims, see id., and that "re-crystallized" be separately construed. Cree's proposed construction for "axial [region]"
There is no apparent utility in parsing Fox's proposed term in order to construe the claims and resolve the dispute. Even if the court separately construes "axial," "axially," and "re-crystallized," those terms must be reconciled to provide a coherent meaning for the claim as a whole. Indeed, Cree concedes this by highlighting the context of its proposed terms in brackets.
Having determined the term requiring construction, the court begins its analysis.
Whereas Fox considers it critical to construe the term to clarify the process of growing low-defect SiC, Cree argues that "[t]he issue in dispute is whether the entirety of the recited regions or seed must meet the density limitations (Cree) or only portions of the regions or seeds (Fox)." Cree's Opening Br. 20. In other words, Cree considers it critical to construe the term so as to explicate that there is only one axial region, it is the SiC crystal grown via the method and apparatus described in the '130 patent, and it must meet the claimed defect densities (e.g., "a density of dislocations of less than 10
Although the claims do not define the term, they provide guidance in formulating its proper construction, and reveal that Cree is incorrect that the patent contemplate only one axial region. All of the disputed claims describe "a silicon carbide material comprising an axial region of recrystallized single crystal silicon carbide." E.g., '130 patent col.8 11.6-7 (emphasis added). When used as a transition phrase, as is the case here, the "usual and generally consistent meaning of . . . `comprising' [is] that the ensuing elements or steps are not limiting." CIAS, Inc. v. Alliance Gaming Corp., 504 F.3d 1356, 1360 (Fed.Cir.2007) ("In the patent claim context the term `comprising' is well understood to mean `including but not limited to.'"). Moreover, the Federal Circuit "has repeatedly emphasized that an indefinite article `a' or `an' in patent parlance carries the meaning `one or more' in open-ended claims containing the transitional phrase `comprising.'" Baldwin Graphic Sys., Inc. v. Siebert, Inc., 512 F.3d 1338, 1342 (Fed.Cir. 2008) (citations omitted). Accordingly, unless an exception to this rule is met, the claims explicitly contemplate one or more axial regions.
"The exceptions to this rule are extremely limited: a patentee must `evince[ ] a clear intent' to limit `a' or `an' to `one.'" Id. (citations omitted). Here, neither "the language of the claims themselves, the specification, [n]or the prosecution history necessitate a departure from the rule." Id. at 1343 (citations omitted). Contrary to Cree's characterization, nothing in the specification indicates that there is only one axial region in each SiC crystal. Cree argues that Figure 1—"a cross-sectional view of [the apparatus in which the SiC material is grown] according to the invention," '130 patent col.3 11.66-67—labels the axial region as a single zone.
This is wrong. Figure 1 and the specification describe the "axial growth zone," not the "axial region," as a single zone. As set forth in the specification, "[a]n axial growth zone 107 is defined by the substantially parallel surfaces of source 101 and seed 103 in combination with sidewalls 109 of crucible 105." Id. col.4 11.13-15. In other words, the "axial growth zone" is the space in the crucible where the SiC material is grown, see id. col.5 11.47-56 (providing that "a stable composition of the vapor phase within growth zone 107 can be achieved" (emphasis added)), but it is not a region within the SiC material. Discussion of the axial growth zone sheds no light
Similarly, it is immaterial that the intrinsic evidence does not indicate that "an axial region" is subdivided for the purposes of measuring the defect densities claimed in the patent. The SiC material can be subdivided into one or more axial regions for the purpose of measuring the defect densities. In other words, the claims contemplate that one axial region in the SiC material may satisfy the claimed defect densities and other axial regions within that same SiC material may not. Indeed, Fox does not dispute that the claims establish that the same axial region must meet all of the claimed defect densities. For the above reasons, the court finds that a person of ordinary skill in the art at the time of the invention would have understood that the patent claims one or more axial regions in the SiC material that meet the claimed defect densities, while allowing for other axial regions in that same SiC material that do not meet those same claimed defect densities.
The ordinary and customary meaning of the phrase "re-crystallized single crystal silicon carbide" is not discoverable through the claims themselves, but the specification resolves the matter. The court agrees with Fox that the specification, read as a whole, clearly describes a method of growing SiC, where source material is heated until it becomes a vapor, which subsequently condenses on the seed to form a SiC crystal. The background of the invention only describes methods for growing SiC that "utilize[e] vapor-phase crystallization of evaporated solid silicon carbide," id. col.1 11.29-30, in which the "growth surface [is on] the SiC seed crystal." Id. col.2 1.17. Furthermore, the description of the invention itself "leads to the inescapable conclusion," Alloc, Inc. v. Int'l Trade Comm'n, 342 F.3d 1361, 1370 (Fed.Cir.2003), that the claimed invention is predicated on a growth method in which source SiC sublimes and then condenses on the seed crystal. See, e.g., '130 patent col.3 ll.2 8-32 (describing the invention as requiring a "evaporating surface" for the source SiC material, "a SiC seed crystal," and a growth surface); id. 11.38-46 (providing that the crucible in which the SiC material is grown is "no longer capable of absorbing SiC vapors as the monocrystalline silicon carbide is grown" (emphasis added)); id. col.5 11.11-14 (describing the process of "evaporation of the SiC of source 101 and vapor phase crystallization of SiC on the growing surface of seed 103").
The court cannot agree, however, that the specification establishes a method directed toward "bulk" growth. Rather, the clear and consistent description of the invention is a method directed toward growth of low defect SiC. See id. col.3 11.10-14 ("[W]hat is needed in the art is a method and system that allows high quality SiC single crystals to be grown. The present invention provides such a method and system."). Although the embodiments certainly indicate that a large crystal can be grown, see id. col.5 11.22-26 and 46-50, this is an insufficient basis from which to read a limitation of "bulk" growth into the claims. See Alloc, 342 F.3d at 1370 ("[T]his court looks to whether the specification refers to a limitation only as a part of less than all possible embodiments or whether the specification read as a whole suggests that the very character of the invention requires the limitation be a part of every embodiment."). Nothing in the specification explicitly contrasts the size of a SiC crystal grown through the method and apparatus described in the '130 patent to SiC crystals grown through other methods. The specification merely provides that examples of "as-grown single crystals were approximately 10 millimeters thick
For the above reasons, the court construes "axial region of re-crystallized single crystal silicon carbide" to mean "portion of a silicon carbide crystal that is grown in a direction substantially perpendicular to the seed crystal plane by heating solid silicon carbide to form a vapor that then condenses onto the seed crystal."
Fox proposes that "density of dislocations," which appears in claims 1, 7, 13, and 19, be construed as one term, and Cree proposes that "density of" and "dislocations" be separately construed.
The court first sets forth the contours of the parties' fundamental disagreement, as it informs how each party approaches the construction of the term "density of dislocations,"
The claims explicitly set forth the unit of measurement for each type of defect. Cree seeks a construction of "a density of" that parallels the applicable unit. In the case of dislocations, the claims set forth a unit of "square centimeter[s]," and so Cree seeks a construction that means "the total length of dislocations per unit volume."
Cree's only support for its construction is scientific articles. Extrinsic evidence is generally viewed as less reliable than intrinsic evidence. See Phillips, 415 F.3d at 1318. The court is most concerned that Cree "naturally [chose] the pieces of extrinsic evidence most favorable to its cause, leaving the court with the considerable task of filtering the useful . . . from the fluff." Id. This filtering process reveals that Cree did just that, as the extrinsic evidence actually supports both its position and Fox's position. See, e.g., Ex. 14 to Borchers Decl. in Supp. of Cree's Opening Br., ECF No. 58-11 (remarking that "[m]any experimental methods are available for estimating dislocation densities, [including] direct counts . . . of dislocation nucleated etch pits on the surface"); Ex. 15 to Borchers Decl. in Supp. of Cree's Opening Br., ECF No. 58-12 ("The density of dislocations is then the number of dislocation lines intersected by a plane of unit area normal to them."). Accordingly, the extrinsic evidence does not support adopting Cree's proposed construction, and the
The term cannot be limited as Fox desires either, as there is no indication that the patent requires limiting the dislocations counted to those crossing the surface of an axial region.
As noted, the parties' disagreement as to the proper technique for measuring defects in an axial region of the as-grown SiC material informs their respective constructions of the density limitations in the claims, including the term "density of micropipes," which appears in claims 1, 7, 13, and 19.
The term "density of secondary phase inclusions" appears in claims 1, 7, 13, and 19. As with the preceding two terms, Fox's proposed construction of the term has "density of" meaning "concentration of." Cree proposes that "density of" and "secondary phase inclusion" be separately construed, and, again, seeks a construction of "density of" that parallels the applicable unit of measurement set forth in the claim language. In the case of secondary phase inclusions, the claims set forth a unit of "cubic centimeter[s]," and so Cree seeks a construction that means "the number of inclusions per unit volume." The parties' arguments in support of their constructions of the phrase "density of" are, again, identical to those offered in regards to the term "density of dislocations," and nothing in the record supports a different construction of that phrase here.
The parties cannot agree on the proper construction of the term "secondary phase inclusions." Fox proposes it means "polytypes different than the polytype of the bulk silicon carbide crystal material and/or precipitates of silicon, carbon, and tantalum or niobium, and their compounds." Cree proposes that the term "inclusion" should be separately defined and mean a "feature in a material not identical to the material matrix." Cree proposes that the term "secondary phase inclusion" means "an inclusion of material other than the primary phase such as other polytypes of silicon carbide, inclusions of carbon, silicon, tantalum or their compounds." Both parties agree that polytypes different than the main polytype of SiC in the SiC crystal constitute a secondary phase inclusion. See '130 patent col.1 ll.49-54. The dispute centers on what else may constitute one. The term's ordinary meaning as understood by a person of skill in the art is not readily apparent, and the claims do not define "secondary phase inclusions." Accordingly, the court must examine the evidence.
The claims do not define the term "secondary phase inclusions," but they provide guidance in formulating its proper construction in two important respects. First, the claims consistently and exclusively refer to "secondary phase inclusions" as a unitary term; there is no separate reference to "inclusions." Accordingly, by parsing the phrase into two, Cree impermissibly reads the claim term outside the context of the claims in which it appears. See Phillips, 415 F.3d at 1313. Moreover, Cree reads it outside the context of the specification, see id., which also refers to "secondary phase inclusions" as a unitary term.
Second, Cree's definition is overbroad because it encompasses explicit limitations set forth in the dependent claims. Dependent claims 2 through 5, 8 through 11, 14 through 17, and 22 through 25 each assert impurity concentrations of either tantalum or niobium "uniformly distributed throughout the re-crystallized single crystal silicon carbide material" for independent claims 1, 7, 13, and 19, respectively. E.g., '130 patent col.8 11.15-17. Since "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," Phillips, 415 F.3d at 1315, the court presumes that the term "secondary phase inclusions" does not encompass tantalum and niobium impurities that are uniformly-distributed throughout the as-grown SiC material. In other
The specification provides further guidance. The background of the invention describes a growth technique in which, "during the early stages of growth, secondary-phase inclusions of tantalum or its compounds were formed." Id. col.2 11.45-47. This reference reveals that tantalum or its compounds can be a secondary phase inclusion. The next sentence provides guidance into the form those materials must exist in to constitute secondary phase inclusions: "An increased concentration of dissolved tantalum in the monocrystalline SiC was also noted." Id. 11.47-49 (emphasis added). As dissolved tantalum in the SiC crystal is references as an additional feature, one can infer that secondary phase inclusion tantalum must be in a solid form that is separate from the crystal. In other words, it must be a "precipitate," as Fox proposes.
The examples detail an as-grown SiC crystal with a "density of secondary-phase inclusions (i.e., carbon and silicon)." Id. col.7 11.52-53 (emphasis added). Accordingly, it is clear that carbon and silicon can each be a secondary phase inclusion. The above findings with respect to the form tantalum must take to be a secondary phase inclusion—a precipitate—suggest that the same is true with respect to silicon and carbon. Moreover, such a construction is consistent with the rest of the claims and specification, which contemplate silicon and carbon either combining to form the desired low-defect SiC material or existing as a defect within said material. Considering that dislocations and micropipes are defects in which lines of SiC atoms are displaced, silicon and carbon individually can only be defects if they exist outside the crystalline structure of the SiC material; in other words, as a precipitate.
Finally, the specification supports including niobium in the court's construction of secondary phase inclusions. Unlike silicon, carbon, and tantalum, there is no explicit reference to niobium as a secondary phase inclusion. However, niobium is the only other element besides those three described in the patent, and there is no basis to exclude it as a possible secondary phase inclusion. Indeed, it is logical to include niobium because the patent contemplates an embodiment of the invention in which the crucible is comprised of a niobium, silicon, and carbon composition, see id. col.3 11.38-60 (describing a crucible "fabricated from tantalum or niobium"); id. col.4 11.59-65; there is potential for
Considering the claims, and reading the specification as "provid[ing] an example of how to practice the invention in a particular case," Phillips, 415 F.3d at 1323, it is appropriate to define "secondary phase inclusions" by reference to precipitates of silicon, carbon, tantalum, and niobium. The patent is clear that any SiC that practices the invention of the '130 patent must be grown through a method and apparatus that employs silicon, carbide, and either tantalum or niobium. See '130 patent col.3 11.28-40 (summarizing the invention as comprised of "a SiC source and a SiC seed crystal" and a "crucible [that] is comprised of tantalum or niobium"). It is inappropriate, however, to limit the term's construction to only those precipitates, as the patent provides that "the present invention may be embodied in other specific forms without departing from the spirit or essential characteristics thereof. Accordingly, the disclosures and descriptions herein are intended to be illustrative, but not limiting, of the scope of the invention which is set forth in the following claims." Id. cols.7 1.66-8 1.4 (emphasis added). In other words, the patentee did not "intend[ ] for the claims and the embodiments in the specification to be strictly coextensive," Phillips, 415 F.3d at 1323, and, therefore, other embodiments of the '130 patent's invention may potentially grow SiC material with precipitates of other materials. For all the above reasons, the court construes the term "density of secondary phase inclusions" to mean "concentration of polytypes different than the polytype of the silicon carbide crystal material and/or precipitates of material such as silicon, carbon, and tantalum or niobium, and their compounds."
The court construes the following terms found in claims 1 and 7:(1) "dislocations," (2) "density of defects," (3) "region of recrystallized silicon carbide,"
The parties agree that the term "dislocations" should be construed here as it is construed in the '130 patent. Accordingly, "dislocations" means "defects where lines of atoms in a crystal structure are displaced, including screw, edge, and basal plane dislocations."
Fox proposes that "density of defects," which appears in claims 1 and 7 be construed as one term, and Cree proposes
Considering Fox's proposed construction, it is clear that the parties dispute the construction of the term "density of defects, said defects comprised of micropipes and dislocations." Once again, the parties' disagreement as to the proper technique for measuring defects in the region of as-grown SiC in question informs their respective proposed constructions of the term "density of."
The parties cannot agree on whether "defects" requires construction. Fox's proposed construction retains the word "defect," but Cree substitutes it with the phrase "irregularities in the silicon carbide." Curiously, though, Cree is satisfied to construe "dislocations" as "defects where lines of atoms in a crystal structure are displaced, including screw, edge, and basal plane dislocations."
The parties agree that the claim language "said defects comprised of micropipes and dislocations" conveys that defects are not limited to micropipes and dislocations, see CIAS, 504 F.3d at 1360, but they nonetheless offer different constructions. In order to resolve the controversy, then, the court need only construe the term to express that point. See U.S. Surgical, 103 F.3d at 1568. According to the Federal Circuit, "the term `comprising' is well understood to mean `including but not limited to.'" CIAS, 504 F.3d at 1360. Accordingly, the court uses that phrasing to communicate that "the claims do not exclude the presence" in the as-grown SiC material of defects "in addition to those explicitly recited." Id. For all the above reasons, the court construes the term "density of defects, said defects comprised of micropipes and dislocations" to mean "concentration of defects, including but not limited to micropipes and dislocations."
Cree also proposes that the terms "said single crystal silicon carbide seed crystal having a first density of defects," which appears in claims 1 and 7, "said axial region having a second density of defects," which appears in claim 1, and "said lateral region having a third density of defects," which also appears in claim 1 be construed. Fox does not believe construction of these terms is necessary. Cree proposes that the term "said single crystal silicon carbide seed crystal having a first density of defects" be construed as "measuring the densities of the defects throughout the entirety of the seed crystal." The meaning Cree seeks is readily apparent from the claim language—the relevant measurement is the density of defects in the single crystal silicon carbide seed, not merely a part of it. See O2 Micro Int'l Ltd. v. Beyond Innovation Tech. Co., 521 F.3d 1351, 1361 (Fed.Cir.2008) (noting that "[a] determination that a claim term `needs no construction' or has the `plain and ordinary meaning' may be inadequate . . . when reliance on a term's `ordinary' meaning does not resolve the parties' dispute" (emphasis added)). The claim language expresses the ordinary and customary meaning that a person ordinarily skilled in the art reading the entirety of the patent would ascribe to it. Accordingly, the term does not require construction.
Similarly, Cree proposes that the other two terms mean "measuring the densities of the defects throughout the entirety of the same [region in question]." Cree's concern is the same one raised with the term "axial region of re-crystallized single crystal silicon carbide" in the '130 patent, as well as that term and the "lateral region" term in the '026 patent: whether the entirety of the recited region must meet the density-limitations or only portions of the regions.
Fox proposes that the term "region of re-crystallized silicon carbide," which appears in claims 1 and 7 be construed, and Cree proposes that the term "[region of] re-crystallized [silicon carbide or single crystal silicon carbide]" be construed.
The parties' proposed constructions and arguments are the same as those raised in regard to the term "axial region of re-crystallized single crystal silicon carbide" in the '130 patent. This is sensible because the '026 specification describes the same method of growing SiC as the '130 patent—source material is heated until it becomes a vapor, which subsequently condenses on the seed to form a SiC crystal. Similar to the '130 patent, the background of the '026 invention describes a method in which "SiC is formed on a bulk single crystal of SiC . . . by chemical vapor deposition." '026 patent col.1 ll.54-59. Also like the '130 patent, the description of the invention establishes that the claimed invention is predicated on a growth method in which source SiC sublimes and then condenses on the seed crystal. See id. col.2 ll.12-13 (describing the invention as "using sublimation techniques"); id. 11.65-67 ("In at least one embodiment, a SiC seed crystal is introduced into a sublimation system. . . ."); id. col.6 ll.49-59 (describing the preferred embodiment of the invention in which "[a] source [] is placed within a growth chamber []," "[s]eed crystal . . . [is] then located within the growth chamber," and "quasi-equilibrium vapor phase conditions [are] maintained"). Indeed, the only difference between the methods in the two patents is that in the '026 patent, "[t]he SiC crystal, grown using sublimation techniques, is divided into two stages of growth"—growth in the axial and lateral directions, and then primarily in the axial direction.
Unlike the '130 patent, though, the '026 patent is directed toward "bulk" growth. Dependent claim 5 describes a SiC material of claim 1 in which both the axial and lateral regions are at least once millimeter thick. Dependent claim 6 describes a SiC material of claim 1 in which both the axial and lateral regions are at least one centimeter thick. Dependent claims 12 and 13 describe the same in regards to SiC material described in claim 7. Considering that the background of the invention provides that "bulk materials [are] materials at least a millimeter thick or more preferably, at least a centimeter thick," id. col.1 ll.65-67, dependent claims 5, 6, 12, and 13 serve as "valuable sources of enlightenment" that the patent contemplates bulk growth. Phillips, 415 F.3d at 1314. Moreover, the specification clearly indicates that the '026 patent's invention is a method directed toward growth of high quality, bulk SiC. See '026 patent col.2 ll.2-7 ("[W]hat is needed in the art is a technique of growing bulk SiC material
For the above reasons, and in light of the court's construction of a parallel term in the '130 patent, the court construes "region of re-crystallized silicon carbide" to mean "portion of a bulk silicon carbide crystal that is grown by heating solid silicon carbide to form a vapor that then condenses onto the seed crystal."
Fox proposes that the term "axial region of re-crystallized silicon carbide," which appears in claim 1 be construed, and Cree proposes that the term "axial region [of re-crystallized silicon carbide], said axial region grown off of [said single crystal silicon carbide seed crystal]" be construed.
The court has already construed the term "region of re-crystallized silicon carbide," so the issue in dispute is the meaning of that phrase in the context of the word "axial" and the phrase "said axial region grown off of said single crystal silicon carbide seed crystal." There is no substantive dispute as to the meaning of "axial," and so the court again adopts Fox's proposed construction and finds that it means "a direction substantially perpendicular to the seed crystal plane."
The parties dispute three aspects of the term. First, Cree argues that there is only one axial region in the SiC crystal grown via the method and apparatus described in the '026 patent, and it must meet the claimed defect densities. The court rejects this construction in construing the parallel term in the '130 patent, and nothing in the '026 patent calls for a different conclusion here. Like the '130 patent, all of the disputed claims in the '026 patent describe "a silicon carbide material comprising an axial region of re-crystallized silicon carbide," which means there are "one or more" axial regions unless the patentee expresses a clear intent to limit it to one.
This is wrong. The specification describes the area Cree references as the "core region," not the "axial region." Discussion of the core region does not clearly establish the patentee's intent to limit "an axial region" to one. Rather, the term "core region" appears to signify the section of as-grown SiC material in which one or more axial regions are found. The court finds that a person of ordinary skill in the art at the time of the invention would have understood that the '026 patent, like the '130 patent, claims one or more axial regions in the SiC material that meet the claimed defect density, while allowing for other axial regions that do not meet it.
The second disputed aspect is the appropriate way to construe the term so as to differentiate an axial region from a lateral region. Fox proposes the language "and having a higher density of defects than the lateral region." Fox's proposed construction captures the fact that the patent contemplates a SiC material in which the claimed defect density of a lateral region is less than the claimed defect density of an axial region, see '026 patent col.10 ll.32-34, but this limitation is expressed in other claim terms. See id. ll.25-26 (describing "said axial region [as] having a second density of defects"); id. ll.28-34 (describing "said lateral region [as] "having a third density of defects . . . wherein said third defect density is . . . less than said second defect density"). Accordingly, the court cannot construe the instant term to again differentiate the axial region from the lateral region on the basis of defect density. See Haemonetics Corp. v. Baxter Healthcare Corp., 607 F.3d 776, 781 (Fed.Cir. 2010) (recognizing that the "notice function [of patent claims] would be undermined. . . if courts construed claims so as to render physical structures and characteristics specifically described in those claims superfluous").
Cree proposes the language "and that excludes the lateral region." Cree's proposed construction captures the fact that an axial region and a lateral region are mutually exclusive, see, e.g., '026 patent
The third disputed aspect of the term is whether the phrase "said axial region grown off of said single crystal silicon carbide seed crystal" should be construed as part of the term. Fox does not construe it, and Cree, despite including the phrase in its proposed term, barely accounts for it in its proposed construction—Cree merely replaces that phrase with the language "and from the seed crystal." The claim language expresses the ordinary and customary meaning that a person ordinarily skilled in the art reading the entirety of the patent would ascribe to it. "Said axial region" merely invokes the antecedent phrase,
For the above reasons, the court construes "axial region of re-crystallized silicon carbide" to mean "portion of a silicon carbide crystal that is grown in a direction substantially perpendicular to the seed crystal plane by heating solid silicon carbide to form a vapor that then condenses onto the seed crystal and that excludes the lateral region."
Fox proposes that the term "axial growth path," which appears in claim 7, be construed, and Cree proposes that the term "first region [of re-crystallized silicon carbide], said first region [of re-crystallized silicon carbide] initiating at said growth surface of [said single crystal silicon carbide seed crystal], wherein a first portion of a crystallization growth front corresponding to said first region [of re-crystallized silicon carbide] follows an axial growth path" be construed.
The parties' dispute corresponds to their dispute over the claim 1 term "axial region of re-crystallized silicon carbide." The court agrees with Cree that "the use of the phrase `axial growth path' to define the
Fox proposes that the term "lateral region," which appears in claim 1, be construed, and Cree proposes that the term "lateral region [of re-crystallized silicon carbide], said lateral region grown off of [said single crystal silicon carbide seed crystal]" be construed.
The court has already construed the term "region of re-crystallized silicon carbide,"
In the second aspect of the parties' dispute, Cree argues at there is only one lateral region in the SiC crystal grown via the method and apparatus described in the '026 patent, and it must meet the claimed defect densities. For the same reasons provided in the court's axial term analysis, the court finds that a person of ordinary skill in the art at the time of the invention would have understood that the '026 patent claims one or more lateral regions in the SiC material that meet the claimed defect densities, while allowing for other lateral regions that do not meet it.
The third disputed aspect of the term is the appropriate way to construe it so as to differentiate a lateral region from an axial region. Fox proposes the language "and located either: outside the narrowest diameter of the crystal in proximity to the seed, or outside the diameter of and having a lower density of defects than the axial region." For the same reasons provided in the court's axial term analysis, the court finds that Fox's proposed construction "and having a lower density of defects than the axial region" is already expressed in other claim terms, and, therefore, the court does not construe the instant term to again differentiate the lateral region from the axial region on the basis of defect density.
Part of Fox's proposed construction generally captures the same meaning as Cree's proposed construction—the lateral region extends outside the diameter of the seed crystal—and it is supported by the claims and the specification. The claims set forth that a lateral region, like an axial region, is grown off of the seed crystal, see id. col.10 ll.24 and 29, and the defect density
The last disputed aspect of the term is whether the phrase "said lateral region grown off of said single crystal silicon carbide seed crystal" should be construed as part of the disputed term. For the same reasons provided in the court's axial term analysis, the phrase is not included in the court's construction here.
For the above reasons, the court construes "lateral region of re-crystallized single crystal silicon carbide" to mean "portion of a silicon carbide crystal that is grown in a direction extending outside the diameter of the seed crystal at an angle of greater than 25 degrees as measured from a normal growth axis by heating solid silicon carbide to form a vapor that then condenses onto the seed crystal and that excludes the axial region."
Fox proposes that the term "laterally expanding growth path," which appears in claim 7, be construed, and Cree proposes that the term "second region [of re-crystallized silicon carbide], said second region [of re-crystallized silicon carbide] initiating at said growth surface of [said single crystal silicon carbide seed crystal], wherein a second portion of said crystallization growth front corresponding to said second region [of re-crystallized silicon carbide] follows a laterally expanding growth path" be construed.
Just as the parties' dispute regarding the claim 7 term "axial growth path" corresponds to their dispute over the claim 1
Cree proposes that the term "wherein an outermost edge of said second crystallization
For the foregoing reasons, the court construes the parties' disputed terms and phrases as follows:
The court
Cf. supra note 17 and accompanying text. This point is self-evident, though, and so Cree's proposed construction is not necessary.