Introduction
In its July 25, 2018 decision in Trustees of Boston University (BU) v. Everlight Electronics Co., Ltd., et al., the Court of Appeals for the Federal Circuit found that claim 19 in U.S. patent No. 5,686,738 did not satisfy the enablement requirement of 35 U.S.C. § 112 resulting in invalidation of the claim. In finding for the defendants, the court reversed the district court’s denial of defendant’s motion for JMOL that claim 19 was invalid on lack of enablement grounds.
Background
Under § 112, the patent’s specification must contain “a written description of and invention, and of the manner and process of making and using it, in such full, clear, concise, and exact terms as to enable any person skilled in the art to which it pertains . . .to make and use the same.” The test for enablement is whether the “specification teaches those skilled in the art hot to make and use the full scope of the claimed invention without “undue experimentation.”
The commentator previously blogged about the importance of the written description in claim evaluation. That requirement focuses on the adequacy of the disclosure for establishing a link between a claimed element and what the specification discloses. Although closely related to the written description requirement, the enablement requirement focuses more on whether the specification sufficiently disclose details on how to make and practice the invention.
The Case
The subject matter of the ‘738 patent involved LED semiconductor devices. LEDs typically consist of multiple layers – a substrate, and two different types of semiconductor layer. . The layers are solid-state materials having one of three types of crystal lattice structures: monocrystalline, polycrystalline, or a mixture of polycrystalline and amorphous regions. Solid-state materials can also just be amorphous.
Semiconductors are fabricated by a process known as epitaxy. The process involves first depositing molecules of a semi-conductor on a substrate. A successful epitaxy process occurs when the lattice structure of the substrate and the deposited semiconductor layer are the same. Any lattice mismatch can create defects in the deposited semiconductor.
Gallium nitride (GaN) is a semiconductor that emits blue light in LEDs. Fabrication of semiconductors using GaN had proven difficult prior to the filing BU’s patent application. The ‘738 patent addressed this difficulty with a two-step epitaxy-induced growth process comprising a: 1) low temperature nucleation step and; 2) a high temperature growth step. At the lower temperature, the substrate is exposed to gallium and nitrogen, resulting in an amorphous film of GaN defined as the “buffer layer” growing on the substrate. An amorphous solid does not have a definite geometric or crystalline shape and is any noncrystalline solid in which the atoms and molecules are not organized in a definite lattice pattern.
The subsequently introduced higher temperature causes the amorphous GaN buffer layer to crystalize, thereby allowing monocrystalline GaN to be grown on the now crystallized buffer layer without lattice mismatch. Basically, the process is one in which the substrate is pre-conditioned to create a surface onto which monocrystalline GaN could be successfully deposited.
As often happens with patent validity claim disputes, the district court had to construe the meaning of two relevant terms (i.e., engage on claim construction) in what was a relatively simply-worded Claim 19: A semiconductor device comprising a substrate . . . ; a non-single crystalline buffer layer, comprising a first material grown on said substrate; and a growth layer grown on the buffer layer . . . . The district court construed “grown on” to mean formed indirectly or directly above. This construction meant that the growth layer and the buffer layers do not have to be in direct contact and could be separated by intervening layers.
The district court construed “a non-single crystalline buffer layer to mean a layer of material that is not monocrystalline, namely (1) polycrystalline, (2) amorphous, or (3) a mixture of polycrystalline and amorphous located between the first substrate and the first growth layer. This claim construction resulted in six possible permutations involving claim 19’s growth layer and buffer layer.
The enablement issue focused on only one permutation: a monocrystalline growth layer formed directly on an amorphous buffer layer. Here, the Defendants, upon appeal of the jury decision finding infringement to the Federal Circuit, argued that claim 19 is not enabled because it does not teach one skilled in the art how to make the claimed semiconductor device with a monocrystalline growth layer directly on an amorphous buffer layer. In arguing against claim 19, the Defendants asserted that the specification teaches only epitaxy as the method for growing a monocrystalline film directly on an amorphous structure. And, according to the Defendants’ expert witness, it was impossible to epitaxially grow a monocrystalline film directly on an amorphous structure at the time the patent application was filed. The district court had also noted that “[i]t is less clear whether the patent teaches how to grow a monocrystalline GaN layer directly on an amorphous buffer layer, with no intervening layers.”
Unfortunately for BU, the concise patent specification repeatedly focused on epitaxy and variants of the epitaxy. The abstract even used the word epitaxy. A non-epitaxy method was not referenced or otherwise disclosed. BU argued that the ‘738 patent does not teach epitaxy as applied to permutation 6 because epitaxy involves a crystalline layer on top of a crystalline layer. Applying a crystalline layer on top of an amorphous structure does not meet the definition of epitaxy. The Federal Circuit discounted this argument.
Nor did the ‘738 patent include any non-epitaxial teaching in the specification. Had that teaching been included, claim 19 may well have met the enablement requirement.
The testimony of the inventor himself also never described a monoycrystalline growth layer on an amorphous buffer layer without also mentioning some level of crystallinity already present in the buffer layer. Therefore the amorphous buffer layer was apparently not truly crystalline-free; some level of crystalline structure was present to serve as a “seed” for the growth of the monocrystalline growth layer via the epitaxy process.
Additional testimony, now given many years after the ‘738 patent application was filed, showed that a monocrystalline layer could be directly grown on an amorphous buffer layer. The Federal Circuit declined to rely on this fact by pointing out the following: “[t]he inquiry is not whether it was or is possible to make the full scope of the claimed device. The inquiry is whether the patent’s specification taught one of skill in the art how to make such a device without undue experimentation as of the patent’s effective filing date.”
BU may have prevailed had it been it able to establish that the results were accomplished by following the specification’s teaching or that achieving these results was within an ordinary artisan’s skill as of the patent’s effective filing date. As the Court pointed out, the enablement requirement is not met by simply observing that it could be done and making a claim thereto.
Nor did the Federal Circuit buy BU’s argument that the ‘738 patent need not enable the claimed device with a monocrystalline growth layer directly on an amorphous buffer layer because there was no enablement dispute over the other five permutations. The Court emphasized that “its precedents make clear that the specification must enable the full scope of the claimed invention. . . .The scope of the claims must be less than or equal to the scope of the enablement.”
The Court further emphasized that the specification need not disclose what is already well known in the art because “the artisan’s knowledge of the prior art and routine experimentation can often fill gaps, interpolate between embodiments, and perhaps even extrapolate beyond disclosed embodiments, depending upon the predictability of the art.” However, here where epitaxy had not been previously successfully applied to growing a microcrystalline layer on a truly amorphous buffer, more disclosure was clearly required.
The opinion closes with a warning about claim construction: Understand the ramifications of what you wish for. BU sought a construction of a “non-single crystalline buffer layer” that included a purely amorphous layer. This construction was sought for infringement purposes, i.e., to use this claim construction to establish that BU had the right to exclude the defendants from practicing claim 19. By choosing this construction, BU had to defend itself against defendants’ enablement challenge. According to the Federal Circuit, the defendants had proven their case with clear and convincing evidence that claim 19 was not enabled by the specification as of the effective filing date of the patent application.
Some Points to Ponder
Despite the fact that a jury determined that various Defendants infringed claim 19, the Defendants ultimately prevailed because claim 19 was not enabled by the specification. BU’s application had been filed in 1995 and granted in 1997 or about fifteen years (15) before its lawsuit for infringement was brought in the District Court for the District of Massachusetts. By then the technology had surpassed what had been an improvement in the LED manufacturing process at the time BU’s patent application was filed. This case illustrates how technology advances can make an otherwise sound patent obsolete.
It also demonstrates that patent enablement requirements intersect with claim validity requirements. This does not mean that the applicant/inventor need conduct extensive research/optimization testing to obtain a patent. What it does mean is the specification include sufficient information given the state of the prior art and the technical area’s predictability to teach the public how to make and use the invention without undue experimentation. As the BU Court stated, “[t]at is part of the quid pro quo of the patent bargain.”
The case also shows the importance of definitions in the disclosure. The amorphous buffer layer used to practice BU’s invention was not truly amorphous but had some level of crystallinity according to the inventor. This layer was really an amorphous buffer-crystalline hybrid. Had BU been able to show that the amorphous GaN buffer layer was just that (i.e., devoid of crystalline structure) at the time the inventor’s experimentation was done, then its infringement win in the lower court may well have been upheld.
The Bottom Line: Make sure that any specification sufficiently describes the invention and its various embodiments and elements to meet the written description requirement. Then ensure that the invention, as disclosed and claimed, can be practiced. Match each and every claim against the specification to verify that it will pass muster under both specification requirements.
© 2018 by Troy & Schwartz, LLC
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