It is black-letter law that a claim must be enabled throughout its full scope in order to satisfy the enablement requirement of 35 U.S.C. § 112(a); see, e.g., Liebel-Flarsheim Co. v. Medrad, Inc., 481 F.3d 1371, 1378–79 (Fed. Cir. 2007).  And in the Federal Circuit's recent decision in Trustees of Boston University v. Everlight Electronics Co., violation of this rubric invalidated Boston University's claims.

The claims were directed to light-emitting diodes (LEDs) as disclosed in U.S. Patent No. 5,686,738; claim 19 was the only claim at issue:

A semiconductor device comprising:
    a substrate, said substrate consisting of a material selected from the group consisting of (100) silicon, (111) silicon, (0001) sapphire, (11–20) sapphire, (1–102) sapphire, (111) gallium aresenide, (100) gallium aresenide, magnesium oxide, zinc oxide and silicon carbide;
    a non-single crystalline buffer layer, comprising a first material grown on said substrate, the first material consisting essentially of gallium nitride; and
    a growth layer grown on the buffer layer, the growth layer comprising gallium nitride and a first dopant material.

(where the italicized claim terms were relevant to the District Court's decision below and the Federal Circuit's contrary decision in its opinion).  As explained in the opinion, LEDs are conventionally made comprising several layers, which include a substrate, an "n-type" semiconductor layer and a "p-type" semiconductor layer.  As solid-state materials, these layers are either monocrystalline, polycrystalline, or amorphous (which can include species comprising a mixture of amorphous and polycrystalline types).  Finally, a particular method of producing semiconductor layers is termed epitaxy, which comprises depositing successive semiconductor material in such a way that the newly added material "mimics the substrate's crystal lattice structure" as the semiconductor layer grows.  One particular semiconductor material is gallium nitride (GaN) that emits blue light in response to passage of an electric current.

The '738 patent describes a method for producing GaN semiconductors using a form of epitaxy termed molecular beam epitaxy, which is "a two step process comprising a low temperature nucleation step and a high temperature growth step."  This produces a first buffer layer of amorphous GaN when heated in the second step to "crystallize the amorphous layer."  This permits monocrystalline GaN to be grown on the crystallized substrate layer.

The District Court construed the term "grown on" to mean "formed indirectly or directly above," and construed the term "a non-single crystalline buffer layer" to mean "a layer of material that is not monocrystalline," i.e., one that is polycrystalline, amorphous, or a mixture of amorphous and polycrystalline, and that is "located between the first substrate and the first growth layer."  The parties' disagreement, and the Federal Circuit's opinion, concerned construction of the term "grown on."

As set forth in the opinion:

Assuming a monocrystalline growth layer, together these constructions raise six permutations for the relationship between claim 19's growth layer and buffer layer: (1) monocrystalline growth layer formed indirectly on a polycrystalline buffer layer; (2) monocrystalline growth layer formed indirectly on a buffer layer that is a mixture of polycrystalline and amorphous; (3) monocrystalline growth layer formed indirectly on an amorphous buffer layer; (4) monocrystalline growth layer formed directly on a polycrystalline buffer layer; (5) monocrystalline growth layer formed directly on a buffer layer that is a mixture of polycrystalline and amorphous; and (6) monocrystalline growth layer formed directly on an amorphous buffer layer [emphasis in opinion].

Defendants were found by a jury to infringe claim 19 and that they had not established that the claim was invalid.  The District Court denied Defendants' motion for judgment as a matter of law (JMOL) based on nonenablement under 35 U.S.C. § 112(a), holding that the specification did not need to enable producing a monocrystalline growth layer directly on an amorphous substrate, and that it disclosed producing such a monocrystalline growth layer indirectly on the amorphous substrate.  Both parties appealed.

The Federal Circuit reversed, finding claim 19 to be invalid for nonenablement, in an opinion by Chief Judge Prost joined by Judges Moore and Reyna.  "The enablement issue in this case concerns this sixth permutation—a monocrystalline growth layer formed directly on an amorphous buffer layer," according to the opinion, and whether the specification provided an enabling disclosure for producing a monocrystalline growth layer formed directly on an amorphous buffer layer.  The panel held that it did not, a conclusion supported by testimony from Defendants' expert that it was "[physically] impossible to epitaxially grow a monocrystalline film directly on an amorphous structure"; patentee's expert did not disagree.  (Boston University also contended that the specification did not disclose epitaxial growth, but the panel rejected this argument based, inter alia, on the "saturated" repetition of the word "epitaxy" in the short, four-column specification.)  The Federal Circuit also rejected argument that others, including the inventor, had grown a monocrystalline layer directly on an amorphous substrate, because:

[T]he inquiry is not whether it was, or is, possible to make the full scope of the claimed device—a scope that here covers a monocrystalline growth layer directly on an amorphous layer.  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.  Viewed in this light, BU's evidence is not probative of enablement.  BU does not even suggest that these results were accomplished by following the specification's teachings, or that achieving these results was within an ordinary artisan's skill as of the patent's effective filing date.

(citing Enzo Biochem, Inc. v. Calgene, Inc., 188 F.3d 1362, 1376 (Fed. Cir. 1999)).

As has been the case in other precedent, this decision does not vitiate the "supplemental" effects on a disclosure provided by knowledge of one skilled in the art or routine experimentation and does not stand for the proposition that a patentee "must expressly spell out every possible iteration of every claim."  See Genentech, Inc. v. Novo Nordisk A/S, 108 F.3d 1361, 1365 (Fed. Cir. 1997), and Sitrick v. Dreamworks, LLC, 516 F.3d 993, 1000 (Fed. Cir. 2008).  But "epitaxially growing a monocrystalline layer directly on an amorphous layer would have required undue experimentation" (being that the expert testimony established it would have been impossible at the time the invention was made) and the specification contained no teachings purporting to show such growth could be achieved according to the invention.

The opinion notes in closing that what occurred here is not uncommon:

[T]o some extent, BU created its own enablement problem.  BU sought a construction of "a non-single crystalline buffer layer" that included a purely amorphous layer.  Having obtained a claim construction that included a purely amorphous layer within the scope of the claim [presumably to provide a basis for its infringement allegations], BU then needed to successfully defend against an enablement challenge as to the claim's full scope [citations to the record omitted].

Trustees of Boston University v. Everlight Electronics Co. (Fed. Cir. 2018)
Panel: Chief Judge Prost and Circuit Judges Moore and Reyna
Opinion by Chief Judge Prost