October, 2nd, 2018

By Georgi Korobanov

Recently the Court of Appeals for the Federal Circuit reversed a lower court’s denial of a motion for judgment as a matter of law that challenged the validity of asserted U.S. Patent No. 5,686,738. In Trustees of Boston University (BU) v. Everlight Electronics Co., the three-judge panel found that the asserted claim was not enabled.

The asserted claim, directed to a semiconductor, required:

“…a non-single crystalline buffer layer, …; and

a growth layer grown on the buffer layer…”

BU sought a claim construction of “a non-single crystalline buffer layer” and “grown on” and then needed to defend against an enablement challenge as to the claim’s scope. The enablement issue concerned a single interpretation of the construction — a monocrystalline growth layer formed directly on the buffer layer wherein the buffer layer was amorphous.

A patent’s specification must “contain a written description of the 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.” 35 U.S.C. § 112 para. 1 (Replaced by § 112(a) in the AIA)

On appeal, Everlight focused its enablement argument on whether a person of ordinary skill in the art could practice the invention with a monocrystalline growth layer formed directly on an amorphous buffer layer at the time of the invention. During oral arguments, BU’s expert agreed that it is impossible to epitaxially grow a monocrystalline film directly on an amorphous structure. Although epitaxy was not required, the only fabrication technique discussed in the patent was “epitaxy”. BU’s only argument was that others had successfully grown a monocrystalline layer on top of an amorphous buffer layer using other methods and therefore a method of fabrication did not have to be expressly disclosed. However, the enablement inquiry is not whether it was, or is, possible to make the full scope of the claimed device years after the patent’s effective filing date, 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. Not being able to point to any other methods in the disclosure doomed BU’s arguments.

The application claimed priority to an application filed in 1991. Although the inventor, later in his career, might well have been able to form a monocrystalline growth layer directly on an amorphous buffer layer, no evidence was presented how this was possible or known to the inventor in 1991.

Practice Tip: When drafting claims or arguing claim construction, review all claim terms based on the broadest reasonable interpretation and on ordinary and customary meanings as understood by one of ordinary skill in the art to make sure the specification contains support for every limitation of the claim to avoid enablement issues.


WHIPgroup is leading counsel for U.S. and international technology companies. We specialize in patent and trademark law.

© 2018 Whitmyer IP Group, Stamford, Connecticut.

© Copyright 2024 Whitmyer IP Group