Boston University v. Everlight: Claim Invalid For Lack Of Enablement Because 17% Was “Physically Impossible”

August 10, 2018

Last week, the Federal Circuit issued its opinion in Boston University (BU) v. Everlight, in which the court found that the only asserted claim (claim 19) was invalid for lack of enablement because 1/6 (17%) of the claimed subject matter was “physically impossible.”

Claim 19 was the only claim asserted at trial.  The claim was directed to a semiconductor device comprising a substrate, a non-single crystalline buffer layer, and a growth layer grown on the buffer layer.

The district court interpreted the claim as covering six possibilities: 

(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.

At trial, both experts agreed that the sixth permutation -- a monocrystalline growth layer formed directly on an amorphous buffer layer – was impossible at the time the patent application was filed.  Yet, the claim survived at the district court level as the court determined it was enabled.

The Federal Circuit disagreed, stating that “[w]e can safely conclude that the specification does not enable what the experts agree is physically impossible.”  In reaching its conclusion, the Federal Circuit relied on precedent which “make[s] clear that the specification must enable the full scope of the claimed invention.”   

BU argued that the patent need not enable the sixth permutation because “there is no dispute as to enablement of five out of the six referenced permutations,” and that 83% “is sufficient.”  The Federal Circuit was not persuaded.

Was the Federal Circuit’s opinion too harsh? 

Perhaps.  But perhaps not.  The Federal Circuit noted that BU was responsible for creating the enablement issue, noting:  “to 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 (reciting BU’s proposed construction as ‘a layer of material that is not monocrystalline, located between the first substrate and the first growth layer’  (emphasis added)).  Having obtained a claim construction that included a purely amorphous layer within the scope of the claim, BU then needed to successfully defend against an enablement challenge as to the claim’s full scope.”

So, what are some lessons from the BU case?

1.      If you are a defendant in litigation and an asserted claim covers “impossible” subject matter, consider an enablement attack.  17% physical impossibility was sufficient to render the claim invalid in the BU case.  Perhaps lower levels of impossibility would be sufficient to render a claim invalid as non-enabled, particularly given the Federal Circuit’s reliance on precedent which “make[s] clear that the specification must enable the full scope of the claimed invention.”    

2.      If you are a patentee in litigation, choose your claim construction carefully.  Although broad claim construction is helpful for purposes of proving literal infringement, broad claim construction could make a claim more susceptible to validity attacks not only because more prior art may be available against a broader claim, but also because the breadth of the claim could raise Section 112 issues (written description, enablement) as the BU case demonstrates.