Appeal No. 1998-2938
Application 08/510,752
lattice constant and neither suggests a mix-and-match
approach. As to the reasoning based on equivalence of the
materials, Zucker teaches that different material systems
could be used to produce a strained quantum well consistent
with the teachings in Zucker, not in all quantum wells no
matter how they are made. Further, Zucker discloses that the
strain introduced by the lattice mismatch controls the
resulting optical and electrooptical properties (col. 5,
lines 32-37). This makes it questionable whether introducing
strain in the non-uniform composition layers of Ishikawa would
work. For these reasons, we conclude that the Examiner has
failed to show the motivation necessary to establish a prima
facie case of obviousness as to the limitation of a quantum
well substructure that "has a non-uniform composition that
provides, across the thickness of the layer, a non-uniform
value of lattice constant to produce a strain profile."
It is not clear why the Examiner has gone to the trouble
of trying to combine Ishikawa with Zucker to show a quantum
well substructure with a non-uniform value of lattice constant
when such a substructure is admitted to be known. In the
Background to the Invention it is stated (specification, p. 2,
- 8 -
Page: Previous 1 2 3 4 5 6 7 8 9 10 11 12 13 14 Next
Last modified: November 3, 2007