Appeal 2007-3417
Application 10/351,739
In terms of structure, claim 1 is directed to a silicon single crystal
having a <113> orientation comprising an ingot having two conical end
pieces, one of the end pieces being connected to a dash seed of at most 70
mm length. The claim further recites that the single crystal is produced
using the Czochralski method.
Aydelott describes a single crystal silicon. The difference is that
Aydelott does not specifically discuss the orientations which can be grown
and has a more general disclosure of dash seed length. However, we
determine that, based on the scope and content of the prior art as well as the
level of skill in the art evidenced by the references, the evidence supports the
Examiner’s conclusion of obviousness.
According to Aydelott:
The monocrystalline silicon that is the starting material
for many semiconductor electronic components is commonly
prepared by a Czochralski (CZ) process. In this process, pieces
of polycrystalline silicon are placed in a crucible and melted to
a liquidous state, thereby creating a melt. A seed crystal having
the desired monocrystalline atomic structure is then lowered
into contact with the molten silicon. As the seed crystal is
slowly extracted from the melt, a monocrystalline crystal is
drawn from the melt having the same atomic structure as the
seed crystal. (Aydelott, col. 1, ll. 17-26 (emphasis added)).
This portion of Aydelott suggests that the orientation of the end-
product single crystal is dependent on the orientation of the seed used to
make the single crystal. According to Appellants’ Specification, the <113>
orientation was “among the silicon crystal orientations which have been
researched most thoroughly.” (Specification 1:7-9). This is evidence that the
<113> orientation for silicon was known in the art. Given that the <113>
4
Page: Previous 1 2 3 4 5 6 7 Next
Last modified: September 9, 2013