Appeal No. 2006-1176
Application No. 09/926,202
APPEALED SUBJECT MATTER
The subject matter on appeal is directed to a process for
forming an epitaxial semiconductor wafer having internal
microdefects, without causing external microdefects in a device
formation region (the vicinity of a top surface) of the wafer.
See the specification, pages 1-4. The internal microdefects
“work as gettering sites that capture heavy metal impurities and
others by an action of a so-called internal gettering (IG).” See
the specification, pages 1-2. Details of this process are
recited in representative claims 6 and 102 which are reproduced
below:
6. A manufacturing process for a silicon epitaxial wafer
comprising the steps of:
forming an epitaxial layer on a silicon substrate with
an interstitial oxygen concentration in a range of from
4 x 1017/cm3 to 10 x 1017/cm3 at a temperature of 1000_ C or
higher to obtain a silicon epitaxial wafer; and
applying heat treatment to the silicon epitaxial wafer
at a temperature in a range of from 450_ C to 750_ C;
thereby forming new oxygen precipitation nuclei and
increasing bulk defect density, without reducing internal
gettering.
10. The manufacturing process for a silicon epitaxial wafer
2 For purposes of this appeal, we limit our discussion to
specifically argued claims 6 and 10 consistent with 37 CFR
_ 41.37(c)(1)(vii)(2004).
2
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