Appeal No. 95-5110
Application 07/918,954
Independent claim 7 is reproduced as follows:
7. A field effect transistor comprising:
a substrate of a first conductivity type being a drain region;
a first layer of the first conductivity type formed on the
substrate and having a doping level less than that of the
substrate;
a second layer of the first conductivity type formed on the
first layer and having a doping level about 50% of that of the first
layer;
a trench defined in only the second layer and extending to within
about 0.5 Fm of the first layer, the trench being at least
partially filled with a conductive gate electrode;
a source region of the first conductivity type formed in the
second layer and extending to a principal surface of the second
layer and lying adjacent to the sidewalls of the trench; and
a body region of a second conductivity type extending from the
principal surface of the second layer down to and into at least an
upper portion of the first layer and being spaced apart from the
lower portion of the trench, wherein two portions of the body
region lying respectively on two sides of the trench define a
lateral extent of the second layer.
The references relied on by the Examiner are as follows:
Katou (Japan) 56-58267 May 21, 1981
Tsuzuki et al. (Japan) 62-176168 Aug. 01, 1987
Claims 2 through 4, 7 and 10 through 12 stand rejected
under 35 U.S.C. § 103 as being unpatentable over Tsuzuki and
Katou.
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