Appeal No. 2001-2659
Application 08/919,674
layer of the first region as required by the appellant’s claims 1
and 2. The first polysilicon layer in the second region is not
removed in this step because the first polysilicon layer is used
as a buffer layer for preventing the semiconductor substrate
surface from being contaminated or damaged when a subsequently-
applied interlayer insulating film (6) is etched from the second
region (col. 6, lines 1-5). Kume’s first polysilicon layer is
not removed until after carrying out the next step in the
appellant’s method, i.e., “sequentially forming a second gate
insulating layer having three insulating layers and a second
polysilicon layer over the entire surface of said first and said
second region”.3 Thus, Kume’s interlayer insulating film (6) and
second polycrystalline layer (7) are formed in the second region
on the first polysilicon layer (5) (figure 1B), whereas the
appellant’s second gate insulating layer (8) and second
polysilicon layer (9) are formed in the second region on the
first gate insulating layer (3) (figure 1B).
3 Kume forms on the first polysilicon layer an interlayer
insulating film (6) and then a second polycrystalline layer (7)
(col. 5, lines 59-64; figure 1B), and then removes the second
polycrystalline layer, the interlayer insulating film and the
first polysilicon layer from the second region (col. 5, lines 65-
68; figure 1C).
5
Page: Previous 1 2 3 4 5 6 7 8 9 10 11 12 Next
Last modified: November 3, 2007