Appeal No. 2000-1587
Application 09/055,254
the remaining oxide layer and the hard mask (specification,
pages 5 & 6).
The only independent claim is reproduced as follows:
1. A method for forming shallow trench isolation in a
silicon substrate, comprising the steps of:
a. forming a hard mask over said silicon substrate;
b. defining said hard mask and forming a shallow trench
by etching;
c. forming an oxide layer to fill said shallow trench
and over said hard mask, in which the oxide layer over said
hard mask which has smaller area is thinner and the oxide
layer over said hard mask which has larger area is thicker;
d. coating a layer of spin-on-glass with suitable
thickness control and performing low-temperature baking;
e. partially etching back said spin-on-glass and oxide
layer to remove the part outside the shallow trench, wherein
said partial etching-back is performed with the recipe whose
etching rate to said oxide is higher than that of spin-on-
glass;
f. curing said spin-on-glass of which a residue
partially remaining over the shallow trench in the larger area
serves as a protection mask; and
g. etching back the remaining of said oxide and said
spin-on-glass over the hard mask to remove it and taking said
hard mask as the end point of etching.
3
Page: Previous 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 Next
Last modified: November 3, 2007