Appeal No. 2004-0216
Application No. 09/460,112
c. forming a silicon oxynitride layer on said silicon
nitride layer;
d. forming a photoresist mask over said silicon oxynitride
layer; said photoresist mask having an opening;
e. etching a trench in said silicon oxynitride layer, said
silicon nitride layer, said pad oxide layer and said substrate
through said opening in said photoresist mask;
f. removing said photoresist mask;
g. removing said silicon oxynitride layer;
h. cleaning said substrate with a solution comprising
NH4OH, H2O, and H2O2, wherein water spots are prevented by the
absence of silicon oxynitride;
i. growing a thin silicon oxide layer and depositing a
silicon oxide layer in said trench; and
j. planarizing said silicon oxide layer to form a shallow
trench isolation.
The examiner relies upon the following references as
evidence of obviousness:
Cheng et al. (Cheng) 6,001,704 Dec. 14, 1999
Chau et al. (Chau) 6,087,236 Jul. 11, 2000
Wu 6,020,230 Feb. 01, 2000
Fulford, Jr. et al. (Fulford) 6,051,510 Apr. 18, 2000
Appellants' claimed invention is directed to a method for
forming a shallow trench isolation (STI) using a silicon
oxynitride (SiON) anti-reflective coating (ARC). The method
entails removing the SiON layer before cleaning the substrate
with a solution comprising NH4OH, H2O and H2O2. According to
appellants, they have found that the SiON layer reacts with the
-2-
Page: Previous 1 2 3 4 5 6 Next
Last modified: November 3, 2007