SEMICONDUCTOR DEVICE
A sidewall spacer structure is formed adjacent to a gate structure whereby a material forming an outer surface of the sidewall spacer structure contains nitrogen. Subsequent to its formation the sidewall spacer structure is annealed to harden the sidewall spacer structure from a subsequent cleaning process. An epitaxial layer is formed subsequent to the cleaning process.
1 . A device comprising:
a conductive gate of a transistor overlying a semiconductor substrate;
a sidewall spacer structure abutting the conductive gate, the sidewall spacer structure comprising a first sidewall spacer and a second sidewall spacer between the first sidewall spacer and the conductive gate;
a source/drain extension region underlying the second sidewall spacer;
a deep source/drain region underlying the first sidewall spacer; and
an epitaxial layer abutting the outer surface of the sidewall spacer structure.
2 . The device of claim 1 wherein the first sidewall spacer comprises a first offset spacer and a first liner layer, the first liner layer underlying and abutting the first offset spacer, and wherein the second sidewall spacer comprises a second offset spacer between the first liner layer and the conductive gate.
3 . The device of claim 2 wherein the first liner layer contains an oxide selectively etchable from the first offset layer.
4 . The device of claim 3 wherein the first offset spacer contains nitrogen.
5 . The device of claim 3 wherein the first liner layer of the first sidewall spacer contains a silicon oxynitride.
6 . The device of claim 5 further comprising an epitaxial layer overlying the conductive gate structure.
7 . The device of claim 5 further comprises a silicide at the epitaxial layer.
8 . The device of claim 2 , wherein the second sidewall spacer further comprises a second liner layer between the second offset spacer and the conductive gate.
9 . The device of claim 1 , wherein the material forming an outer surface of the sidewall spacer contains nitrogen.
10 . The device of claim 9 wherein the material forming the outer surface contains a silicon oxynitride.
11 . The device of claim 10 further comprising an epitaxial layer overlying the conductive gate structure.
12 . The device of claim 10 further comprises a silicide at the epitaxial layer.
13 . The device of claim 1 further comprises a silicide at the epitaxial layer.
14 . The device of claim 1 further comprising an epitaxial layer overlying the conductive gate structure.