Dual epitaxy CMOS processing using selective nitride formation for reduced gate pitch
A method of forming a complementary metal oxide semiconductor (CMOS) device structure includes forming a spacer layer material over a substrate and over gate structures defined in a first polarity type region and a second polarity type region; selectively etching the spacer layer material in the first polarity type region to form first gate sidewall spacers; forming first epitaxially grown source/drain (SD) regions in the first polarity type region; selectively forming a protection layer only on exposed surfaces of the first SD regions, so as not to increase a thickness of the spacer layer material in the second polarity type region; forming a masking layer over the first polarity type region, and etching the spacer layer material in the second polarity type region to form second gate sidewall spacers; and removing the masking layer and forming second epitaxially grown SD regions in the second polarity type region.
1. A complementary metal oxide semiconductor (CMOS) device, comprising:
a substrate;
gate structures formed in both a first polarity type region and a second polarity type region of the substrate, the gate structures having sidewall spacers adjacent thereto;
first epitaxially grown source/drain (SD) regions formed in the first polarity type region;
a protection layer selectively formed only on surfaces of the first epitaxially grown SD regions, the protection layer being excluded from upper surfaces of the gate structures located in the first epitaxially grown SD regions;
second epitaxially grown SD regions formed in the second polarity type region; and
first and second electrically conductive SD contacts, an end of the first electrically conductive SD contacts formed on an upper surface of the first epitaxially grown SD regions and an end of the second electrically conductive SD contacts formed on an upper surface of the second epitaxially grown SD regions,
wherein a portion of the first electrically conductive SD contacts are surrounded by the protection layer.
2. The device of claim 1 , wherein the selectively formed protection layer only on exposed surfaces of the first epitaxially grown SD regions comprises a gas cluster ion beam (GCIB) nitride layer.
3. The device of claim 1 , wherein the sidewall spacers comprise a low-k material.
4. The device of claim 1 , wherein adjacent gate structures have a pitch spacing of about 45 nanometers (nm).
5. The device of claim 4 , wherein the nitride material is formed at a thickness of about 9 nm such that an opening between adjacent gate structures is about 12 nm.