This letter reports on Ni germanosilicide formation on recessed Si 0.82Ge0.18 source/drain structures and its effects on channel strain. A combination of transmission electron microscopy techniques, including nanobeam diffraction, shed some light on a previously unrecognized factor in the channel strain evolution during silicidation: a Ge accumulation layer produced at the bottom of the germanosilicide layer. The formation of such a Ge rich layer added an additional compressive strain to the channel strain upon moderate silicidation, while the contribution of thermal strain arising from the cooling cycle became dominant in an excessively silicided sample, which turned the channel strain into a tensile value.
Bibliographical noteFunding Information:
This work was financially supported by the “Next generation Substrate technology for high performance semiconductor devices (Grant No. KI002083)” of MKE and “System IC 2010” project of the Korea Ministry of Science and Technology and Ministry of Commerce, Industry and Energy, and acknowledges Hynix Semiconductor, Inc. for assistance with gate patterned wafer preparation.
All Science Journal Classification (ASJC) codes
- Physics and Astronomy (miscellaneous)