Ge content dependence of radiation damage in Si1‐xGex source/drain p‐type metal oxide semiconductor field effect transistors

Abstract

AbstractThe 2‐MeV electron radiation damage of Si1‐xGex source/drain (S/D) p‐type metal oxide semiconductor field effect transistors (p‐MOSFETs) with different Ge contents is studied. Before electron irradiation, an enhancement of the hole mobility with Ge content of the S/D stressors is clearly observed. On the other hand, after electron irradiation, the drain current and the maximum hole mobility decreases with increasing electron fluence for all Ge contents, because of lattice defects are introduced by the electron irradiation in the Si channel. The threshold voltage shifts and the maximum hole mobility degradation is independent on the Ge content for all electron fluences. These results indicate that the strain‐induced hole mobility enhancement due to Ge doping is retained after electron irradiation in the studied device structure. This indicates that the compressive strain is maintained in the channel. (© 2013 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)