Hot-carrier effects in strained n-channel transistor with silicon-carbon (Si1-yCy) source/drain stressors and its orientation dependence

We report the hot-carrier effects in a novel strained n-channel transistor (n-FET) featuring silicon-carbon source and drain (Si1-yCy S/D) stressors, and its dependence on channel orientations for the first time. Due to strain-induced bandgap reduction, Si1-y C-y S/D n-FETs show enhanced impact ionization and therefore more pronounced drive current degradation over a control n-FET. As a consequence of the increased interface state generation, a strained n-FET with [010] channel shows worse hot-carrier reliability over a transistor with the conventional [110] channel, which leads to a larger shift in threshold voltage and subthreshold swing. In addition, a hot-carrier lifetime projection shows a dependence of operating drain voltage on the channel orientation of the strained n-FET.