Enhanced performance in surface-channel strained-Si n- and p-MOSFETs

Performance enhancements in strained-Si MOSFETs are described. Due to the splitting of the degeneracy in the conduction and valence bands, carrier transport in strained Si is enhanced. Epitaxial growth of Si-based heterostructures was used to fabricate surface-channel strained-Si n- and p-MOSFETs with biaxial tensile strain in the Si channel layer. A significant increase in MOSFET mobility was observed for both electrons and holes in strained-Si devices, consistent with theoretical predictions. The transconductance and current drive of deep submicron strained-Si n-MOSFETs were also enhanced by strain. Device simulations and a simple physical analysis indicate that in addition to the increased low field mobility, enhanced high field transport in strained Si contributes to the observed improvement in device characteristics.