Comprehensive ballistic saturation current study of strained germanium NMOSFETs

The ballistic saturation drain current in strained germanium NMOSFET is assessed using an analytical model. The angular dependence of ballistic saturation drain current in Ge NMOSFET for all substrate orientation under different strain conditions is investigated. Applying biaxial tensile stress on (111) wafer with [-110] channel direction can reach the highest ballistic saturation drain current. For both tensile and compressive strain, ballistic saturation drain current enhancement can be found for all wafer orientation if strain condition and channel direction are optimized.