Comparative study of self-aligned and nonself-aligned SiGe p-metal-oxide-semiconductor modulation-doped field effect transistors with nanometer gate lengths

Self and nonself aligned SiGe p-metal-oxide-semiconductor modulation-doped field effect transistors fabrication processes were compared. The self aligned devices were found exhibiting higher extrinsic transconductances, lower threshold voltages, higher unity current gain cutoff frequencies, and maximum oscillation frequencies compared to nonself-aligned devices.