Strain relieved SiGe buffers for Si-based heterostructures field-effect transistors

摘要

The transport properties of strained and relaxed Si_1-xGe_x alloys have been investigagted foir x=0...1 by using n-type and p-type modulation doped field-effect transistor (MODFET) structures grown by MBE on to of srain relieved graded buffers. The mobility in slightly n-doped strain relaxed layers is mainly affected by alloy scattering. The electron mobility at a doping concentration of N_de=1×10~17 cm~-3 varies from 200 cm~2/V s to 1700 cm~2/V s at room temperature (RT) for x=40-100/100, respectivley.