Study of Single- and Dual-Channel Designs for High-Performance Strained-Si–SiGe n-MOSFETs

Results comparing strained-Si-SiGe n-channel MOSFET performance of single-and dual-surface channel devices fabricated using 15% Ge content SiGe virtual substrates are presented. Device fabrication used high thermal budget processes and virtual substrates were not polished. Mobility enhancement factors exceeding 1.6 are demonstrated for both single-and dual-channel device architectures compared with bulk-Si control devices. Single-channel devices exhibit improved gate oxide quality, and larger mobility enhancements, at higher vertical effective fields compared with the dual-channel strain-compensated devices. The compromised performance enhancements of the dual-channel devices are attributed to greater interface roughness and increased Ge diffusion resulting from the Si/sub 0.7/Ge/sub 0.3/ buried channel layer.