Effects of Substrate Orientation and Channel Stress on Short-Channel Thin SOI MOSFETs

Abstract—We present a study of the effects of substrate ori-entation and longitudinal channel stress on the performance of extremely thin silicon-on-insulator (ETSOI) MOSFETs with gate lengths down to 25 nm. We find that short-channel electron and hole mobilities follow the long-channel mobility trends versus substrate orientation and longitudinal channel stress. We show that with respect to (100) silicon-on-insulator (SOI) substrates, short-channel ETSOI MOSFETs on (110) SOI substrates lead to 25 % enhancement of the p-channel FET drive current at the expense of 12 % degradation of the n-channel FET drive current at a fixed OFF-current of 100 nA/μm and a supply voltage of 1 V. Finally, we estimate that an ETSOI complemen-tary metal–oxide–semiconductor (CMOS) on (110) SOI substrates should lead to 10 % faster ring oscillators compared with those on (100) SOI wafers, which also implies that (100)-oriented wafers with (110) sidewalls are a better choice for fabricating nonplanar FinFETs and trigate CMOS circuits. Index Terms—Complementary metal–oxide–semiconductor field-effect transistors (CMOSFETs), fully depleted silicon-on-insulator (FDSOI), mobility, substrate. I