Stress-enhanced mobility in MOSFETs fabricated in zone-melting-recrystallized poly-Si films

N-channel enhancement-mode MOSFETs have been fabricated in Si films prepared by zone-melting recrystallization of poly-Si deposited on SiO2- coated Si, fused quartz, and sapphire substrates. Because the films on fused quartz are under a large tensile stress, the devices in these films exhibit surface electron mobilities as high as 860 cm²/V-s, compared to 620 cm²/V-s reported for similar devices in bulk single-crystal Si.