Silicon-on-Insulation MOSFETs Fabricated in Zone-Melting-Recrystallized Poly-Si Films on SiO2.

摘要

N- and p-channel enhancement-mode MOSFETs have been fabricated in Si films prepared by zone-melting recrystallization of poly-Si deposited on SiO2-coated Si substrates. The transistors exhibit high surface mobilities, in the range of 560-620 cm sq cm/V-s for electrons and 200-240 sq cm/V-s for holes, and low leakage currents of the order of 0.1 pA/micrometer (channel width). Uniform device performance with a yield exceeding 90% has been measured in tests of more than 100 devices. The interface between the Si film and the SiO2 layer on the substrate is characterized by an oxide charge density of 1-2 x 10 to the 11th power/sq cm and a high surface carrier mobility. N-channel MOSFETs fabricated in Si films recrystallized on SiO2-coated fused quartz subtrates exhibit surface electron mobilities substantially higher than those of single-crystal Si devices because the films are under a large tensile stress.