Liqiuid Crystal Display Fabricated from Laser Recrystallized Silicon on Bulk Fused Silica

Abstract

ABSTRACTThis paper discusses four aspects of fabrication of an active address liquid crystal array from laser recrystallized polycrystalline silicon: recrystallization, processing, device performance and array fabrication. The recrystallization process produces material which is imperfect by silicon wafer standards, but which contains few incoherent defects. The material was used to fabricate discrete n-channel MOS devices which had consistent off currents of 10−11 amps (0.4pA/μm of channel width) and on currents of 10−4 amps. Device threshold is controlled to + 200 mV and channel mobility is 500 to 600 cm2 /V-sec. The crossovers between Al/1% Si source and degenerately doped polycrystalline silicon gate lines were fabricated by use of high temperature reflowed, phosphorus doped chemical vapor deposited SiO2. Completed arrays had very few defects (no crossover defects and 0.3% bad devices).