Zone-melting recrystallization of encapsulated silicon films on SiO2—morphology and crystallography

Abstract

Large‐area films of recrystallized Si with (100) texture, preferred in‐plane orientation, and grain sizes ≳1× 10 mm have been produced by using a strip‐heater oven to move a narrow molten zone across Si films on SiO₂. A composite encapsulation layer of SiO₂ and Si₃N₄ over the Si leads to smooth surfaces and (100) texture. The 〈100〉 axes of grains tend to lie along the direction of motion of the molten zone. A grid of faceted pits etched anisotropically into the Si permits determination of local orientation. As described elsewhere, the recrystallized films have been used for the fabrication of metal‐oxide semiconductor field‐effect transistors which exhibit electron surface mobilities comparable to devices fabricated on single‐crystal Si.