Large grained polycrystalline silicon films by solid phase crystallization of phosphorus-doped amorphous silicon

Abstract

For the first time, polycrystalline Si films with a grain diameter exceeding 10 μm are prepared by solid phase crystallization of phosphorus-doped, amorphous Si films on glass. Low pressure chemical vapour deposition from Si2H6PH3 serves to form amorphous Si films on glass substrates which are then subsequently solid phase crystallized at a temperature of 600°C. Transmission electron microscopy shows a log-normal grain size distribution in the crystallized films. The average grain size increases with the phosphorus concentration in the films and reaches 3.1 μm at an electron concentration of 1.5 × 1020cm−3. The area weighted average grain size is 5.9 μm. Hall effect measurements yield an electron mobility of about 50 cm2/(V s) for electron concentrations above 1019 cm–3.