Pressure dependence of i n s i t u boron-doped silicon films prepared by low-pressure chemical vapor deposition. II. Resistivity

The effects of silane pressure and temperature on the in situ boron incorporation and resistivity of low-pressure chemical vapor deposited polycrystalline silicon films were studied in the ranges of 2.5×10−3–1 Torr and 515–700 °C. By lowering the silane pressure, the boron concentration increases (up to 1×1022 cm−3) and the resistivity decreases down to about 2×10−3 Ω cm without annealing. For high deposition pressure (≥0.1 Torr), the resistivity decreases as the temperature is lowered. In this latter case the secondary-ion mass spectrometry profiles reveal a boron accumulation at the layer-substrate interface, which is always observed independently of the substrate nature.