High conductivity polycrystalline silicon obtained by molecular beam deposition

The structural and electrical properties have been investigated of antimony doped polycrystalline silicon films obtained by molecular beam deposition on oxidized silicon substrates. We show that low-resistivity films with smooth morphology are obtained by solid phase crystallization of antimony doped amorphous silicon layers deposited at 250 °C. A resistivity of 4.3 mΩ cm is obtained by crystallizing the films at temperatures as low as 650 °C for 15 min. In situ crystallization of the amorphous silicon is absolutely necessary to achieve low resistivities. We also show that direct deposition above 650 °C gives rise to polycrystalline silicon with much higher resistivities.