Low-temperature growth of in situ phosphorus-doped silicon films: two-stepgrowth utilizing amorphous silicon buffers

Two-step growth has been developed to achieve in situ phosphorous-doped epi taxial and polycrystalline Si films, and the characteristic transitions in microstructures have been investigated for different phosphorus concentrati ons and annealing conditions of Si buffers. Our experimental results showed microstructures of Si films were controlled significantly by phosphorus do ping and annealing of Si buffers grown at low temperature. While undoped Si buffers grown at 500 degrees C were deposited as amorphous, Si buffers wit h phosphorus doping above similar to 10(20) cm(-3) converts the growth mode s from amorphous to single crystalline. Moreover, we thought that heavily d oped phosphorus could dissociate native oxide at Si buffers/substrate inter face by kinetically activated process during annealing. Using heavily phosp horus doped buffers, we can get high quality epi Si films. In addition, uni form polycrystalline Si films grew on undoped Si buffers. (C) 2000 Elsevier Science S.A. All rights reserved.