Low Pressure Chemical Vapor Deposition of In Situ Boron-Doped Polysilicon
The deposition of in situ boron-doped polysilicon from a mixture of diborane and silane was studied over a temperature range of 450°-600°C, and a diborane/silane flow ratio varying from 0.002 to 0.02. Diborane enhances the deposition rate and suppresses the activation energy of the deposition reaction. Diborane also reduces the temperature of the amorphous/ polycrystalline transition. Resistivity after annealing (650° or 900°C) decreases with increasing diborane flow and with decreasing deposition temperature. Minimum resistivity is obtained by depositing the silicon as an amorphous film and annealing at high temperature (≥900°C). Of particular importance to low thermal budget processes, however, is the low resistivity (3.0 mΩ-cm) obtained by annealing an initially amorphous film at 650°C.
|Journal||Journal of the Electrochemical Society|
Maritan, C.M., Berndt, L.P., & Tarr, N.G. (1988). Low Pressure Chemical Vapor Deposition of In Situ Boron-Doped Polysilicon. Journal of the Electrochemical Society, 135(7), 1793–1796. doi:10.1149/1.2096132