This paper describes an experimental investigation on the infrared radiative properties of heavily-doped silicon (Si) at room temperature. Lightly-doped Si wafers were ion implanted with boron and phosphorus atoms to doping concentrations of 1×1020 and 1×1021 cm−3. Rapid thermal annealing was performed to activate the implanted dopants. A Fourier-transform infrared spectrometer was employed to measure the normal transmittance as well as reflectance of the samples in the spectral region from 2 to 20 μm. Accurate carrier mobility and ionization models were identified after carefully reviewing the available literature, and then incorporated into Drude model to predict the dielectric function of doped Si. The radiative properties of doped Si samples were calculated by treating the doped region as multilayer thin films of different doping concentrations on a thick Si substrate. The measured spectral transmittance and reflectance agree well with the model predictions. The results obtained from this study will facilitate the future applications of heavily-doped Si in semiconductor as well as MEMS devices.
Technique for measurement of the minority carrier mobility with a bipolar junction transistor
