Low‐Temperature Si Epitaxial Growth by Electron Cyclotron Resonance Plasma Chemical Vapor Deposition

Silicon epitaxial growth was studied using the microwave electron cyclotron resonance (ECR) plasma‐enhanced chemical vapor deposition (CVD) method with SiH 2 Cl 2 / HCl gases. The Si films grown at 650°C low temperature were confirmed, from reflection high energy diffraction and secondary ion mass spectroscopy analyses, to have epitaxial characteristics and abrupt impurity transition regions. However, 10 19 cm −3 chlorine impurities, due to decomposition of the source gas, were incorporated into the epi layer. When injecting HCl into the SiH 2 Cl 2 gas, an incubation period for Si nucleation on the SiO 2 regions appeared. The Si deposition delay time on the SiO 2 regions, which resulted in the incubation period, increased with raising the substrate temperature. Selective epitaxy could be achieved during the Si deposition delay time when epitaxial Si was deposited on the Si substrate but not on the SiO 2 regions. Also, heavy boron doping was carried out using the low‐temperature ECR plasma CVD technique with BCl 3 introduction. The doping concentration was 1 × 10 20 cm − 3 with abrupt impurity transition. Though boron in as‐deposited epi layer, grown at 650°C substrate temperature, was not activated, the activation ratios reached almost 100% by a rapid thermal annealing (RTA) treatment at 1000°C for 10 s.