In situ B doping of SiGe(C) using BCl 3 in ultraclean hot-wall LPCVD

Abstract

In situ B doping of SiGe(C) epitaxial growth on Si using BCl 3 in ultraclean hot-wall LPCVD has been investigated at low temperatures around 500 °C. Alhough BCl 3 was used as doping gas, incorporation of Cl in the epitaxial film was under SIMS detection limit and no deterioration of the crystallinity was recognized by high-resolution XRD. The sheet resistance in-wafer uniformity in 200 mm diameter wafer of B-doped SiGe(C) using BCl 3 was around 2 σ%, which is much better than the case of B 2H 6 dopant gas (12 σ%). The deposition rate was scarcely changed with BCl 3 addition at the lower GeH 4 and BCl 3 partial pressures range corresponding SiGe(C)–HBT process condition. All the results assured that BCl 3 is promising as B doping gas for low temperature SiGe(C) epitaxial growth.