We report in-situ boron doping of Si1-xGex films epitaxially grown on Si(100) by low-pressure chemical vapor deposition (LPCVD) processes. The experiments are performed in an ultraclean hot-wall system using ultra-pure SiH4-GeH4-H2 -B2H6 gas mixtures. The incorporation rate of B was proportional to the B2H6 partial pressure and was larger for Ge-rich films. It was proposed that the increase in B incorporation rate with increasing Ge fraction was caused by the larger surface adsorption rate of B-hydride on Ge atoms than on Si atoms. Since the incorporation rate of B increased with exposure time of B2H6 during Si1-xGex deposition at early stage, it was suggested that B doping was limited by the B-hydride adsorption rate. Hall measurements showed that carrier concentration was equal to B concentration in the range 3×1017-2×1020cm-3 regardless of the Ge fraction, and Hall mobility passed through a minimum value for Si0.75Ge0.25 films regardless of the films thickness.
|Number of pages||6|
|Journal||Journal De Physique. IV : JP|
|Publication status||Published - 1993 Jan 1|
|Event||Proceedings of the 9th European Conference on Chemical Vapour Deposition - Tampere, Finl|
Duration: 1993 Aug 22 → 1993 Aug 27
ASJC Scopus subject areas
- Physics and Astronomy(all)