SYNCHROTRON-RADIATION-INDUCED PHOTODOPING USING DISILANE MOLECULAR-BEAM EPITAXY - LOW-TEMPERATURE HIGH DOPING OF B

Synchrotron-radiation (SR)-induced doping of B has been demonstrated u sing disilane molecular-beam epitaxy. By SR irradiation, B incorporati on is enhanced by two to five times compared to growth without SR irra diation at 550 degrees C. Doped epitaxial film can be obtained using S R even at 80 degrees C where conventional gas-source molecular-beam ep itaxy cannot, so far, achieve Si epitaxy. It was found that B concentr ation has linear dependence on the decaborane partial pressure. This s uggests that the B incorporation is limited by the photolysis of decab orane and the photoinduced removal of hydrogen from adsorbed B hydride s. it was also observed that the electrical activation rate of B is en hanced by SR irradiation especially in the region where B concentratio n is close to the solid solubility. (C) 1996 American Institute of Phy sics.