PHOTOLUMINESCENCE STUDY OF PHOSPHORUS-DOPED LPCVD SILICON EPILAYERS DEPOSITED FROM DICHLOROSILANE

A set of phosphorus-doped low pressure chemical vapor deposition Si epilayers grown from PH3/SiH2Cl2 have been characterized using both dispersive and FTIR photoluminescence (PL) spectroscopy. By simultaneously growing each layer on three types of substrate, subsequent PL analysis can unambiguously identify epilayer emission. The principal shallow dopant has a relatively high radiative efficiency in all layers deposited within the temperature range 850-1050-degrees-C, there being no evidence for any competing deep radiative centers within the 0.7-1.1 eV photon range. It is shown, for the first time, that shallow bound exciton luminescence from thin (approximately 1-mu-m) Si epilayers grown at low temperature can be readily observable. Photoluminescence is also shown to be capable of qualitatively monitoring variations in vertical and lateral autodoping of epilayers from heavily doped substrates.