MINORITY-CARRIER LIFETIME IMPROVEMENT BY GETTERING IN SI1-XGEX

Monocrystalline Si1-xGex alloys may be an interesting material for infrared solar applications and dual band gap systems such as GaAs/Si1-xGex. At present, monocrystalline ingots of Si1-xGex have been grown by the float zone (FZ) technique, but the minority carrier lifetime in the wafers is quite low. Gettering treatment by POCl8 over Si1-xGex samples brings about a substantial improvement of minority carrier lifetime, achieving values similar to FZ-silicon wafers, that is over 200 mu s in high resistivity samples if the Ge constant is below 5%. (C) 1995 American Institute of Physics.