ELECTRONIC-PROPERTIES OF DEFECTS INTRODUCED IN P-TYPE SI1-XGEX DURINGION ETCHING

We have investigated the electronic properties of defects introduced i n boron-doped, strained p-type Si1 - xGex (x=0-0.15) during 0.75-keV a rgon Ar-ion etching, by deep level transient spectroscopy. These defec ts are compared to those introduced during e-beam deposition of metal contacts and after 5.4-MeV alpha-particle irradiation. Defect HArld, d etected in p-Si, has similar electronic properties as He2 and Hal5 det ected after electron and alpha-particle irradiation, respectively. The variation in activation energy of HArld with Cc fraction was studied, and it was found to follow the same change as the band gap of straine d Si1 - xGex. This defect has a concentration, which decreases sharply from the metal-semiconductor surface. It also has an activation energ y, which depends on the Ge content and is pinned to the conduction ban d. (C) 1998 American Institute of Physics. [S0003-6951(98)04328-9].