DEFECT CHARACTERIZATION OF SPUTTER-DEPOSITED AU CONTACTS ON N-TYPE SI1-XGEX

Sputter deposition of metal Schottky contacts on semiconductors create s damage at and below the surface, often resulting in inferior rectifi cation properties. We have used deep-level transient spectroscopy (DLT S) in an investigation of the electronic properties of defects introdu ced in n-Si1-xGex (x=0.0 to 0.25) during RF sputter deposition of 500 nm thick Au Schottky barrier diodes (SBDs). Seven discrete electron de fects (ES1-ES7) and a band of defects with a continuous distribution w ere detected after this processing stage. The defects are compared to those detected in the same material after high and low energy alpha-pa rticle irradiation. It was seen that ES5 detected after sputter deposi tion is actually two peaks superimposed on each other. Contributions f rom the E-centre and the divacancy make up this DLTS peak. ES5 has a s imilar DLTS signature to EA2 introduced during high energy (5.4 MeV) a lpha-particle irradiation.