Electrical characterization of defects introduced during sputter deposition of tungsten on n type 4H-SiC

We have studied the defects introduced in n-type 4H-SiC during sputter deposition of tungsten using deep-level transient spectroscopy (DLTS). Current-voltage and capacitance-voltage measurements showed a deterioration of diode thermionic emission characteristics due to the sputter deposition. Two electrically active defects E0.29 and E0.69 were introduced. Depth profiling revealed that sputter deposition increases the concentration of the native Z1 defect. A comparison with prominent irradiation and process induced defects showed that the E0.29 was unique and introduced during sputter deposition only. The E0.69 may be silicon vacancy related defect.