Inductively coupled plasma etch damage in 4H-SiC investigated by Schottky diode characterization

Abstract

Ti Schottky diodes have been used to investigate the damage caused by inductively coupled plasma (ICP) etching of silicon carbide. The Schottky diodes were characterized using TV and CV measurements. An oxidation approach was tested in order to anneal the damage, and the diode characterization was used to determine the success of the annealing. The barrier height, leakage current, and ideality factor changed significantly on the sample exposed to the etch. When the etched samples were oxidized the electrical properties were recovered and were similar to the unetched reference sample (with oxidation temperatures ranging from 900 degreesC up to 1250 degreesC). Annealing in nitrogen at 1050 degreesC did not improve the electrical characteristics. A low energy etch showed little influence on the electrical characteristics, but since the etch rate was very low the etched depth may not be sufficient in order to reach a steady state condition for the surface damage.