Chemical etching of isolation grooves in high-power silicon devices

Abstract

The procedure of wet chemical etching, which plays an important role in the fabrication of high-power Si devices in standard commercial equipment, is discussed. The characteristics of isolation grooves in Si high-voltage thyristors and diodes have been investigated, with respect to etchants and wet etching conditions. It has been found that the standard deviation in the depth values of isolation grooves produced in the Si wafer of 125 mm in diameter is reduced to 0.85 µm using a proposed modified technological procedure.