Plasma sources for high-rate etching of SiC

摘要

SiC has become an attractive material for the semiconductor industry for both electronic devices and microelectromechanical systems (MEMS). Typical applications for SiC etching include through-wafer vias, shallow vias, and trenches for power devices; however, they suffer from inherently slow etch rates. In this work, SiC etch rates have been compared from two different inductively coupled SF_6 plasma sources for 250 μm-wide deep vias etched in 6H n-type SiC substrates, with a patterned nickel mask. SiC etch rates of 2.6-2.7 μm/min were obtained for one type of plasma source, making it possible to use plasma processing for MEMS applications and deep-etch electronic device processing such as wafer thinning, through-wafer via etching, and deep trench isolation.