Thinning of a Two-Inch Silicon Carbide Wafer by Plasma Chemical Vaporization Machining Using a Slit Electrode

Abstract

In recent years, silicon (Si) has been mainly used in power devices, but the limit of its performance is being reached. Therefore, silicon carbide (SiC) power devices have been attracting attention because they enable the fabrication of devices with low power consumption. To reduce the on-resistance in vertical power transistors, backside thinning is required after device processing. However, it is difficult to thin a SiC wafer with a high removal rate by conventional mechanical processing because its high hardness and brittleness cause cracking and chipping during thinning. Therefore, we have attempted to thin a SiC wafer using plasma chemical vaporization machining (PCVM), which is plasma etching using atmospheric-pressure plasma. In this study, we describe a machining property using a newly developed slit electrode that is composed of two parts and has a slit that allows for a new gas to pass.