High-Voltage n-Channel IGBTs on Free-Standing 4H-SiC Epilayers

In this paper, we describe a process for fabricating high-voltage n-channel double-diffused metal-oxide-semiconductor insulated gate bipolar transistors (IGBTs) on free-standing 4H silicon carbide (SiC) epilayers. In this process, all critical layers are epitaxially grown in a continuous sequence. The substrate is then removed, and device fabrication takes place on the carbon face of a free-standing epilayer having a total thickness of about 180 mu m. For a drift layer with doping and thickness values capable of blocking 20 kV, the n-channel IGBT carries 27.3-A/cm(2) current at a power dissipation of 300 W/cm(2), with a differential ON-resistance of 177 m Omega . cm(2). To our knowledge, this is the first detailed report of device fabrication on free-standing SiC epilayers.