Status of SiC Power Devices and Manufacturing Issues

SiC materials and device technology has entered a new era with the commercialization and acceptance of 600 V/10 A and 1200 V/10 A Schottky Barrier Diodes (SBDs) in the marketplace. These diodes are finding applications in the Power Factor Correction (PFC) stage of Switch Mode Power Supplies (SMPS). SiC power MOSFETs with ratings of 8001200 V up to 10 A will soon be commercially available. The next step is to integrate the SiC MOSFET and Schottky diodes in a power module for PFC and motor control applications. The motor control application requires 1200 V/100 A devices. This represents a factor of 10 increase in the die area and hence the new manufacturing challenges have to be met in order to maintain high yields. These challenges include reduction of defects on the 3" wafers during epitaxy, flatter wafers and better control on the manufacturing processes such as guard ring dimensions. The other manufacturing issues are threshold voltage control in power MOSFETs, use of high temperature implants and bigger diameter substrates (4 inch in near future and 6 inch in a few years).