Main Differences in Processing Si and SiC Devices

Abstract

Due to the different physical properties of Si and SiC, many conventional Si device processing techniques cannot be directly transferred to SiC device fabrication. To deliver high-performance SiC commercial power devices, new techniques quite different from Si industry were developed in past decades for processing device, such as dopant implantation, metal contact, MOS interface, etc. On the other hand, the physics model behind many of these SiC processing technologies is not updated in the same pace that the success of them can still not be fully understood.The activation of dopants in 4H-SiC has been intensively studied, and the efforts are mainly put into two directions, namely, protecting the semiconductor surface morphology while at the same time maximising the active concentration of implanted dopants. Figure 1. Schematic graph showing a typical dopant thermal diffusion process using a gas source. Main Differences in Processing Si and SiC Devices

Solid state reactions between SiC and Ir

“…As practical example, in the unipolar devices such as metal-oxide-semiconductor field-effecttransistors (MOSFETs), the electrical resistance can be drastically reduced when Si is replaced by SiC. In addition, SiO2 acting as insulator in MOSFETs devices, can be easily layered on SiC substrate surface by thermal oxidation [4]. Moreover, the power and frequency ranges of SiC-MOSFETs are estimated around 1 kV break-down voltage and around 20 kHz switching frequency, then covering the wide requirements for all the common power electronic devices [5].…”