Propriedades eletrônicas de dispositivos MOS baseados em SiC

Abstract

Silicon Carbide (SiC) has been considered a promising material for high-power, highfrequency, high-temperature and harsh environments electronics, where existing technologies based on Si and GaAs fail to provide any satisfactory performance. This versatility is due to remarkable characteristics like its wide band gap, high electron mobility, high thermal conductivity, high breakdown eld, mechanical stability and endurance. In addition, SiC can be grown in more than 200 di erent polytypes, involving three di erent crystalline structures: cubic (zincblende), hexagonal (wurtzite) and rhombohedral. Another signi cant advantage over other wide bandgap semiconductors, is the ability to grow SiO2 layers on SiC by thermal oxidation, similarly to Si. Unfortunately, SiC-based devices cannot compete with Si-based technology in the areas of low cost, functional density and moderate temperature applications. Even though SiC technology has been advanced rapidly, there are still several problems to be issued like large-scale crystal growth, defects minimization and device performance, before it can reach full potential. This work aims the development theoretical and computational tools to investigate the electric and electronic properties of metal-oxide-semiconductor (MOS) capacitors based on SiC. The physical model adopted is based on the solution of the Poisson and Schrödinger coupled equations. The presented model is general enough to be used in more complex devices and tri-dimensional geometries. However, the basic physics that rules the operation of a full MOS Field E ect Transistor (MOSFET) can be perfectly captured by an one-dimensional modeling of MOS capacitors.