Polarity-dependent effects in silicon carbide crystals: from fundamentals to applications

Abstract Whether in the form of zinc blende, wurtzite, or a composite structure of the two, silicon carbide (SiC) crystals possess a pair of polar crystal faces along the stacking direction of Si-C bilayers, namely the Si-face and the C-face. These two faces have different atomic structures and surface properties, resulting in anisotropic and surface polarity (SP)-dependent effects on growth and mechanical processing of SiC materials and electrical performance of SiC-based devices. Although much effort has been spent on the studies of the SiC polarity and SP-dependent effects, no systematic review of these studies has been reported. Herein, we aim to comprehensively outline the main aspects of the polarity-dependent effects of SiC, starting from the origin of polarity and culminating in a discussion on how SP affects device performance. Along the way, we will cover several methods for identifying SP and SP-dependent effects on crystal growth, mechanical processing and heteroepitaxy. The particular significance of this study lies in providing a clear research framework and overview that serves as a reference for future research and applications.