Overview

In recent years SiC has metamorphisized from an R&D based materials system to emerge as a key substrate technology for a significant fraction of the world production of green, blue and ultraviolet LEDs. Emerging markets for SiC homoepitaxy include high-power switching devices and microwave devices. Applications for heteroepitaxial GaN-based structures on SiC substrates include laserss and microwave devices. In this paper we review the properties of SiC, assess the current status of substrate and epitaxial growth, and outline our expectations for SiC in the future.

Keywords: SiC substrates, blue LEDs, high power switching, physical vapor transport, vapor phase epitaxy, hot wall epitaxy.

1. Introduction

Following in the footsteps of Si and GaAs, wide bandgap semiconductors are currently transitioning from research and development into real world applications. The commercialization of SiC that started a decade ago with the release of SiC blue LEDs[l] has accelerated over the past few years. The improvements made in SiC semiconductor device technology for electronic and optoelectronic applications are due in part to the commercial availability of SiC substrates of ever-increasing diameter and quality. Examples of current state-of-the-art devices include: high brightness and ultra-bright blue and green InGaN-based LEDs which take full advantage of the electrical conductivity of the 6H-SiC substrate by employing a conductive AlGaN buffer layer; microwave MESFETs on semi-insulating 4H-SiC substrates with power densities as high...