Silicon Carbide Using a Pulsed Seeded Supersonic Molecular Beam

Silicon and gallium arsenide cannot meet some of the power, frequency, temperature and speed requirements of the next generation of electronic devices. Therefore, alternative semiconductor materials for electronic devices must be developed. Silicon carbide has many required properties such as wide bandgap, high breakdown field, high electron saturation velocity, and physical strength making it attractive for many applications. Commercial silicon carbide substrates, however, suffer from defects such as micropipes and high etch pit densities. Homoepitaxial SiC growth on these substrates results in antiphase domain boundary defects which cause mixed phase polytypes to form, limiting the crystal quality. These shortcomings may be eliminated by using supersonic beam deposition in the homoepitaxial growth process. Systems & Processes Engineering Corporation proposes to develop a silicon carbide growth process based on pulsed seeded supersonic beam deposition. The seeded molecular beam enables variation of the incident energy of the arriving particles to optimize the growth conditions. Pulsing the beam lowers the background gas and enables the surface to relax after each monolayer of deposition ensuring high growth quality. By varying the deposition temperature, carbon containing source gases and beam energy we will explore growth of high quality silicon carbide of a specified polytype.