This Small Business Innovation Research (SBIR) Phase I project addresses a novel processing technique to deposit silicon carbide (SiC) boules for wafer production. Currently SiC boules are produced using sublimation techniques from solid SiC source materials. Sublimation boule growth requires high temperatures (> 2000 C) and is plagued by high defect and contamination levels. The proposed deposition technique will use high-purity gas precursors and has the potential to produce large diameter SiC boules with low contamination levels and reduced defect levels at a reduced cost. The gas-phase temperature and substrate temperature are decoupled, allowing for the growth of single crystal SiC with reduced stress. Additionally the deposition system is scalable with the capability of producing large-diameter wafers. This project will explore the feasibility of single crystal SiC boule growth using SiH4 and C2H6 precursors. In this work the optimal process window for high-rate single crystal SiC deposition will be identified, and the chamber design will be optimized for extended run-times required for boule production.
SiC is a wide band gap compound semiconductor with high thermal conductivity, high breakdown electric field strength, thermal stability and chemical inertness. SiC-based electronics are of great interest because they can significantly outperform conventional semiconductors under high-temperature, high-power, high-radiation, and corrosive conditions. Potential products based on SiC include engine control electronics, turbine engine sensors, power switching devices, microwave electronics, and many others. Several companies are currently producing SiC wafers, but prices remain extraordinarily high. This technique could produce a strong competitive advantage over current sublimation techniques. By overcoming the existing defect, wafer diameter, and price limitations, this novel process of SiC growth could significantly increase research and commercial production of SiC based devices.
