SBIR Phase I: Radiation Tolerant, High-Voltage, Silicon Carbide Devices

The broader/commercial impact of this Small Business Innovation Research (SBIR) Phase I project is to enable smaller, lighter, and higher-performance satellites, thereby making satellites cheaper to manufacture and launch. Lighter satellites reduce launch costs or permit greater payload performance for a given mass. Less fuel is required to launch lighter satellites, reducing the environmental impact of greenhouse gases generated during launch. Internet connectivity through satellite is becoming increasingly pervasive, and if costs continue to decline, it might become ubiquitous, supporting workforce development and educational outreach in hitherto unserved places. Many components, such as power supplies, can be made lighter and smaller when silicon carbide semiconductors are utilized in place of silicon high voltage devices in applications such as aerospace and satellites. The ultimate goal is to replace all silicon high-voltage devices in satellites and aerospace with silicon carbide products. It has been demonstrated that conventionally designed commercial high voltage silicon carbide materials cannot withstand the high radiation levels encountered in outer space applications. The objective of this project is to develop, manufacture, test, and demonstrate the viability of silicon carbide high voltage semiconductor products that are resistant to radiation levels comparable to those encountered in space. Commercially available silicon carbide (SiC) power devices are not approved for use in heavy ion radiation environments due to their susceptibility to catastrophic failure and burnout at voltages below 20% of the specified voltage when exposed to radiation. Consequently, SiC high voltage devices are not currently used in space applications, despite the fact that they offer very compelling features for mission-critical applications. Using simulation tools, the team has created a SiC junction barrier Schottky diode that can operate at up to 1200 V under high ion radiation. A radiation-resistant silicon carbide junction barrier Schottky diode rated at 1200 V will be designed, produced, and tested for radiation resistance. To accomplish the target radiation performance, a multi-pronged strategy will be applied, including novel device designs to reduce the electric field and mitigation of thermal runaway caused by ion strike when the device is under reverse bias. Schottky barrier materials with improved thermal stability will be used. Successful implementation of the intended approach will open the way for the integration of SiC Schottky diode devices in space applications. This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.