Radiation Tolerant High Voltage Silicon Carbide Switches

As set forth in a recent NASA Technology Roadmap, the current state of the art for a space radiation hardened power distribution component is limited to lt;nbsp;200 V. To achieve the technology performance goal of gt;nbsp;300nbsp;V for the derated semiconductor operating voltage, new technologies are needed. An example immediate benefit of space hardened high voltage parts is that they would enable next generation high-power electric propulsion systems. Use of a wide bandgap semiconductor such as silicon carbide is also likely to increase their efficiency.nbsp;The mature silicon technology has not been able to offer discrete very high power and radiation resistant components with favorable electrical characteristics such as low losses and high frequency operation capabilities. Silicon carbide power devices offer a unique opportunity with possible derated voltages of several hundreds of volts or larger. However, the nascent silicon carbide technology, which is in its infancy compared to silicon but significantly more mature relative to other wide bandgap technologies such as gallium nitride and gallium oxide, requires radiation hardening by design and process to achieve this.nbsp;We propose novel silicon carbide LDMOS and DMOS power device designs that are radiation tolerant. These designs are guided by results of detailed simulations, and extensive empirical data from previous radiation tests. Moreover, the proposed radiation tolerant power switch is likely to increase modularity of high and low power switchgear, and therefore reduce the logistics of incorporating interchangeable parts. This proposal directly addresses the capability performance goals of a)nbsp;developing basic power building blocks for multiple applications, and b)nbsp;distributing power at increased voltage to lower overall power system mass. Our silicon carbide electronics is additionally capable of addressing technology performance goal of power distribution components and interconnects at high temperatures.