SBIR Phase I: High Gain, Low Noise Integrated SiC Optoelectronic Isolation for High Temperature Electronics

This Small Business Innovation Research Phase I project will investigate the feasibility of utilizing Silicon Carbide (SiC) based electronics to create wide-temperature, low-noise, high-speed optoelectronic sensors for high-voltage power electronics isolation applications. SiC electronics are a unique technology that has begun to take hold for high efficiency, high power density electronics capable of operating beyond 300 deg C. SiC has shown potential to provide solutions for light generation and detection with the advent of SiC Light Emitting Diodes (LEDs) and photodiodes. Existing photo-isolation components are hampered by their need for supporting silicon-based (low temperature) circuits required to amplify the small currents photodiodes generate. To achieve true wide-temperature, high-gain, high-speed and low-noise operation, proposed is the creation of an integrated SiC-based photo detector and pre-amplifier. Recent developments in low-voltage SiC transistors in commercial processes provide the path for this innovation, where the proposed photo detector may be directly incorporated into a SiC-based preamplifier circuit on a single chip to produce high-gain, low-noise photo detector capable of operating over a wide range of temperature. The wide band-gap of SiC makes the proposed detector suitable for a variety of light processing, control and transformation applications in the ultraviolet, visible and infrared range. The broader impact/commercial potential of this project will be evident in industrial, automotive, aerospace, oil exploration, water purification and high-voltage safety/control applications. The innovative application of advanced SiC device structures proposed will create a SiC-based photo detector capable of high-gain, low-noise, high-speed operation reliably over a very wide temperature range (in excess of 225 deg C). The proposed device would have immediate impact to applications requiring opto-electric isolation such as in high-voltage/high-power power conversion systems. The practical temperature range of state-of-the art optical isolators is limited by their silicon components to 125 deg C, which complicates thermal management and limits application in extreme environments. As such, state-of-the art high-temperature electronics applications typically utilize slow and cumbersome magnetic approaches. Further, the developed technology can be easily applied to UV source calibration commonly needed in water and food purification and flame/arc detection circuits. This market presents a unique challenge for current technologies such as Silicon or GaP, as UV rays are a well-understood reliability problem in Si and GaP photo-detectors. An opportunity thus exists to apply SiC to photo-detection/isolation applications to fill a gap in existing technologies and provide new solutions in support of the engineering design of systems used in these critical applications.