An Integrated SiC Photo-Transistor for Ultraviolet Detection in High-Temperature Environments

Jim Holmes, A. Matt Francis, Nicholas Chiolino, Matthew Barlow, Sonia Perez, Ian Getreu
Ozark Integrated Circuits, Inc.
Fayetteville, Arkansas, USA
Article published in IEEE Sensor Applications Symposium (SAS), March 2019.

Abstract— The work described herein applies a patented integrated silicon carbide (SiC) bipolar junction transistor (BJT) to the detection of ultraviolet (UV) light in situ for extreme-temperature environments. An integrated SiC BJT provides four important capabilities for UV detection in extreme environments: (1) The miniaturization of detectors and readout circuits through micron-scaled integrated circuit (IC) lithography; (2) the high-temperature operation of SiC ICs; (3) long-term reliability of SiC at high temperatures; and (4) the deep-UV responsivity of 4H-SiC. The design, manufacture and electrical characterization of a SiC photo-transistor is described. Photonic characterization of the photo-transistor responsivity in the vacuum ultraviolet (VUV) and near UV is analyzed. It will be shown that integration of the photo-transistor with SiC CMOS[1] advances the state-of-the-art to a photo-BiCMOS capability. The advancement of the state of the art is validated in both terrestrial and space-born applications, specifically (1) the patent-pending detection of the ultraviolet signature produced by the charge-compression auto-ignition of diesel fuel in a working 4-stroke engine, and (2) the measurement of Solar UV intensity in Low-Earth Orbit (LEO).

Keywords—SiC, BiCMOS, photo-transistor, ultraviolet, characterization, stratified charge-compression auto-ignition, low-Earth orbit

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