High Quantum Efficiency, Low-noise, Radiation-tolerant AlGaP CCD-UV

ASTROPOWER PROPOSES TO DEVELOP A NEW FRONT-ILLUMINATED, ALUMINUM GALLIUM PHOSPHIDE (AlGaP) BASED, CHARGE-COUPLED DEVICE (CCD), ULTRAVIOLET (UV) IMAGING ARRAY. THIS NOVEL ARRAY TECHNOLOGY HAS NEVER BEEN SUCCESSFULLY DEVELOPED. THREE NEW INNOVATIONS WILL BE NECESSARY TO ACOMPLISH THE AlGaP CCD. THESE ARE: AlGaP MATERIAL QUALITY WHICH CAN SUPPORT A CCD DEVICE; THE GROWTH OF A NATIVE OXIDE ON THE AlGaP; AND THE USE OF A TRANSPARENT GATE ELECTRODE. IT WILL COMBINE THE KEY FEATURES OF THE HIGH BANDGAP AND EXCEPTIONAL QUALITY OF EPITAXIAL AlGaP WITH THE PREVIOUSLY MENTIONED INNOVATIONS. THE CONCEPTUAL DESIGN IS SHOWN IN FIGURE 1. A UNIQUE PLANAR FABRICATION PROCESS BASED ON DEVICE-QUALITY NATIVE OXIDES GROWN ON HIGH Al-COMPPOSITION AlGaP LAYERS WILL BE DEVELOPED. ASTROPOWER'S PRIOR EXPERIENCE WITH LIQUID PHASE EPITAXIAL GROWTH AND FABRICATION OF HIGH QUALITY GALLIUM PHOSPHIDE DEVICES WILL BE USED TO APPLY THE AlGaP INNOVATIONS FOR THE DEVELOPMENT OF SUPERIOR UV-CCD DEVICES. THE PROPOSED ARRAY WILL MEET THE REQUIREMENTS OF SPACE MISSIONS FOR NON-SILICON, HIGH-QUANTUM EFFICIENCY, LOW-NOISE, RADIATION-TOLERANT IMAGING ARRAYS FOR THE ULTRAVIOLET REGIONS OF THE SPECTRUM.