SCHOTTKY BARRIER PHOTOVOLTAIC DETECTOR AND PROCESS

• Main Authors: HARNAGEL, GARY L, HARRISON, JOSEPH M, TWADDELL, VICTOR A, LAGA, GERRY T
• Format: Patent
• Language: English; French
• Published: 20.12.1983
• Edition: 3
• Subjects: BASIC ELECTRIC ELEMENTS; COLORIMETRY; ELECTRIC SOLID STATE DEVICES NOT OTHERWISE PROVIDED FOR; ELECTRICITY; MEASUREMENT OF INTENSITY, VELOCITY, SPECTRAL CONTENT,POLARISATION, PHASE OR PULSE CHARACTERISTICS OF INFRA-RED,VISIBLE OR ULTRA-VIOLET LIGHT; MEASURING; PHYSICS; RADIATION PYROMETRY; SEMICONDUCTOR DEVICES; TESTING

A platinum-cadmium sulfide Schottky barrier photovoltaic detector which is capable of sensing near ultraviolet and short wavelength visible radiation with extremely small response to wavelengths longer than about 5200 angstroms. The detector is fabricated with both the ohmic and barrier contacts located on the same side of the cadmium sulfide substrate to facilitate wire attachment by high-speed bonding techniques. A titanium-gold-titanium infrared shield structure is deposited directly on the substrate and is utilized to provide a connection between the ohmic contact and the substrate. An insulating layer of silicon dioxide covers the shield structure. A thin layer of platinum is deposited directly on the substrate in a small central optically active area surrounded by the insulated shield structure. A metal boundary layer overlies the periphery of the platinum layer and prevents the barrier contact metalization from affecting the properties of the Schottky barrier. Both the ohmic and barrier contacts may be formed of a titanium adhesion layer and a layer of gold. The gold portions of these contacts touch the shield structure and the boundary layer through separate windows etched in the silicon dioxide insulating layer.