Accession Number : ADA299283

Title :   A Molecular Beam Epitaxy Growth Technique for Quality 1.5 - 2.5 Micrometers near Infrared Sensing Devices.

Descriptive Note : Final rept. 30 Sep 94-30 Mar 95,

Corporate Author : SENSORS UNLIMITED INC PRINCETON NJ

Personal Author(s) : Cohen, Marshall J.

PDF Url : ADA299283

Report Date : 30 MAR 1995

Pagination or Media Count : 37

Abstract : The objective of this Program is to develop long wavelength, lattice mismatched InGaAs PIN diode structures grown using Molecular Beam Epitaxy (MBE). The overall goal is to generate structures sensitive to the entire near infrared (1.0 - 2.5 micrometers) which take advantage of the uniformity inherent to MBE but with a buffer structure practical for commercialization. The activity during Phase I was centered on an intermediate alloy, In(.74)Ga(.28)As, with optical response out to 2.2 micrometers. By the end of Phase I, PIN diodes were fabricated using thin (less than 3 micrometers), low-temperature linearly graded buffers (LTLGB) of In(x)Ga(1-x)As. The diodes had grown-in p-n junctions and InAlAs passivation caps. Shunt resistivities (RoA) > 75 ohms sq cm, and peak quantum efficiencies > 70% were observed at room temperature. RoA had a temperature dependence with a diode quality factor of n=1 .2. These results were near-commercial in level and represent the first practical alternative to non-uniform vapor phase epitaxy (VPE) material. During Phase II, the conventional planar process (zinc-diffused junctions through an InAsP cap) will be adapted to accommodate the MBE InAlAs cap, the opaque InGaAs LTLGB will be replaced by a transparent InAlAs buffer to enable backside-illuminated devices, and the indium content of the active layer will be increased to 82% for a cutoff wavelength of 2.5 micrometers jg p.3.

Descriptors :   *EPITAXIAL GROWTH, *MOLECULAR BEAMS, *NEAR INFRARED RADIATION, THERMAL PROPERTIES, DIODES, BUFFERS, OPTICS, DETECTORS, LAYERS, GALLIUM ARSENIDES, STRUCTURES, ALLOYS, VAPOR PHASES, ROOM TEMPERATURE, QUALITY, ALUMINUM, PLANAR STRUCTURES, ELECTRICAL RESISTANCE, LONG WAVELENGTHS, PIN DIODES, INDIUM, NONUNIFORM, SHUNTS.

Subject Categories : Inorganic Chemistry
      Crystallography
      Atomic and Molecular Physics and Spectroscopy
      Optics

Distribution Statement : APPROVED FOR PUBLIC RELEASE