Accession Number : ADD014359

Title :   Sensitization Pretreatment of PB-Salt Epitaxial Films for Schottky Diodes by Sulfur Vapor Exposure.

Descriptive Note : Patent, Filed 27 Jul 88, patented 26 Sep 89,

Corporate Author : DEPARTMENT OF THE NAVY WASHINGTON DC

Personal Author(s) : Chu, Tak-Kin ; Santiago, Francisco

Report Date : 26 Sep 1989

Pagination or Media Count : 7

Abstract : This patent pertains to a process for preparing an infrared sensitive photodiode comprising the steps of: 1) forming by vacuum deposition an epitaxial layer of a semiconductor alloy material selected from the group consisting of PbSe, PbTe, PbSe(x)Te(1-x), Pb(y)Sn(1-y)Se, Pb(y)Sn(1-y)Te, Pb(y)Sn(1-y)Se(x)Te(1-x), Pb(z)Cd(1-z)Se, Pb(z)Cd(1-z)Te, and Pb(z)Cd(1-x)Se(x)Te(1-x), wherein 0x1, 0y1, and 0z-1, to cover at least a portion of the surface of a substrate composed of an infrared transparent single crystal material selected from the group consisting of alkali metal halides and, alkaline earth halides; 2) coating the epitaxial layer of semiconductor alloy material with a thin layer of a lead halide selected from the group consisting of PbCL2, PbBr2, PbF2, and mixtures thereof by exposing the epitaxial layer alloy material to vapor of the lead halide in the presence of a gas selected from the group consisting of air, oxygen, and oxygen/inert gas mixtures; 3) vacuum depositing Pb metal onto a portion of a lead halide coated epitaxial layer of semiconductor alloy material to form a non-Ohmic Pb metal contact; and 4) forming an Ohmic contact on another portion of the epitaxial layer of semiconductor alloy material; The improvement comprises after step (1) but before step (2), vacuum depositing a thin coating of sulfur onto the epitaxial layer of semiconductor alloy material by exposing the epitaxial layer to sulfur vapor. (aw)

Descriptors :   *EPITAXIAL GROWTH, *PATENTS, *PHOTODIODES, *SCHOTTKY BARRIER DEVICES, *VAPOR DEPOSITION, *LEAD COMPOUNDS, *SALTS, ALKALI METALS, ALKALINE EARTH COMPOUNDS, ALLOYS, COATINGS, SEMICONDUCTOR DIODES, ELECTRIC CONTACTS, EXPOSURE(GENERAL), HALIDES, INFRARED RADIATION, LAYERS, METAL COMPOUNDS, METAL CONTACTS, MIXTURES, OXYGEN, SEMICONDUCTORS, SENSITIVITY, SENSITIZING, SUBSTRATES, SULFUR, VACUUM DEPOSITION, THIN FILMS, INFRARED OPTICAL SYSTEMS, INFRARED OPTICAL MATERIALS, SINGLE CRYSTALS, TELLURIDES, SELENIDES, TIN COMPOUNDS, CADMIUM COMPOUNDS, CHLORIDES, BROMIDES, FLUORIDES, RARE GASES

Subject Categories : Electrical and Electronic Equipment
      Solid State Physics
      Electrooptical and Optoelectronic Devices

Distribution Statement : APPROVED FOR PUBLIC RELEASE