Accession Number : ADA188306

Title :   Metal Contacts to Cadmium Telluride (CdTe).

Descriptive Note : Final rept.,

Corporate Author : UNIVERSITY COLL CARDIFF (WALES)

Personal Author(s) : Williams, R H ; Dharmadasa, I M

PDF Url : ADA188306

Report Date : Oct 1987

Pagination or Media Count : 93

Abstract : Metal-Cdte contacts, fabricated in three different CdTe surfaces were studied for a large number of metals. These surfaces were prepared by cleaving in ultra high vacuum, cleaving in air and etching in 1% bromine in methanol solution. The nature of these CdTe surfaces was investigated using ESCA, AES and SXPS techniques. The studies concentrated mainly on the more surface sensitive technique; SXPS, using synchroton radiation of photon energy 100 eV. It has been found that the air-cleaved and chemically etched CdTe, consists of TeO2 on the surface. The most commonly used chemical etchant for CdTe, 1% bromine in methanol, preferentially removes Cd from the CdTe surface. Microscopic interactions between evaporated metal and CdTe were monitored during the initial stages of interface formation using the SXPS technique. Au, Ag, Cr and Mn were selected for these studies; Au and Ag to represent the noble metals and Cr and Mn to represent more reactive metals. These studies reveal that almost all metals react with CdTe and with its native oxide, TeO2 at room temperature. Ag shows an inert behaviour on TeO2. Although the reactions between noble metals are unexpected, a strong out-diffusion of Te is observed in these cases. Keywords: Semiconductor interfaces, Cadmium tellurides.

Descriptors :   *CADMIUM TELLURIDES, *INTERFACES, *METAL CONTACTS, *METALS, *SEMICONDUCTORS, CARBINOLS, ETCHING, INTERACTIONS, METHODOLOGY, MICROSCOPY, OXIDES, PRECIOUS METALS, REACTIVITIES, SENSITIVITY, SOLUTIONS(GENERAL), SURFACES, ULTRAHIGH VACUUM

Subject Categories : Electrical and Electronic Equipment
      Inorganic Chemistry
      Fabrication Metallurgy

Distribution Statement : APPROVED FOR PUBLIC RELEASE