Accession Number : ADA297557

Title :   Improved Gallium Nitride and Aluminum Nitride Electronic Materials.

Descriptive Note : Annual rept. 20 Feb 91-19 Jun 94,

Corporate Author : WESTINGHOUSE SCIENCE AND TECHNOLOGY CENTER PITTSBURGH PA

Personal Author(s) : Partlow, W. D. ; Choyke, W. J. ; Devaty, R. P. ; Yates, John T., Jr. ; Bornscheuer, K. H.

PDF Url : ADA297557

Report Date : 1994

Pagination or Media Count : 98

Abstract : This report describes the results of a three year program to improve the quality of Group III nitride electronic materials. The effort was directed toward understanding and controlling surface-reactive chemical paths toward the growth of GaN. We demonstrated low temperature synthesis of GaN from trimethyl gallium and ammonia by two techniques: a two-step process using atomic hydrogen and electron beams, and a single step process using only an electron beam. The electron beam activation made it possible to grow GaN in patterns. Several novel tools for the growth and processing of semiconductor materials resulted from this work. (1) A liquid N2-cooled reflector source of atomic hydrogen was developed for chemical activation and reactive cleaning of semiconductor surfaces. (2) An electron beam was used to stimulate the GaN synthesis reaction, providing a tool for activation of growth reactions which is an alternative to ion beams. These techniques were particularly effective in removing carbon associated with the methyl radical. In a parallel effort we carried out cathodoluminescence and infrared reflectance studies of GaN, AlN, superlattices, heterostructures with related wideband materials, providing information on the material defects and structure. We developed a model which allows the extraction of structural information of the component materials from infrared reflectance measurements near the restrahlen region. jg

Descriptors :   *ALUMINUM COMPOUNDS, *ELECTRONIC EQUIPMENT, *NITRIDES, *GALLIUM COMPOUNDS, INFRARED DETECTION, MEASUREMENT, LOW TEMPERATURE, ACTIVATION, REMOVAL, METHYL RADICALS, SYNTHESIS, CHEMICALS, STRUCTURAL PROPERTIES, MATERIALS, PROCESSING, COMPOSITE MATERIALS, SUPERLATTICES, REACTIVITIES, ION BEAMS, SEMICONDUCTORS, CARBON, AMMONIA, HYDROGEN, SURFACES, ELECTRON BEAMS, DEFECTS(MATERIALS), BROADBAND, GROUP III COMPOUNDS, CATHODOLUMINESCENCE, REFLECTANCE, INFRARED RADIATION, ATOMIC STRUCTURE, ATOMIC BEAMS.

Subject Categories : Inorganic Chemistry
      Physical Chemistry
      Electrical and Electronic Equipment
      Crystallography
      Optics

Distribution Statement : APPROVED FOR PUBLIC RELEASE