Accession Number : ADA293936

Title :   Metalorganic Chemical Vapor Deposition of GaN, AlN and GaAlN for UV Photodetector Applications.

Descriptive Note : Annual technical rept. 1 Jul 94-31 Mar 95,

Corporate Author : NORTHWESTERN UNIV EVANSTON IL DEPT OF ELECTRICAL ENGINEERING

Personal Author(s) : Razeghi, Manijeh

PDF Url : ADA293936

Report Date : APR 1995

Pagination or Media Count : 59

Abstract : GaN, AlN and GaAlN epilayers were grown by low-pressure metalorganic chemical vapor deposition, on sapphire, silicon, and 6H-SiC. The X-ray diffraction linewidths were as low as 30 and 100 arcsecs for GaN and AlN respectively on sapphire. Sharp optical absorption edges were obtained for these films. Transmission electron microscopy characterized the films microstructurally. Photoluminescence (PL) at 300 and 77 K yielded linewidths of about 80 and 40 meV respectively for GaN on all substrates. However, no deep-level-associated yellow emission was detected from the GaN on SiC. Unintentionally n-type doped GaN had an electron mobility as high as 200 sq cm/Vs at 300 K. As-grown semi-insulating CaN was also achieved. Ge doped GaN n-type (n up to 10(exp 20)/cu cm). P-type doping was conducted with Mg, resulting in semi-insulating layers. No yellow emission was detected from doped films. Ternary Ga(1-x)Al(x)N was grown for 0 </= x </= 1, with sharp and tailored absorption edges. Simple photoconductors were realized with GaN and Ga(1-x)Al(x)N. The lifetimes of the excess carriers were investigated. The processing of GaN and GaAlN films (deposition, annealing of contacts) was conducted. jg

Descriptors :   *ALUMINUM COMPOUNDS, *ULTRAVIOLET RADIATION, *ORGANOMETALLIC COMPOUNDS, *CHEMICAL VAPOR DEPOSITION, *NITRIDES, *PHOTODETECTORS, *GALLIUM COMPOUNDS, EMISSION, MAGNESIUM, OPTICAL PROPERTIES, LAYERS, EDGES, GROWTH(GENERAL), INSULATION, PHOTOLUMINESCENCE, X RAY DIFFRACTION, FILMS, SUBSTRATES, ELECTRON MICROSCOPY, TRANSMITTANCE, SAPPHIRE, RADIATION ABSORPTION, DOPING, N TYPE SEMICONDUCTORS, ABSORPTION, PHOTOCONDUCTORS, GERMANIUM, SILICON CARBIDES, P TYPE SEMICONDUCTORS, ELECTRON MOBILITY, METAL CONTACTS, YELLOW(COLOR).

Subject Categories : Inorganic Chemistry
      Organic Chemistry
      Physical Chemistry
      Electrooptical and Optoelectronic Devices
      Optical Detection and Detectors
      Electricity and Magnetism

Distribution Statement : APPROVED FOR PUBLIC RELEASE