Accession Number : ADA260573


Title :   Fundamental and Applied Aspects of Defect Engineering in GaAs


Descriptive Note : Final rept. 12 Jan 1990-30 Sep 1992


Corporate Author : UNIVERSITY OF SOUTH FLORIDA TAMPA


Personal Author(s) : Lagowski, Jacek


Full Text : https://apps.dtic.mil/dtic/tr/fulltext/u2/a260573.pdf


Report Date : 08 Dec 1992


Pagination or Media Count : 20


Abstract : The program was aimed at advancing the fundamental and applied knowledge required for defect engineering in bulk GaAs. It was focussed on deep level defects, especially antisite defects such as arsenic-antisite related EL2 defect and gallium antisite acceptor defects. Using non-stoichiometric crystal methods, with controlled cooling rates, we established, for the first time, quantitative temperature characteristics of the EL2 formation rate. We determined melt stoichiometry and Fermi energy dependence of the native acceptor concentration. The latter results has stimulated theoretical interest and ab initio calculations by the Xerox group of the negative 'U' property of the Ga sub As antisite. Recently we also completed a study on the hetero-antisite defect, Sb sub Ga. Using our knowledge of EL2 formation/annihilation, we were able to engineer defect structure in arsenic-rich crystal leading to very low EL2 and EL3 concentrations. This enabled the first positive identification of both, single and double levels of SbGA defect otherwise marked by the EL2 and EL3 defects. The program has also lead to the discovery of a non-contract, no preparation, wafer scale, deep level defect characterization method based on the surface photo voltage transient.


Descriptors :   *CRYSTAL DEFECTS , *GALLIUM ARSENIDES , CRYSTALS , ENGINEERING , IDENTIFICATION , MELTS , RATES , STOICHIOMETRY , STRUCTURES , SURFACES , TRANSIENTS , VACANCIES(CRYSTAL DEFECTS) , WAFERS


Subject Categories : Crystallography


Distribution Statement : APPROVED FOR PUBLIC RELEASE