Accession Number : AD0710812

Title :   GALLIUM ARSENIDE.

Descriptive Note : Final technical rept. 1 Mar-31 May 70,

Corporate Author : TYCO LABS INC WALTHAM MASS

Personal Author(s) : Hemmat,Naim ; Wald,Fritz

Report Date : AUG 1970

Pagination or Media Count : 31

Abstract : Because of its large band gap and high mobility, GaAs is widely used in a range of electronic and electro-optic devices. GaAs bulk crystals are produced primarily from melts using modifications of the Bridgman and Czochralski techniques. In this report, bulk crystal growth from solution is described and its advantages over other growth techniques are pointed out. In the course of the 3-month project reported here, feasibility of bulk crystal growth of GaAs from gallium-rich solution was clearly demonstrated. Four GaAs ingots up to 5 cm in length and 1 cm in diameter were produced, using the traveling heater method(THM). The preferential growth direction of GaAs for this type of growth was also determined. Due to the high cost of single crystal GaAs with suitable dimensions and orientations, seeding from single crystal seeds was not attempted. But in three experiments, growth from multigrain seeds was successfully demonstrated. The GaAs crystals grown by THM exhibited a relatively low concentration of impurities of the type generally detected in the materials prepared by other techniques. Dislocation densities in the order of 1000/sq. cm. were observed in a few of the grains for which the <111> direction coincided with the growth direction. (Author)

Descriptors :   (*GALLIUM ARSENIDES, SINGLE CRYSTALS), (*SINGLE CRYSTALS, *CRYSTAL GROWTH), FEASIBILITY STUDIES, INFRARED WINDOWS, ELECTROOPTICS, CRYSTAL DEFECTS, SOLUTIONS(MIXTURES), IMPURITIES

Subject Categories : Mfg & Industrial Eng & Control of Product Sys
      Crystallography

Distribution Statement : APPROVED FOR PUBLIC RELEASE