MICROANALYTICAL CHARACTERIZATION OF INCLUSIONS IN CR-DOPED LEC GAAS

Inclusions of different morphologies were observed by Infrared (IR) mi croscopy and Scanning Electron Microscopy (SEM) in the last-to-freeze region of a Cr-doped GaAs single crystal, grown by the Liquid Encapsul ated Czochralski (LEC) technique. Energy dispersive X-ray analysis (ED X) revealed that these inclusions consist of different chromium compou nds. Compositions correspond to the following binary phases and compou nds: CrGa4, Cr3As2, Cr2As3. Additionally, the quasi-ternary system of Cr3Ga4 + CrAs has been found. Sometimes, additional carbon particles h ave been detected within the heterogeneous inclusions. The possible ge neration mechanism of inclusions under supercritical growth conditions is discussed.