Active Carbon Control During VGF Growth of Semiinsulating GaAs
Bünger, J. Stenzenberger, F. Börner, U. Kretzer,
R. Bindemann, B. Weinert, S. Teichert, T. Flade
Compound Materials GmbH, Am Junger Löwe Schacht 5, 09599
*Corresponding author, phone: +49-3731-280-248, fax: +49-3731-280-106,
Keywords: VGF, semi-insulating, carbon control
Today the III/V compound semiconductor industry uses GaAs substrates grown by different crystal growth technologies. A leading substrate supplier has to provide customer specific GaAs wafers made of crystals grown by these different technologies. The device industry requires substrate wafers with exactly tailored properties. One main parameter of interest is the electrical resistivity of semi-insulating GaAs. The homogeneity of this parameter within a wafer (radial homogeneity) and from wafer to wafer within an ingot (axial homogeneity) is especially challenging for substrate production. State-of-the-art Lec material shows excellent electrical properties by using active carbon control during the crystal growth process . However, the production process for low EPD material requires an adjusted strategy to obtain results similar to those reached in the Lec process. In this paper we report on our active carbon control during VGF crystal growth.