Active
Carbon Control During VGF Growth of Semiinsulating GaAs
T.
Bünger, J. Stenzenberger, F. Börner, U. Kretzer,
R.
Bindemann, B. Weinert, S. Teichert, T. Flade
Freiberger
Compound Materials GmbH, Am Junger Löwe Schacht 5, 09599
*Corresponding
author, phone: +49-3731-280-248, fax: +49-3731-280-106,
email: buenger@fcm-germany.com
Keywords: VGF,
semi-insulating, carbon control
INTRODUCTION
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 [1]. 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.