Dislocations in 6H-SiC and their influence on electrical properties of n-type crystals^*

¹ Laboratoire de Métallurgie Physique (UMR 6630 CNRS), Université de Poitiers, Bd3-Téléport 2, 86960 Futuroscope Cedex, France
² Department of Materials Science and Engineering, Case Western Reserve University, Cleveland, OH 44106, USA

Corresponding author: Jean-Francois.Barbot@lmp.univ-poitiers.fr

Received: 28 October 1997
Accepted: 20 February 1998
Published online: 15 May 1998

Abstract

By scratching the (0001)Si surface of 6H-SiC followed by annealing, dislocations were introduced in the crystal that were subsequently characterized by Transmission Electron Microscopy (TEM). Schottky diodes were then manufactured from the dislocated crystal and their electrical properties were studied by capacitance-voltage (C−V), current-voltage (I−V), and thermally-stimulated capacitance (TSCap) measurements. It was found that the deformation introduces deep traps Maynly located in the upper third of the bandgap promoting a significant increase in the series resistance of the diodes. The as-introduced dislocations were predominantly 30° partials and their core nature was determined to be Si(g) by the technique of Large Angle Convergent Beam Electron Diffraction (LACBED). The compensation effects observed after deformation are presumed to be caused not only by Si(g) dislocations but also by the other defects generated during the deformation step.