Title

Effect of laser field and thermal stress on diffusion in laser doping of SiC

Authors

Authors

S. Bet; N. Quick;A. Kar

Comments

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Abbreviated Journal Title

Acta Mater.

Keywords

SiC; chromium; laser doping; diffusion; SIMS; SILICON-CARBIDE; ENHANCED DIFFUSION; IMPURITIES; Materials Science, Multidisciplinary; Metallurgy & Metallurgical; Engineering

Abstract

The electromagnetic field of lasers and non-equilibrium doping conditions enable laser doping of SiC with increased dopant diffusivity. Chromium, which acts as a double acceptor, has been laser-doped in SiC wafers. A thermal model is utilized to determine the temperature distribution at various depths of the wafer and a diffusion model is presented including the effects of Fickian diffusion, laser electromagnetic field and thermal stresses due to localized laser heating on the mass flux of dopant atoms. The dopant diffusivity is calculated as a function of temperature at different depths of the wafer based on measured dopant concentration profile. The maximum diffusivities achieved in this study are 4.61 x 10(-10) cm(2) s(-1) at 2898 K and 6.92 x 10(-12) cm(2) s(-1) at 3046 K for 6H-SiC and 4H-SiC, respectively. The maximum concentration is found to be 2.29 x 10(19) cm(-3) for 6H-SiC, which is two orders of magnitude higher than the reported value (3 x 10(17) cm(-3) solid solubility limit). Published by Elsevier Ltd on behalf of Acta Materialia Inc.

Journal Title

Acta Materialia

Volume

55

Issue/Number

20

Publication Date

1-1-2007

Document Type

Article

Language

English

First Page

6816

Last Page

6824

WOS Identifier

WOS:000251668500015

ISSN

1359-6454

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