Laser doping of chromium as a double acceptor in silicon carbide with reduced crystalline damage and nearly all dopants in activated state

    Authors

    S. Bet; N. Quick;A. Kar

    Comments

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    Abbreviated Journal Title

    Acta Mater.

    Keywords

    silicon carbide; laser doping; chromium; DLTS; hall effect measurements; DEEP; IMPURITIES; SEMICONDUCTORS; Materials Science, Multidisciplinary; Metallurgy & Metallurgical; Engineering

    Abstract

    Chromium, a p-type dopant, has been incorporated into silicon carbide by laser doping. Secondary ion mass spectrometric data revealed enhanced solid solubility (2.29 x 10(19) cm(-3) in 6H-SiC and 1.42 x 19(19) cm(-3) in 4H-SiC), exceeding the equilibrium limit (3 x 10(17) cm(-3) in 6H-SiC above 2500 degrees C). The roughness, surface chemistry and crystalline integrity of the doped sample were examined by optical interferometry, energy dispersive X-ray spectrometry and transmission electron microscopy, respectively, and showed no crystalline disorder due to laser heating. Deep-level transient spectroscopy confirmed Cr as a deep-level acceptor with activation energies E(v) + 0.80 eV in 4H-SiC and E(v) + 0.45eV in 6H-SiC. The Hall effect measurements showed that the hole concentration (1.942 x 10(19) cm(-3)) is almost twice the average Cr concentration (1 x 10(19) cm(-3)), confirming that almost all of the Cr atoms were completely activated to the double acceptor state by the laser-doping process without requiring any additional annealing step. Published by Elsevier Ltd on behalf of Acta Materialia Inc.

    Journal Title

    Acta Materialia

    Volume

    56

    Issue/Number

    8

    Publication Date

    1-1-2008

    Document Type

    Article

    Language

    English

    First Page

    1857

    Last Page

    1867

    WOS Identifier

    WOS:000255993800021

    ISSN

    1359-6454

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