Possibility for the electrical activation of the carbon antisite by hydrogen in SiC
2005 (English)Article in journal (Refereed) Published
Calculations predict the carbon antisite to be the most abundant intrinsic defect in silicon carbide in a wide range of doping. The isolated carbon antisite is, however, optically and electronically inactive, therefore, difficult to observe by usual experimental techniques. However, CSi can trap mobile impurities forming electrically active complexes. We will show by ab initio supercell calculations that the hydrogen interstitial is trapped by the carbon antisite forming an electrically active defect which might be detectable by different spectroscopic techniques. The key to activate C Si by hydrogen is to introduce sufficient amount of hydrogen in the SiC samples and to avoid formation of vacancies or boron-hydrogen complexes. We have found that the concentration of CSi+H complex is above 10 13 cm-3 in highly doped p-type chemical vapor deposited (CVD) layers as well as in highly doped p-type and n-type SiC samples annealed in high temperature high pressure (HTHP) H2 gas. The concentration of CSi+H complex can be enhanced in Al-doped CVD and HTHP SiC samples by applying the appropriate post-annealing temperature. The CSi+H complex might be also detected in Al-doped SiC samples irradiated at room temperature by low energy H2+ ions. ©2005 The American Physical Society.
Place, publisher, year, edition, pages
2005. Vol. 71, no 3
IdentifiersURN: urn:nbn:se:liu:diva-30691DOI: 10.1103/PhysRevB.71.035213Local ID: 16299OAI: oai:DiVA.org:liu-30691DiVA: diva2:251514