Reduction of structural defects in thick 4H-SiC epitaxial layers grown on 4° off-axis substrates
2013 (English)In: Journal of Applied Physics, ISSN 0021-8979, E-ISSN 1089-7550, Vol. 113, no 22Article in journal (Refereed) Published
By carefully controlling the surface chemistry of the chemical vapor deposition process for silicon carbide (SiC), 100 μm thick epitaxial layers with excellent morphology were grown on 4° off-axis SiC substrates at growth rates exceeding 100 μm/h. In order to reduce the formation of step bunching and structural defects, mainly triangular defects, the effect of varying parameters such as growth temperature, C/Si ratio, Cl/Si ratio, Si/H2 ratio, and in situ pre-growth surface etching time are studied. It was found that an in-situ pre growth etch at growth temperature and pressure using 0.6% HCl in hydrogen for 12 min reduced the structural defects by etching preferentially on surface damages of the substrate surface. By then applying a slightly lower growth temperature of 1575 °C, a C/Si ratio of 0.8, and a Cl/Si ratio of 5, 100 μm thick, step-bunch free epitaxial layer with a minimum triangular defect density and excellent morphology could be grown, thus enabling SiC power device structures to be grown on 4° off axis SiC substrates.
Place, publisher, year, edition, pages
American Institute of Physics (AIP) , 2013. Vol. 113, no 22
Engineering and Technology
IdentifiersURN: urn:nbn:se:liu:diva-96469DOI: 10.1063/1.4809928ISI: 000320675300004OAI: oai:DiVA.org:liu-96469DiVA: diva2:642921