Epitaxial Growth of 2 inch 3C-SiC on Si Substrates by Atmospheric Hot Wall CVD

摘要

As a high mobility, wide bandgap semiconductor, 3C-SiC has great promise. In this paper, we examined to obtain 3C-SiC epilayer on Si substrates using hot-wall CVD furnace and report the use of hexamethyledisilane (HMDS) and propane as reaction gases to grow uniform thickness on 2 inch (100), (111), (110) and (211) orientation of Si substrates. A horizontal atmospheric pressure CVD reactor was used. A reaction zone was specially designed. To obtain uniform thickness of the epilayer, inside of the suscceptor hole was intentionally tapered along flow direction as follows; inlet of the square hole is 13 mm x 60 mm and outlet of the hole is 7 mm x 60 mm, and laminar channel for changing the gas flow profile was managed. The susceptor was surrounded by graphite foam. Temperature of the suscepotor was measured at inside wall of the susceptor by optical pyrometer. H_2 flow rate for etching was 3 slm. An initial carbonization procedure was performed using 0.9 sccm propane at 1250℃ for 2-3 minutes. During the growth of SiC at 1300 ℃, the flow rate of HMDS was 0.75-1.2 sccm and the flow rate of propane was 0.1 - 0.5 sccm. The hydrogen carrier gas flow rate was 3-10 slm. Typical growth rate was 4.5 micron /h. Uniform thick 3C-SiC was obtained. The samples were examined using ultra violet light spectrometer and RHEED.