Growth of 3C-SiC on 150-mm Si(100) substrates by alternating supply epitaxy at 1000 °C

To lower deposition temperature and reduce thermal mismatch induced stress, heteroepitaxial growth of single-crystalline 3C-SiC on 150 mm Si wafers was investigated at 1000 degrees C using alternating supply epitaxy. The growth was performed in a hot-wall low-pressure chemical vapor deposition reactor, with silane and acetylene being employed as precursors. To avoid contamination of Si substrate, the reactor was filled in with oxygen to grow silicon dioxide, and then this thin oxide layer was etched away by silane, followed by a carbonization step performed at 750 degrees C before the temperature was ramped up to 1000 degrees C to start the growth of SiC. Microstructure analyses demonstrated that single-crystalline 3C-SiC is epitaxially grown on Si substrate and the film quality is improved as thickness increases. The growth rate varied from 0.44 to 0.76 +/- 0.02 nm/cycle by adjusting the supply volume of SiH(4) and C(2)H(2). The thickness nonuniformity across wafer was controlled with +/- 1%. For a prime grade 150 mm virgin Si(100) wafer, the bow increased from 2.1 to 3.1 mu m after 960 nm SiC film was deposited. The SiC films are naturally n type conductivity as characterized by the hot-probe technique. (C) 2011 Elsevier B.V. All rights reserved.