High growth rate of 4H-SiC epilayers grown on on-axis substrates with different chlorinated precursors
2010 (English)In: Crystal Growth & Design, ISSN 1528-7483, E-ISSN 1528-7505, Vol. 10, no 12, 5334-5340 p.Article in journal (Refereed) Published
The epitaxial growth of 4H-SiC on on-axis substrates is a very important process to develop in order to accelerate the development and improve the performance of bipolar SiC based power devices, but until now, only relatively low growth rate processes have been demonstrated. The aim of this study is to demonstrate a high growth rate deposition process of high quality 4H-SiC epilayers on on-axis substrates, free of 3C-SiC inclusions. Previous studies showed that silicon-rich gas-phase conditions (prior to, and during the deposition process) and/or high Cl/Si ratios were vital in order to avoid 3C-SiC inclusions in the epitaxial layers when growing on on-axis substrates. This study combines the knowledge of surface pre-treatment with the chloride-based chemistry developed for off-axis growth. Two different precursor approaches were used, one adopting the standard precursors (silane and ethylene) with addition of hydrogen chloride (HCl), and the other based on the molecule methyltrichlorosilane (CH3SiCl3 or MTS). In this study we will show that using a MTS-based CVD process in combination with proper in situ silane etching and accurate optimisation of the other process parameters (temperature, C/Si and Cl/Si ratio) results in homoepitaxial growth of high purity and high quality 4H-SiC layers on on-axis Si-face substrates at a growth rate of 100 μm/h. Additionally, a higher efficiency of the MTS precursor chemistry was found and discussed.
Place, publisher, year, edition, pages
American Chemical Society , 2010. Vol. 10, no 12, 5334-5340 p.
IdentifiersURN: urn:nbn:se:liu:diva-60216DOI: 10.1021/cg101288uISI: 000284675100045OAI: oai:DiVA.org:liu-60216DiVA: diva2:355735