In this paper an overview is given on the current state of epitaxial growth of SiC with special regard to our work at SIEMENS CRD. Problems concerning impurity incorporation and ways to achieve background doping levels as low as 1014 cm−3 are discussed as well as the influence of high speed wafer rotation on the gas flow in our reactor and related effects on uniformity in thickness and doping. Precise control of the C/Si ratio in the gas phase, which is easily achieved in the described reactor, and the use of reduced pressure lead to a good control of dopant incorporation over more than 3 orders of magnitude while maintaining smooth surface morphology even at growth rates higher than 5 μm/h. Doping variations <±8 % across 30 mm wafers can routinely be obtained. The quality of the egilayers is proven by electrical breakdown fields as high as 2*106 V/cm at NA−ND=5* 10−15 cm−and an electron mobility greater than 700 cm2 /Vs at 300 K (4H-SiC).
Finally it is demonstrated that the gas composition at the end of the epitaxial growth process is an important step in order to get oxygen resistant surface properties for subsequent device processing.