Ge incorporation inside 4H-SiC during homoepitaxial growth by chemical vapor deposition

Abstract

In this work, we report on the addition of GeH4 gas during homoepitaxial growth of 4H-SiC by chemical vapor deposition. Ge introduction does not affect dramatically the surface morphology and defect density though it is accompanied by Ge droplet accumulation at the surface. The Ge incorporation level inside the 4H-SiC matrix, ranging from a few 1017 to a few 1018at.cm−3, was found to be mainly affected by the growth temperature and GeH4 flux. Other growth parameters, such as C/Si ratio, polarity or off-orientation, did not show any significant influence. The Ge incorporation inside SiC was determined to occur at Si sites. On the other hand, adding GeH4 led to an increase in the intentional n-type doping level by a factor of 2–5 depending on the C/Si ratio in the gas phase.