Modeling of Poly-SiC Deposits in PVT SiC
One of the key problems in SiC crystal growth by PVT is deposition of poly-SiC material. It is most commonly observed at the edge of the crucible. However, poly-SiC formation in some cases may reduce the efficiency of the source operation as well. Most importantly, the deposits can cause the increase of mechanical stresses in the crystal which, in turn, can be detrimental for the crystal quality.
To address these issues, VR has models that allow identification of growth conditions favorable for the formation polycrystalline material. Therefore, it can be used to assess the likelihood of parasitic deposition at certain part of the growth crucible and expected deposition rate. Thus, simulation can be used to estimate the shape of the deposit at each time step of the long-term growth. Using VR the user can try different hot zone designs and growth conditions to minimize parasitic deposition of poly-SiC.