Factors affecting the formation of misoriented domains in 6H‐SiC single crystals grown by PVT method

Abstract

Misoriented domains (MDs) are common defects in 6H-SiC single crystals. We performed an experimental study on the formation of MDs in 2-inch 6H-SiC single crystals. Micro-Raman spectroscopy revealed that the polytype of MDs was mainly 4H-SiC. By changing growth conditions, it was found that the MDs' formation was closely related to growth rate and the position of highest temperature relative to growth interface. When the growth rate of ingots was relatively high the MDs were more likely to form. Furthermore, the nearer growth interface the position of highest temperature was, the larger the size of the MDs. Based on our experimental findings we suggested that the MDs' formation and the polytype switching from 6H-to 4H-SiC were due to too large axial and/or radial temperature gradients.The results would be helpful to improve the quality of SiC single crystals grown by PVT technique.

Debye temperature of 4H-SiC determined by X-ray powder diffraction

“…Nonintentional doped 4 H -SiC single crystals were grown by PVT in our laboratory, and details have been reported elsewhere (Li et al , 2003, 2004; Peng et al , 2009). A wafer sliced from a crystal boule was first examined by Raman scattering.…”

Synthesis and Growth of 6H-SiC and 3C-SiC in an Al–Si–C System at 820 °C: Effect of the Reaction Path on the SiC Polytype

“…Growth parameters like temperature, pressure, and supersaturation have a strong influence on the SiC polytype during the physical vapor transport (PVT) process. By adjusting these three factors, the growth characteristics of 4H and 6H SiC can be changed, and the transition between 4H-SiC and 6H-SiC can also be observed. − Other factors such as impurities, surface types, offsets of the substrate, and atmospheric conditions are also important for the synthesis of SiC with a specific polytype in the PVT method. − For SiC obtained by the chemical vapor deposition (CVD) method, 3C-SiC is the typical polytype . However, by proper selection of precursor and controlled synthesis parameters, 2H-SiC, 4H-SiC, and 6H-SiC can also be obtained. − During the CVD process, the SiC polytype has a close relationship with the silicon-to-carbon (Si/C) ratio.…”

Characterizations and formation mechanism of a new type of defect related to nitrogen doping in SiC crystals

“…On top of these, SiC single crystal is attractive for being the substrate in the heteroepitaxial growth of other important materials [5][6][7]. These applications require polytypic stable, large diameter SiC single crystals with low density of defects including micropipes, voids, dislocations, domains and stacking faults [8][9][10][11][12][13][14][15][16][17][18][19]. However, there are still issues need to be addressed in order to meet the increasing demands of high quality in some specific fields of applications.…”