Growth Facet

Growth Facet

What is the Growth Facet?

In the central region of SiC {0001} wafer, the doping concentration is usually relatively high, such as the dark color observed in the central region, which is due to the enhanced impurity doping in facet growth, as shown in Fig. 1 and Fig.2. In the process of sublimation growth, a {0001} facet will appear near the center of the ingot, and rapid spiral growth will occur on the {0001} facet, but the growth rate along the < 0001 > direction is relatively low. Therefore, impurity doping is enhanced in the small plane region of (0001). Therefore, the doping concentration in the central region (facet region) of the wafer is usually 20% ~ 50% higher than that in the peripheral region of the wafer.

 

 

 

 

 

 

 

 

 

Fig.1: the facets showing clear hexagon steps by the optical profiling system.

 

 

 

 

 

 

 

 

Fig.2: 3D and cross-section distributions of 4H and 6H polytypes in a 3-inch SiC ingot using CT image processing software. The insert at the bottom right corner is the polytype distribution image of one wafer using Raman mapping.

In a book name: Fundamentals of Silicon Carbide Technology: Growth, Characterization, Devices, and Applications written by Tsunenobu Kimoto(Japan) and James A.Cooper(US), it also explain growth facet affect color difference in 3.4.1 Impurities Doped at Growth of Silicon Carbide Ingots of Chapter 3.

We also show you picture of regular Silicon carbide, you can see the color difference because of growth facet:

picture of regular Silicon carbide

Does Growth Face Affect Usage?

Every wafer has growth facet, just in different area or different place or color light or heavy, but growth facet and without growth facet area has a little different color, which do not effect any your application.

 

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For more information, please contact us email at victorchan@powerwaywafer.com and powerwaymaterial@gmail.com.

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