The SIC single crystal prepared by the sublimation method will be removed from the pupa, and the wafers will be made through multiple processing processes. Figure 1 shows the general process process of wafer manufacturing. SIC single crystal (also known as SIC BOULE), first confirms its crystal direction, and then grinds outer grinding to process cylindrical crystals (sometimes called SIC PUCK). For the N -type SIC wafer for power devices, the upper and lower surfaces of the cylindrical crystals are usually {0001} planes with a deflection of 4 °. Next, a transistor orientation for a directional side or directional incision is for specified the surface of the chip surface. In large -diameter SIC wafers, directional incisions are usually tended to use. After that, the cylindrical single crystal SIC is processed into thin pieces. In most cases, the multi -line cutting method is used for slicing. Multi -wire cutting is placed between the cutting line and the SIC crystal, and the cutting line is moved to the cut. The cut SIC board needs to be flat due to uneven distribution of thickness and uneven surfaces. In the process of leveling, the bumps above micron levels above the micron level were first grinded. At this stage, due to the effect of abrasive particles, fine scratches and bumps will be left on the surface. Next, remove the unevenness below the micron level through fine processing, so that the surface can achieve the mirror effect. Compared with grinding, the abrasive particles used in polishing are smaller, and it will pay special attention during processing to avoid leaving scratches on the surface without leaving potential scars in the interior.

Figure 1: Summary of SIC wafer processing process

(A) Take the SIC crystal ingot from the 坩埚; (B) the grinding of the outer grinding; (C) to form a directional edge or directional incision; (D) multi -line cutting to form slices;

图2：晶圆边缘在磨边前后的剖面形状图

SIC is a very hard material, which is often used as abrasive particles during various materials. Therefore, it is a long and difficult process to process SIC crystal rods into wafers. It is still trying to improve.

As a new attempt for slicing processing, there are reports that use laser slices. In this technology, the laser beam is shot from the top of the cylindrical crystal, focusing on the depth of the slicing of the SIC crystal to form a modified area. Essence Generally, when cutting is used for cutting, the incision loss that cannot be ignored. At the same time, because the fluctuation of the cutting line will cause unevenness, the amount of grinding will increase, resulting in a waste of more crystal parts. In contrast, the method of slice using laser can reduce incision loss and shorten the processing time, so it is regarded as a promising technology.

In addition, as another method of slice processing, it is trying to apply voltage between metal wire and SIC crystal to generate discharge to cut, thereby reducing incision loss. This method is called metal wire discharge slice processing.

As a different way to prepare wafers from traditional SIC single crystals, there are already research reports that the SIC single -crystal film on the surface of the heterogeneous substrate (supporting the substrate) is proposed to prepare SIC wafers. Figure 3 shows the process diagram of the process of adhesion and peeling. First, hydrogen ions are injected from the surface of SIC single crystal to the peeling depth. Superimposed SIC single crystal ion injection surfaces on the flat supporting base (poly crystal SIC, etc.), and then transferred the SIC single crystal layer to the supporting substrate by pressing pressure and heating up, and then stripped. Since then, the SIC single crystal will be placed on the surface and is used again for the above bonding process. Compared with SIC single crystals, the cost of supporting the substrate is relatively low. Although there are still many problems to be resolved, the development is still underway in order to reduce the cost of wafers.

Figure 3: Press the single crystal thin film to the SIC wafer production process on the support lining