Recently, Delong Laser replied to investors on the investor interaction platform that the company has completed the process research and development, testing and verification of SiC ingot slicing technology, and has obtained batch orders from top customers. This reply implies that the domestic silicon carbide industry chain has taken a position in a key field.

01

Key Technologies for Improving SiC Yield

Due to the high hardness and susceptibility to brittle cracking of SiC, ingot cutting has become the core bottleneck in SiC device manufacturing, playing a crucial role in the yield of SiC devices.

Traditional mechanical diamond blade cutting uses high-speed rotating diamond layer blades to cut SiC ingots, with a cutting track width typically ranging from 50 to 100 microns. The disadvantage of this cutting method is that as the diameter of the single crystal increases, it is necessary to replace the saw blade, which can easily cause chip fracture during this process.

In addition, once the thickness of SiC chips is less than 2mm, it is easy to cause chip cracking and increase the defect rate.

In order to improve yield, many enterprises have adopted more advanced laser cutting and cold separation technologies in recent years. Infineon acquired SiC's cold cutting technology through the acquisition of a technology company called SILTECTRA.

This technology mainly consists of two steps. The first step is to use laser irradiation to peel off the layer of the ingot, causing the internal volume of the silicon carbide material to expand, resulting in tensile stress and forming a very narrow layer of microcracks. The second step is to treat the microcracks into a main crack through polymer cooling steps, ultimately separating the wafer from the remaining ingots.

It is worth noting that SILTECTRA's cold cutting technology is the first and only one that can achieve 20-200 at the semiconductor level to date μ The technology of non-destructive cutting with thickness m covers a total of 200 patents in 70 patent families, so Infineon has taken the initiative in the key steps of SiC manufacturing after acquiring SILTECTRA.

Among Chinese enterprises, Delong Laser has a relatively early layout for SiC ingot cutting, with a maximum cutting ingot size of 8 inches, a processing time of less than 15 minutes for 6 inches, and a grinding loss of less than 50 micrometers after slicing. Previously, Delong Laser stated in research that the company currently cuts 30 wafers per ingot, which takes approximately 4-5 hours. Compared to traditional diamond wire, it can only cut 22 or 23 wafers, Delong's laser cutting efficiency has increased by about 40%.

02

Accelerated rise of domestic SiC equipment

Delong Laser has made progress in the field of laser cutting, which is a reflection of the continuous phased progress of domestic SiC equipment. With the continuous prosperity of the SiC industry, domestic SiC equipment has also been continuously improving in the past few years.

At the beginning of this year, Gazer Semiconductor stated that its independently developed and produced SiC epitaxial film thickness measurement device GS-M06Y had been officially delivered to customers. The device mainly measures the thickness of silicon epitaxial/silicon carbide epitaxial layers, has strong compatibility, can be customized based on customer needs, has shorter measurement time, and higher accuracy.

In addition, at the beginning of this year, Suzhou Baosman officially released its sintering equipment with fully independent intellectual property rights. Silver sintering is the most widely used and core technology in the third generation semiconductor packaging technology. The release of Suzhou Baosman's silver sintering equipment means that the domestic SiC production chain has taken a crucial step forward.

Last April, the SiC high-temperature epitaxial equipment independently developed by the high-power semiconductor research team of Jihua Laboratory also made breakthrough progress. Overall, domestic SiC devices are gradually emerging.