The booming new energy vehicle market has advanced the development process of SiC electronic control by about 2 years, but this poses a new test for the stable supply of SiC MOSFET production capacity in the automotive specification level.http://www.ic-bom.com/

From substrate to device, the overall yield of traditional silicon devices can reach up to 99%, while the highest level in the SiC industry is about 65%. The yield bottleneck in the SiC industry is mainly concentrated in the SiC single crystal process.

In the growth process of SiC single crystal, there are two main yield differences: firstly, there are very large yield differences between enterprises, with leading enterprises having yield levels as high as 50% -60%, while some new entrants have yield levels between 0% -30%. This is also the key to why there are many domestic SiC single crystal projects and few output; Secondly, there are certain fluctuations in the yield of crystals from different batches of a single enterprise, and equipment debugging and other aspects are very labor-intensive, which makes it difficult to quickly expand the production capacity of SiC single crystals.

Especially for automotive grade SiC devices, high-quality SiC substrates with low defect density and low impurities are required, which places higher demands on the stability and repeatability of the SiC single crystal growth process.http://www.ic-bom.com/

Hengpu Technology stated that the control of SiC crystal defects requires not only theoretical and engineering improvements, but also more advanced thermal field materials as support. This is because small adjustments or drifts in the thermal field inside the long crystal furnace can bring about changes in the crystal or an increase in defects, leading to greater challenges in the later stage of "growing fast, thick, and growing".

The growth of car grade SiC single crystals requires the use of advanced thermal field materials.

The mainstream growth process of SiC crystals is the PVT method, which typically sublimates and crystallizes SiC source powder in a graphite crucible at a high temperature of 2000 ℃. However, during this process, thermal field materials are prone to three problems:

The Si in SiC vapor will strongly attack graphite and release carbon particles and metal/nitrogen impurities, which will integrate into the grown SiC crystals, leading to crystal defects.

● Crucible materials such as graphite, porous graphite and tantalum carbide powder in the thermal field are prone to improper use, which will lead to the increase of carbon inclusions and other defects.

In addition, in some applications, the air permeability of porous graphite is insufficient, and additional holes need to be opened to increase the air permeability. However, porous graphite with high permeability faces challenges such as processing, powder shedding, and etching. In view of the industry‘s pain points, Hengpu Technology recently launched a new generation of SiC crystal growth thermal field material - porous tantalum carbide, achieving the world‘s first launch.http://www.ic-bom.com/

Because of the high strength and hardness of tantalum carbide, it is very difficult to process tantalum carbide into porous form. It is a great challenge to produce porous tantalum carbide with large porosity and high purity.

It is reported that through independent technical research and development, Hengpu Technology has made a breakthrough in introducing porous tantalum carbide with large porosity. The porosity can reach 75% at most, which is an international leader. In terms of the application of silicon carbide long crystal, the porous tantalum carbide of Hengpu Technology can be used for vapor component filtration, adjusting local temperature gradient, guiding the direction of material flow, controlling leakage, etc., to better assist SiC enterprises to optimize the yield of crystal.http://www.ic-bom.com/

At the same time, this porous tantalum carbide can also be combined with another solid tantalum carbide (compact) or tantalum carbide coating of Hempel Technology to form components with different local conductance, which is conducive to further improving the yield of SiC crystals.

Because tantalum carbide has high thermal stability, high purity and high chemical resistance, and can be protected from the impact of corrosive environment, some porous tantalum carbide components can be reused, greatly reducing the use cost of consumables.

The technical characteristics of this porous tantalum carbide are as follows:

Porosity ≤ 75%, internationally leading

Shape: internationally leading in sheet and tube shapes

● Uniform porosity

The improvement and stability of SiC crystal yield can help reduce the cost of SiC devices, and its stable supply can accelerate the entry of SiC devices into the market of new energy vehicles, optical storage and charging, and other fields. SiC crystals urgently need to learn from and adopt cutting-edge advanced technologies in many ways, improve the yield of crystals in the shortest time, and achieve large-scale production. The porous tantalum carbide technology of Hengpu Technology helps enterprises achieve the production goal of high yield at a faster speed.http://www.ic-bom.com/