High Purity Silicon Carbide Powder (SiC 6N 99.9999%) for Crystal Growth

Silicon carbide (SIC) is the third generation compound semiconductor material. Chip is the cornerstone of the semiconductor industry. According to the historical process, the core materials for making chips are divided into the first generation of semiconductor materials (most of which are high-purity silicon widely used at present), the second generation of compound semiconductor materials (gallium arsenide and indium phosphide), and the third generation of compound semiconductor materials (silicon carbide and gallium nitride). Silicon carbide will be the most widely used basic material for making semiconductor chips in the future because of its superior physical properties: high band gap (corresponding to high breakdown electric field and high power density), high conductivity and high thermal conductivity.

The main form of SiC in semiconductor chip is substrate. Semiconductor chips are divided into integrated circuits and discrete devices, but the basic structure of both integrated circuits and discrete devices can be divided into "substrate epitaxy device" structure. The main form of silicon carbide in semiconductors is as a substrate material. Silicon carbide wafer is a single crystal wafer formed by cutting, grinding, polishing and cleaning of silicon carbide crystal. Silicon carbide wafer as a semiconductor substrate material, through epitaxial growth, device manufacturing and other links, can be made into silicon carbide based power devices and microwave RF devices. It is an important basic material for the development of the third generation semiconductor industry.

Silicon Carbide Processing Process:
Silicon carbide wafer is made of high-purity silicon powder and high-purity carbon powder as raw materials. Silicon carbide crystal is grown by physical vapor transport (PVT) method and processed into silicon carbide wafer.

① Raw Material Synthesis

Silicon carbide particles were synthesized by mixing high-purity silicon powder and high-purity carbon powder in a certain proportion at a high temperature above 2000 ℃. After crushing, cleaning and other processes, high-purity silicon carbide powder raw materials meeting the requirements of crystal growth were prepared.

② Crystal Growth

Using high purity silicon carbide powder as raw material, silicon carbide crystal was grown by PVT method in a self-developed crystal growth furnace. High purity silicon carbide powder and seed crystal were placed in the bottom and top of cylindrical closed graphite crucible in single crystal growth furnace, respectively. The crucible was heated to above 2000 ℃ by electromagnetic induction, and the temperature of seed crystal was controlled to be slightly lower than that of lower powder, forming an axial temperature gradient in the crucible. Silicon carbide powder sublimates at high temperature to form gaseous si2c, sic2, Si and other substances. Driven by temperature gradient, it reaches the seed crystal with lower temperature and crystallizes on it to form cylindrical silicon carbide ingot.

③ Ingot Processing

The silicon carbide ingot was oriented by X-ray single crystal orientation instrument, then ground and rolled to produce silicon carbide crystal with standard diameter.

④ Crystal Cutting

Using multi wire cutting equipment, the silicon carbide crystal is cut into thin sheet with thickness less than 1 mm.

⑤ Wafer Grinding

The wafer is ground to the required flatness and roughness by diamond grinding fluid with different particle sizes.

⑥ Wafer Polishing

Through mechanical polishing and chemical mechanical polishing, the silicon carbide polished wafers with no surface damage were obtained.

⑦ Wafer Inspection

Optical microscope, X-ray diffractometer, atomic force microscope, non-contact resistivity tester, surface flatness tester, surface defect tester and other instruments and equipment were used to detect the micro tube density, crystal quality, surface roughness, resistivity, warpage, curvature, thickness change, surface scratch and other parameters of silicon carbide wafer, According to this, the quality grade of the wafer can be determined.

⑧ Wafer Cleaning

The silicon carbide polishing wafer was cleaned with cleaning agent and pure water to remove the residual polishing liquid and other surface dirt on the polishing wafer, and then the wafer was dried by ultra-high purity nitrogen and dryer; The wafer is packaged in a clean cartridge in a super clean room to form a silicon carbide wafer that can be used immediately downstream.

High Purity Silicon Carbide Powder for Crystal Growth

In order to make SiC crystal, it is necessary to use SiC powder for crystal growth. High purity silicon carbide powder for crystal growth is a kind of high purity silicon carbide powder as raw material, using crystal growth furnace, using physical vapor transport (PVT) method to grow silicon carbide crystal.

FUS NANO can provide high purity silicon carbide powder for crystal growth in batches. The purity is 6N 99.9999%. It can meet the needs of SiC crystal growth. It is suitable for silicon carbide single crystal growth raw materials, precision silicon carbide ceramic parts in semiconductor equipment and LED equipment, etc.