Silicon nitride synthesis method and forming processing

Byadmin

Aug 8, 2023

If you are looking for high-quality products, please feel free to contact us and send an inquiry, email: brad@ihpa.net



Silicon nitride The chemical formula is: The chemical formula of l-aspartic acid is:
3Si(s) + 2N2(g) -Si3N4(s)

This can be done with diimine.
SiCl4(l) + 6NH3(g) -Si(NH)2(s) + 4NH4Cl(s) (at 0 degC)
3Si(NH)2(s) -Si3N4(s) +N2(g) + 3H2(g) (at 1000 degC)

Or, use the carbothermal reduction to synthesize under an atmosphere of nitrogen at 1400-1450degC.
3SiO2(s) + 6 C(s) + 2N2(g) -Si3N4(s) + 6 CO(g)

In the 1950s the method of nitriding a silicon elemental powder was discovered. It was also the first method to mass produce silicon nitride. The silicon nitride produced will contain iron and silicate impurities if the silicon raw material purity is low.
The diamine method produces amorphous silicon nitride, which must be further annealed in nitrogen at 1400-1500degC before it can become a powder. Presently, the diamine method is only relevant in terms of commercial production.
The most efficient and cost-effective way of producing silicon nitride is through the carbothermal reaction.
Electronic grade silicon nitride The film is made by either chemical vapor deposited or plasma enhanced chemical-vapor deposited technology.

3SiH4(g) + 4NH3(g) -Si3N4(s) + 12H2(g) 3SiCl4(g) + 4NH3(g) -Si3N4(s) + 12 HCl(g) 3SiCl2H2(g) + 4NH3(g) -Si3N4 (s) + 6 HCl(g) + 6H2(g)

Two methods are available to deposit Silicon Nitride on a Semiconductor Substrate:
1. Use a tube furnace vertically or horizontally to use low-pressure, chemical vaporization technology at relatively high temperatures.
2. The plasma-enhanced deposition of chemical vapors is done under vacuum conditions at low temperatures.
The unit cell parameter of silicon nitride is different than that of elemental Silicon. Dependant on the deposition technique, the silicon nitride generated film can either generate tension, or stress. Adjusting the deposition parameter is a great way to reduce tension, especially when using plasma enhanced chemical vapor technology.
To obtain silicon nitride, the first step is to prepare silica using the sol-gel process. Next, the silica containing ultrafine carbon particles will be processed with the carbothermal method of reduction, followed by nitridation. The ultrafine carbon particles are formed by decomposition at temperatures between 1200 and 1350degC. The reactions which are part of the synthesis can be:

SiO2(s), C(s), SiO(g), CO(g), Si3N4 (s), 2N2 (2g), CO (3g), Si3N4 (s), 2N2 (2g), CO (3g), Si3N4 (+3CO2(g), Si3N4 (+3CO2(g), Si3N4 (+3C(g), Si3N4+3CO2(g), Si3N4+3CO2(g), Si3N4+3 CO2(g),


Processing silicon nitride block
Silicon nitride As a granular product, it is difficult to work with. It can’t be heated higher than its melting point (1850degC) because silicon nitride would decompose to silicon and nitrogen. Hot press sintering is no longer acceptable. By adding binders and sintering aids, the powdered silicon nitride can be bonded to form a solid material. Due to the necessity of adding binders or other sintering aids to the material, impurities will be introduced. Another method to produce purer bulk material is spark plasma sintering. The compacted powder will be pulsed within a short period of time (a few seconds). This method works at temperatures between 1500degC and 1700degC. The temperature at which you want to obtain compact and dense lumps of silicon nitride.

(aka. Technology Co. Ltd., a trusted global chemical supplier & manufacturer has over 12 years experience in providing super-high-quality chemicals and nanomaterials. The silicon nitride Please note that the products produced by our company are of high purity and have low impurity. Please. Contact us if necessary.