Could we discuss the key control points for producing polysilicon using Siemens’ improved method?
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The several key stages in the production of polysilicon using Siemens’ improved method are discussed separately
For example: the reduction furnace has specific requirements regarding the molar ratio of hydrogen to trichlorosilane; therefore, high-precision mass flow meters should be used for measurement, and formulation control should be employed for regulation. I would appreciate any advice from everyone
TCS purity, especially the purity of P and L hydrogen. . .
How should the gas flow rate be controlled at various stages of the reduction reaction? It shouldn’t remain unchanged all the time
Regarding the issue of air intake into the furnace, there are two different opinions: one is to continuously increase the feed until the furnace is shut down. Another approach is to maintain the feed rate at a certain value until the furnace is shut down. Let’s discuss how each of you controls the flow rate of your feed materials
In the production of polysilicon using Siemens’ improved method, it seems that the key lies in the control of exhaust gas recovery; the other aspects of this technology are already quite mature. Controlling exhaust gas recovery well also reduces costs, which is highly beneficial for increasing competition in the market
Chlorination process to increase the conversion rate of silicon tetrachloride； Reduction: control the feed molar ratio, as well as the pressure and temperature inside the furnace.
Those who work on exhaust gas recovery units. Temperature and pressure of the distillation tower. Temperature, pressure, and time of the adsorption tower.
7# wsyghnnyr While the exhaust gas recovery system is indeed important, it would be inaccurate to say that all other aspects are already mature. Take the reduction process as an example – there are several key issues that need to be addressed: increasing the deposition rate and reducing power consumption, solving gas dynamics problems, and optimizing the design of bell-jar reactors. If these problems are solved, the silicon that is deposited will be quite sharp. Research on polysilicon technology in our country needs to be strengthened urgently; it cannot be improved in just a day or two.
Gentlemen, if we are to talk about the key points of control, it’s not enough to just ensure that one particular process is well controlled. For example, even if hydrogenation reduction is controlled perfectly, will that improve the purity of the product? Therefore, from the very beginning, it is necessary to strictly control the process parameters for the TCS synthesis process, distillation process, hydrogenation reduction process, exhaust gas recovery process, as well as various auxiliary processes (involving water and gas), in order to ensure product quality and improve product purity and efficiency.