How do we get electronic grade Silicon semiconductor from sand?
Share
Lost your password? Please enter your email address. You will receive a link and will create a new password via email.
Please briefly explain why you feel this question should be reported.
Please briefly explain why you feel this answer should be reported.
Please briefly explain why you feel this user should be reported.
Using Czochralski technique we can do that. More then 90% of Si crystal prepared by this method-
Starting material for Si is pure form of sand (SiO2) called quartzite
SiO2 placed in a furnace and reacted with various forms of carbon (coal, coke)
SiC (solid) + SiO2(solid) → Si (solid) + SiO (gas) + CO (gas)
Produced metallurgical grade Si (MGS) – purity~98%
Si pulverized and treated with HCl at 300°C
Si (solid) + 3HCl (gas) → SiHCl3(gas) + H2(gas)
SiHCl3 (Trichlorosilane) is liquid at RT, and unwanted impurities are removed by the Fractional distillation method.
Purified SiHCl3 reacted with H2 and produced electronic grade Si (EGS).
SiHCl3(gas) + H2(gas) → Si (solid) + 3HCl (gas)
EGS (polycrystalline material) is raw material used to prepare single-crystal Si(device quality).