Tetrachlorosilane (SiCl 4 ) gas is reacted with hydrogen gas (H 2 ) to produce electronic-grade polycrystalline
Question:
Tetrachlorosilane (SiCl4) gas is reacted with hydrogen gas (H2) to produce electronic-grade polycrystalline silicon at 800°C and 1.5 × 105 Pa according to the reaction equation:
SiCl4(g) + 2H2(g) → Si(s) + 4HCl(g).
The reaction rate may experience diffusion limitations at the growing Si solid surface. To address this concern, the diffusion coefficient coefficients in this system must be estimated.
a. Estimate the binary diffusion coefficient of SiCl4 in H2 gas.
b. Estimate the diffusion coefficient of SiCl4 in a mixture containing 40 mole% SiCl4, 40 mole% H2, and 20 mole% HCl. Is this diffusion coefficient substantively different than the diffusion coefficient estimated in part (a)? The Lennard–Jones parameters for SiCl4 are σ = 5.08 Å and ε/k = 358 K.
Step by Step Answer:
Fundamentals Of Momentum Heat And Mass Transfer
ISBN: 9781118947463
6th Edition
Authors: James Welty, Gregory L. Rorrer, David G. Foster