Quantitative measurement of gas phase process intermediates using raman spectroscopy

A method for quantitatively monitoring gas phase materials in a process for making high purity silicon comprising:

• providing a gaseous feed stream containing comprising one or more reactant gases of interest;
• exposing said gaseous feed stream to radiation from a Raman spectroscopic device;
• acquiring a Raman spectroscopic signal from each of the gaseous components in said feed stream;
• analyzing said spectroscopic signal to determine the presence and concentration of each of said gaseous components;
• and
• displaying the results of said analysis.

A method for producing high purity polycrystalline silicon comprising,

• providing a gaseous feed stream containing H2, and at least one silane selected from SiH4, H3SiCl, HSiCl3, H2SiCl2, or SiCl4;
• reacting the components of said gaseous feed stream to form high purity polycrystalline silicon;
• contemporaneously with the reaction, monitoring the gases in said gaseous feed stream by,
• exposing said gaseous feed stream to radiation from a Raman spectroscopic device;
• acquiring a Raman spectroscopic signal from each of the gaseous components in said feed stream;
• analyzing said spectroscopic signal to determine the presence and concentration of each of said gaseous components and to detect any deviations from predetermined values for each of said gaseous components;
• and
• adjusting the feed rate of any of said gaseous components that deviate from said predetermined values.

A method for quantitatively monitoring gas phase materials in a process for hydrogenating silicon tetrachloride to form at least one of trichlorosilane and dichlorosilane comprising:

• providing a gaseous feed stream containing H2 and SiCl4;
• exposing said gaseous feed stream to radiation from a Raman spectroscopic device;
• acquiring a Raman spectroscopic signal from each of the gaseous components in said feed stream;
• analyzing said spectroscopic signal to determine the presence and concentration of each of said gaseous components;
• and
• displaying the results of said analysis.