| 摘要 |
In processes for coating objects, such as semiconductor wafers, with a film of metal, such as titanium metal, a metal-containing compound, such as TiCl4, is injected into a chamber containing the object and a portion of the metal-containing compound reacts to provide the film of metal on the object and a gas containing by-products, such as unreacted TiCl4 and TiClx (x<4), which is discharged out of the chamber and passed through a trap mechanism and an eliminator for the removal of the by-products out of the gas. The by-products have relatively high vapor pressures, making them difficult to trap. The Applicants have found that by adding a reagent, such as water, O2 or NH3, into the exhaust gas at a location upstream of the trap mechanism and eliminator, the reagent reacts with the by-product in the gas to produce a compound, such as TiCl4.2NH3, which has a significantly lower vapor pressure than the by-product and can be removed in the trap mechanism.
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