Patent ID: 7647886

Claim:
A system for depositing material onto a workpiece in a reaction chamber, the system comprising: a reaction chamber; a mainline coupled to the reaction chamber, the mainline having a first branchline and a second branchline each downstream from the reaction chamber; a first trap in the first branchline to collect byproducts from the reaction chamber; a second trap in the second branchline to collect byproducts from the reaction chamber; a throttling valve in the second branchline; a pressure monitor to determine a pressure difference between a pressure in the mainline upstream from the first trap and a pressure in the mainline downstream from the first trap; a vacuum pump coupled to the mainline; and a controller operably coupled to the pressure monitor and the throttling valve, the controller having a computer-readable medium containing instructions that cause the controller to perform a method comprising— exhausting byproducts from the reaction chamber through the first trap in the first branchline; determining the pressure difference across the first trap caused by a flow of the byproducts by monitoring the pressure monitor; dynamically controlling the flow of byproducts into the second trap in the second branchline by regulating the throttling valve; and maintaining the pressure differential across the first trap in the mainline based on the determined pressure difference.