Patent ID: 7459175
Filing Date: 2008-12-02
Classification: C23C

Abstract:
1. A method of operating a monolayer deposition (MLD) processing system comprising: positioning a plurality of wafers in a processing chamber, each having a surface; determining a plurality of surface saturation zones on the surface of at least one of the plurality of wafers; creating a first virtual sensor to estimate a surface saturation state value for one or more of the plurality of surface saturation zones; establishing a desired surface saturation state value for the one or more of the plurality of surface saturation zones; performing a first deposition process during a first process time, including exposing the plurality of wafers to a first precursor-containing gas comprising first precursor molecules until the estimated surface saturation state value from the first virtual sensor is approximately equal to the desired surface saturation state value, and thereby depositing a substantially uniform film of first precursor molecules onto the surfaces of the plurality of wafers; creating a dynamic model of the first deposition process, the dynamic model having model components (M obtaining data for the at least one control input (U) and the at least one measured output (Y); determining an estimated value (D determining an estimated value (Z flowing the first precursor-containing gas into the processing chamber at a first gas flow rate, wherein the at least one control input (U) comprises the first gas flow rate; modeling the flow of the first precursor molecules within the processing chamber; modeling flow between the wafers as a diffusion process; determining a residence time for the first precursor molecules; determining a desired precursor concentration level for the one or more of the plurality of surface saturation zones; determining a chemisorption rate for the one or more of the plurality of surface saturation zones; estimating a precursor concentration level for the one or more of the plurality of surface saturation zones, wherein the at least one regulated output (Z) comprises the first virtual sensor for estimating the precursor concentration level; and flowing the first precursor-containing gas into the process chamber until the estimated precursor concentration level is approximately equal to the desired precursor concentration level.