Patent ID: 8182861

Claim:
A method for monitoring processing of a thin film on a substrate, said method comprising the steps of: providing a thin film deposition source for generating a flux of precursors, wherein said flux of precursors is generated in a flux region, providing said substrate having a receiving surface for receiving said precursors; providing a sensor having a sensing surface for receiving said precursors; translating said substrate in said flux region, wherein translation of said substrate moves said receiving surface along a receiving surface trajectory in said flux region, thereby generating said thin film on said receiving surface of said substrate; translating said sensor in said flux region, wherein translation of said sensor moves said sensing surface along a sensing surface trajectory in said flux region that is substantially coincident to said receiving surface trajectory, thereby generating a thin film on said sensing surface of said sensor; and measuring a physical, optical or chemical property of said thin film on said sensing surface of said sensor, thereby monitoring processing of said thin film on said substrate; wherein said sensing surface trajectory and said receiving surface trajectory are substantially coincident when: [ 〈 ( T P ⇀ ⁢ Sensing ⁡ ( t , t + Δ ⁢ ⁢ t ) - T P ⇀ ⁢ Receiving ⁡ ( t , t + Δ ⁢ ⁢ t ) T P ⇀ ⁢ Receiving ⁡ ( t , t + Δ ⁢ ⁢ t ) ) 2 〉 t ] ⁢ 1 / 2 < A , wherein A is a tolerance in fractional accuracy of a layer thickness of precursors deposited on said receiving surface over a selected time scale, Δt, and T {right arrow over (P)}Sensing (t, t+Δt) and T {right arrow over (P)}Receiving (t, t+Δt) are time dependent process source thickness factors for said sensing and receiving surfaces, respectively.