Backside Detection of Photoresist Development Endpoint Using Surface Plasmon Resonance

Simulations and experiments done for a simple photoresist on metallized glass wafer structure show that surface plasmon resonance, a method commonly used in biosensing, is suitable for monitoring photoresist development. End-point can be detected very easily and according to simulations, the detection sensitivity is highest close to the endpoint, which indicates high potential for closer study of development process even down to monolayer thicknesses. The method allows instrumentation to be placed on the backside of the wafer leaving the photoresist development process undisturbed.