A plastic-fibre-bundle-based transducer array for mapping and detectionof the end point for dissolution of a photoresist

Abstract

Dynamical mapping of the development of a photoresist by use of atwo-dimensional plastic-optical-fibre-bundle (POFB)-based transducer array isdemonstrated in this work. The performance of a lens-free POFB transducer forin situ detection of the end point of the development of a photoresistis discussed. An improved optical collecting efficiency of up to 5-6 dB undera normal-detection scheme is achieved. The dissolution rate and thickness canbe temporally resolved by this system with a standard deviation of less than1.5%. The noise-equivalent power of the POFB transducer is as small as100 nW Hz-1/2 with the use of a modulated laser source.