Luminescent Materials for EUV Detection Purposes

摘要

In this paper we present the results of an elaborate study to investigate the properties of luminescent materials for EUV detection in EUV lithographic tools. The study presented here involves both bulk single crystalline samples and thin film samples. Bulk single crystalline samples with polished surfaces are industrially available, while thin film samples were home-made by performing physical vapor deposition of several luminescent materials on polished quartz substrates. Careful pre-selection of these phosphors was based on multiple strong criteria. The measured results presented here include time-resolved luminescence decay, luminescence spectra and luminescence linearity measurements under deep-UV (248 nm) and extreme-UV (13.5 nm) excitation. Our results indicate the possible use of two luminescent materials, being YAG:Ce (bulk) and CaS:Ce (thin film), for EUV detection in extreme-UV lithographic tools. Practical use of these luminescent materials, however, will require high extreme-UV powers in order to obtain a sufficient signal to noise ratio.