Luminescence Measurement of Photoresist Thickness
Original Publication Date: 1986-Nov-01
Included in the Prior Art Database: 2005-Mar-09
Photoresist luminescence can be used to measure resist thickness on rough substrates like glass-epoxy and ceramic. Low power light pulse excitation can either induce the photoresist itself or a luminescent dye dissolved in the photoresist to emit light proportional to the photoresist thickness. The required light intensities would be well below those intensities required for photoresist exposure. Organic materials luminesce (emit fluorescence or phosphorescence) when excited by utlraviolet light. For low levels of excitation, the amount of luminescence is proportional to the amount of ultraviolet light absorbed.