Excimer Laser Micromachining Using Binary Mask Projection for Large Area Patterning With Single Micrometer Features

Abstract

Excimer laser micromachining using binary mask projection has been investigated for rapid patterning of single micrometer features over large areas of various substrates. Simple limit for depth of focus that determines the depth to width aspect ratios is given and verified for different materials. Binary mask projection technique is found to conformally reproduce the mask features from the millimetre to the micrometer scale under proper focusing conditions. Large arrays of 1 μm and 15 μm holes on Kapton are made with high resolution and uniform periodicity. Material removal rate (MRR) for the laser machining of these holes are examined and the machining efficiency for these are found to have different dependence on the fluence. A saturation of hole-depth with increasing number of pulses is obtained.