Maskless patterning of indium tin oxide layer for flat panel displays by diode-pumped Nd:YLF laser irradiation

Abstract

An indium tin oxide (ITO) layer on a lime glass substrate for flat panel displays has been patterned without a mask by scanning Nd:YLF (neodymium-doped yttrium-lithium-fluoride) laser irradiation in a pulsed mode. Both fundamental and frequency doubled lines of 1.047 μm and 523.5 nm were compared for processing. SEM (scanning electron microscopy) and surface stylus observation revealed that only the top ITO layer could be removed without substrate etching. A finer patterning was possible for irradiation of a 523.5 nm line because of the better focusing feature, though higher laser energy density was required for this line than for a 1.047 μm line because of the lower light absorption.