Patent ID: 6972268
Filing Date: 2005-12-06
Classification: B23K,H01L,H05K

Abstract:
1. A method of laser processing a multi-level, multi-material device including a substrate, a microstructure and a multi-layer stack, the stack having at least two inner dielectric layers which separate the microstructure from the substrate, the method comprising: generating a pulsed laser beam having a predetermined wavelength less than an absorption edge of the substrate, the substrate having a relatively high absorption coefficient at the predetermined wavelength and the stack having a low absorption coefficient at the predetermined wavelength and including at least one laser pulse wherein at least reflections of the laser beam by the layers of the stack substantially reduce pulse energy density at the substrate relative to at least one other wavelength and wherein the at least one laser pulse has a duration of greater than a few picoseconds to several nanoseconds; and processing the microstructure with the at least one laser pulse wherein pulse energy density at the microstructure is sufficient to remove the microstructure while avoiding damage to the substrate and the inner layers of the stack.