Abstract
Laser microchemical (LMC) technology has become an important element of the FIA and debug tool set by supplying key steps not well addressed by previous tools. In this paper we report the optimization of the LMC technology to solve key issues for flip chip FIA. Specific processes have been developed for localized thinning of flip chips, in order to enable access of conventional FIA tools. Additional applications include dramatic enhancement of focused ion beam (FIB) rework and 3-D micromachining for prototyping, in-situ trimming, and mastering of microelectromechanical systems (MEMS). Laser etching of silicon is with a high pressure chlorine assist and is l000X the rate of the fastest focused ion beam methods. In contrast to grinding methods, the process introduces no process stress or contamination and retains an average surface roughness of several hundred angstroms. Micronthickness metal lines are laid down in a one-step vapor phase deposition at 200 μm/s writing speed. Rapid deposition combined with the superior quality of the laser interconnect, translates into writing with a conductance per unit writing time of 1000 to 10,000 times the rate of a focused ion beam.
