Laser interaction with SiCr thin film resistors: "the bubble theory"

This paper introduces a theoretical model to qualitatively describe the mechanisms involved during laser trimming of SiCr thin film resistors. The model was developed to address the problems encountered when trying to cut these resistors. It is based upon the physical laws of laser-matter interaction and extrapolates them to the confines of a thin film resistor. This was achieved with planar TEM images of the laser cut thin film resistors to provide support for the theory. With this model it was then possible to recommend and implement solutions about the design of the SiCr thin film in order to enhance its capabilities as a potential laser trim tab or thin film fuse.