Fuse Line Masking for Better Laser Spot Resolution
Original Publication Date: 1985-Nov-01
Included in the Prior Art Database: 2005-Feb-19
For integrated circuits (ICs) which use laser fusing and where tight line pitches make it difficult to implement on-pitch fusing, a fuse masking and framing scheme is featured. Due to laser spot size limitations and accuracy of the laser tool positioning system, a fuse shield material, as shown in the figure, may be used to protect adjacent laser fuse lines from inadvertently being blown where tightly pitched designs are involved. The purpose of the shield material is to reflect and dissipate the laser spot's heat except where it is needed to open the fuse line. A hole in the shield located immediately above each target fuse is provided to increase the amount of laser energy brought to bear on the target directly. The fuse line shield will allow larger than minimum pitch spot sizes to be used without area impact.