Method for using fuse structure in semiconductor device
AssigneeRohm Co., Ltd.
InventorsHirofumi Nakajima, Takanori Hitomi
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Abstract
This invention provides a semiconductor device wherein a fuse structure can be formed of a normal metal wiring material and the fuse structure can be cut easily and surely. A laser beam is applied three times to the fuse structure composed of an Al wiring 22 and a passivation film 24 to cut the fuse. The Al wiring 22 is sublimated to be almost cut as a consequence of a first laser beam application. However, a part of sublimated aluminum is cooled and solidified to possibly hinder the cutting of the fuse. In order to cope with the above phenomenon, second and third laser beam applications are effected on a point of coordinates P2 (P3) so that the area S2 (S3) is completely damaged.
Claims15
A method for cutting a fuse element using energy from a laser beam, said fuse element being part of fuse structure in a semiconductor device having a substrate, a metal wire forming the fuse element and having a portion to be cut formed above the substrate, and a passivation film covering the metal wire, said metal wire having a center, the method comprising the steps of:
- a first application step for applying the laser beam to the portion of the metal wire to be cut at the center of the metal wire, the portion to be cut of the metal wire on receiving the energy of the laser beam at the center of the metal wire sublimating and expanding under the covering of said passivation film until said portion to be cut of said metal wire together with a covering portion of said passivation film bursts to leave a cut portion and residual metal;
- and
- a second application step for applying the laser beam to the cut portion at a first side of the center to remove the residual metal located at the first side as produced in the first application step.
Dependencies are inferred from the claim text.