Etching a laser-cut semiconductor before dicing a die attach film (DAF) or other material layer

摘要

Semiconductor die break strength and yield are improved with a combination of laser dicing and etching, which are followed by dicing an underlying layer of material, such as die attach film (DAF) or metal. A second laser process or a second etch process may be used for dicing of the underlying layer of material. Performing sidewall etching before cutting the underlying layer of material reduces or prevents debris on the kerf sidewalls during the sidewall etching process. A thin wafer dicing laser system may include either a single laser process head solution or a dual laser process head solution to meet throughput requirements.

主权项

1. A laser processing system for dicing a semiconductor wafer including a top surface and a bottom surface, the bottom surface attached to an underlying layer of material, the system comprising:
a first laser processing head for generating a first laser beam, and for providing relative movement of the first laser beam with respect to the top surface of the semiconductor wafer to at least partially dice the semiconductor wafer from the top surface along one or more dicing streets, the first laser beam forming a kerf defined by sidewalls in the semiconductor wafer; a first etch station for etching the sidewalls of the at least partially diced semiconductor wafer to reduce or remove a heat affected zone (HAZ) produced in the sidewalls by the first laser beam; and a dicing station for cutting through the underlying layer of material along the one or more dicing streets so as to separate a die from the semiconductor wafer having at least a predetermined die break strength and to produce a yield of operational die that equals at least a predetermined minimum yield, wherein the first etch station performs the sidewall etching before the dicing station cuts through the underlying layer of material to reduce or prevent debris on the sidewalls from the underlying layer of material during the etching of the sidewalls.