Combination grinding after laser (GAL) and laser on-off function to increase die strength

US9812361B2 · kind B2 · utility

Assignee

• NXP B.V. · NL

Inventors

• Hartmut Buenning · Norderstedt, DE
• Sascha Moeller · Hamburg, DE
• Guido Albermann · Hamburg, DE
• Martin Lapke · Hamburg, DE
• Thomas Rohleder · Hamburg, DE

Key dates

• Filing date: Mar 11, 2014
• Grant date: Nov 7, 2017
• Expiry date: Mar 11, 2034

Classification

• Technology area (CPC H): Electricity
• CPC primary: H01L2221/6834
• WIPO field: Semiconductors
• WIPO sector: Electrical engineering

Abstract

Consistent with an example embodiment, there is a method for preparing integrated circuit (IC) device die from a wafer substrate having a front-side with active devices and a back-side. The method comprises pre-grinding the backside of a wafer substrate to a thickness. The front-side of the wafer is mounted onto a protective foil. A laser is applied to the backside of the wafer, at first focus depth to define a secondary modification zone in saw lanes. To the backside of the wafer, a second laser process is applied, at a second focus depth shallower than that of the first focus depth, in the saw lanes to define a main modification zone, the secondary modification defined at a pre-determined location within active device boundaries, the active device boundaries defining an active device area. The backside of the wafer is ground down to a depth so as to remove the main modification zone. The IC device die are separated from one another by stretching the protective foil.