Laser segmented cutting, multi-step cutting, or both

USRE43605E1 · kind E1 · reissue

Assignee

• ELECTRO SCIENTIFIC INDUSTRIES, INC. · US

Inventors

• James N. O'Brien · Bend, US
• Lian-Cheng Zou · Portland, US
• Yunlong Sun · Beaverton, US
• Kevin P. Fahey · Portland, US
• Michael J. Wolfe · Oldsmar, US
• Brian W. Baird · Portland, US
• Richard Harris · Portland, US

Key dates

• Filing date: Jan 9, 2009
• Grant date: Aug 28, 2012
• Expiry date: Jan 9, 2029

Classification

• Technology area (CPC —): General

Abstract

UV laser cutting throughput through silicon and like materials is improved by dividing a long cut path (112) into short segments (122), from about 10 μm to 1 mm. The laser output (32) is scanned within a first short segment (122) for a predetermined number of passes before being moved to and scanned within a second short segment (122) for a predetermined number of passes. The bite size, segment size (126), and segment overlap (136) can be manipulated to minimize the amount and type of trench backfill. Real-time monitoring is employed to reduce rescanning portions of the cut path 112 (112) where the cut is already completed. Polarization direction of the laser output (32) is also correlated with the cutting direction to further enhance throughput. This technique can be employed to cut a variety of materials with a variety of different lasers and wavelengths. A multi-step process can optimize the laser processes for each individual layer.