High speed, laser-based marking method and system for producing machine readable marks on workpieces and semiconductor devices with reduced subsurface damage produced thereby
US7067763B2 · kind B2 · utility
Assignee
Inventor
Key dates
| Filing date | May 15, 2003 |
| Grant date | Jun 27, 2006 |
| Priority date | — |
| Expiry date | Jun 5, 2023 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH01L2924/0002
- WIPO fieldMachine tools
- WIPO sectorMechanical engineering
Abstract
An improved method of laser marking semiconductor wafers is provided wherein undesirable subsurface damage to a silicon semiconductor wafer is avoided while providing a relative improvement in marking speed for a predetermined spot diameter. A laser pulse of a laser beam has a predetermined wavelength, pulse width, repetition rate, and energy. The method further includes irradiating a semiconductor wafer with the pulsed laser beam over a spot diameter to produce a machine readable mark on the semiconductor wafer. The mark has a mark depth. The pulse width is less than about 50 ns, and the step of irradiating irradiates over the spot diameter to produce a mark having a mark depth substantially less than about 10 microns.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.