Photoacoustic control of a pulsed light material removal process
US5194723A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Dec 24, 1991 |
| Grant date | Mar 16, 1993 |
| Priority date | — |
| Expiry date | Dec 24, 2011 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG01N2291/0423
- WIPO fieldMeasurement
- WIPO sectorInstruments
Abstract
The present invention provides an automated system and method for removing one or more layers of a material from a substrate. The system and method include irradiating a structure comprising at least one layer of material formed on a substrate with a light beam having an intensity sufficient to ablate the materials in order to expose selected regions of the substrate, where the ablated material generates photoacoustic signature signals; scanning the structure with the light beam along a predetermined path at a scan speed; detecting the photoacoustic signature signals; determining an updated scan speed functionally related to the detected photoacoustic signals; and directing the scan speed to be equal to the updated scan speed. Another embodiment exposes a selected layer of a multilayered structure in a process which includes irradiating the surface of multilayered structure at a first location with a light beam having sufficient intensity to ablate the irradiated layer and generate photoacoustic pressure wave signals; detecting the photoacoustic pressure wave signals generated at the irradiated surface; comparing representations of the photoacoustic pressure wave signals with a ref…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.