Method for laser thermal processing using thermally induced reflectivity switch
US6635588B1 · kind B1 · utility
Assignee
Inventors
Key dates
| Filing date | Feb 19, 2002 |
| Grant date | Oct 21, 2003 |
| Priority date | — |
| Expiry date | Apr 4, 2022 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH01L21/324
- WIPO fieldSemiconductors
- WIPO sectorElectrical engineering
Abstract
Method for controlling heat transferred to a workpiece (W) process region (30) from laser radiation (10) using a thermally induced reflectivity switch layer (60). A film stack (6) is formed having an absorber layer (50) atop the workpiece with a portion covering the process region. The absorber layer absorbs and converts laser radiation into heat. Reflective switch layer (60) is deposited atop the absorber layer. The reflective switch layer comprises one or more layers, e.g. thermal insulator and reflectivity transition layers. The reflective switch layer covering the process region has a temperature related to the temperature of the process region. Reflectivity of the switch layer changes from a low to a high reflectivity state at a critical temperature of the process region, limiting radiation absorbed by the absorber layer by reflecting incident radiation when switched. This limits the amount of heat transferred to the process region from the absorber layer.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.