Thermally induced phase switch for laser thermal processing
US6479821B1 · kind B1 · utility
Assignee
Inventors
Key dates
| Filing date | Sep 11, 2000 |
| Grant date | Nov 12, 2002 |
| Priority date | — |
| Expiry date | Sep 11, 2020 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG03G5/16
- WIPO fieldSemiconductors
- WIPO sectorElectrical engineering
Abstract
A method, apparatus and system for controlling the amount of heat transferred to a process region (30) of a workpiece (W) from exposure with a pulse of radiation (10), which may be in the form of a scanning beam (B), using a thermally induced phase switch layer (60). The apparatus of the invention is a film stack (6) having an absorber layer (50) deposited atop the workpiece, such as a silicon wafer. A portion of the absorber layer covers the process region. The absorber layer absorbs radiation and converts the absorbed radiation into heat. The phase switch layer is deposited above or below the absorber layer. The phase switch layer may comprise one or more thin film layers, and may include a thermal insulator layer and a phase transition layer. Because they are in close proximity, the portion of the phase switch layer covering the process region has a temperature that is close to the temperature of the process region. The phase of the phase switch layer changes from a first phase (e.g., solid) to a second phase (e.g., liquid or vapor) at a phase transition temperature (TP). During this phase change, the phase switch layer absorbs heat but does not significantly change temperature.…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.