Arrangement and method for providing an imaging path using a silicon-crystal damaging laser
US6709985B1 · kind B1 · utility
Assignee
Inventors
Key dates
| Filing date | Aug 26, 1999 |
| Grant date | Mar 23, 2004 |
| Priority date | — |
| Expiry date | Aug 29, 2020 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH01L2924/15311
- WIPO fieldSemiconductors
- WIPO sectorElectrical engineering
Abstract
According to one aspect of the disclosure, laser-thermal annealing is used to clear an imaging path through the back side of a semiconductor device after the back side of the chip has been thinned to expose a selected region in the substrate. For many applications, thinning results in the formation of crystal defects that inhibit the ability to obtain images through the back side of the semiconductor device. One example embodiment overcomes this problem by thinning via laser-chemical etching the back side of the semiconductor device under a pressure exceeding a threshold level, and then reducing the pressure to a level below the threshold level and scanning the back side of the semiconductor device using a laser at a reduced power level. IR microscopy is then used to capture an image of a circuit in the circuit side of the semiconductor device through the back side of the semiconductor device. One particular example application is directed to a flip-chip semiconductor device. Another aspect of the invention is directed to clearing collision-induced viewing impairments, as may be caused by plasma etching.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.