Method and system for decoupling inoperative passive elements on a semiconductor chip
US5329237A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Feb 12, 1993 |
| Grant date | Jul 12, 1994 |
| Priority date | — |
| Expiry date | Feb 12, 2013 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH01L2924/3011
- WIPO fieldSemiconductors
- WIPO sectorElectrical engineering
Abstract
The present invention teaches a method and system for disconnecting shorted decoupling capacitors, wherein a semiconductor chip having a plurality of redundant decoupling capacitors. Each of the capacitors is coupled, by means of a link, to a bus having a predetermined voltage. Each link is accessible to light emissions, in planar view. The system comprises a tester for testing the operability of each of the capacitors. In a preferred embodiment, the tester comprises a heating element and a high voltage stress testing element. Under thermal and voltage stress, an infrared signal identifying shorted decoupling capacitors is generated by shorted decoupling capacitors. The system further comprises a sensor for sensing the infrared signal. In one embodiment of the present invention, the sensor comprises an emission microscope for multilevel inspection ("EMMI"). Each inoperable capacitor is decoupled from the bus by disintegrating the link with a laser in response to the infrared signal. In an alternate embodiment, the link is disintegrated by an acid etch comprising H.sub.2 SO.sub.4, H.sub.2 SO.sub.4 and H.sub.2 O.sub.2, or H.sub.2 PO.sub.4.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.