Elimination of photo-induced electrochemical dissolution in chemical mechanical polishing
US6153043A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Feb 6, 1998 |
| Grant date | Nov 28, 2000 |
| Priority date | — |
| Expiry date | Feb 6, 2018 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH01L21/67028
- WIPO fieldSemiconductors
- WIPO sectorElectrical engineering
Abstract
Eliminating exposure of PN junctions to light capable of invoking a photovoltaic effect and/or inhibiting the oxidation and reduction reactions induced by the photovoltaic effect prevents the electrochemical dissolution of metal components on semiconductor devices by electrolysis. A darkened enclosure for use on tools for wafer CMP, brush cleaning, unloading, and rinsing will eliminate exposure. Alternatively, illumination of a semiconductor wafer can be limited to wavelengths of light that do not provide enough energy to induce a photovoltaic effect. An inhibitor in the CMP slurry and/or post-CMP water rinse blocks the oxidation and/or reduction reactions. A blocking agent, such as a high molecular weight surfactant, will interfere with both the oxidation and reduction reactions at the metal surface. Also, a poisoning agent will impede the reduction portion of electrolysis.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.