Advanced electrolytic polish (AEP) assisted metal wafer planarization method and apparatus
US6299741A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Nov 29, 1999 |
| Grant date | Oct 9, 2001 |
| Priority date | — |
| Expiry date | Nov 29, 2019 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH01L21/32115
- WIPO fieldSemiconductors
- WIPO sectorElectrical engineering
Abstract
In advanced electrolytic polish (AEP) method, a metal wafer (10) acts as an anodic electrodes and another metal plate (65) is used as a cathodic electrode. A voltage differential is applied to the anode and cathode under a predetermined anodic dissolution current density. This causes a reaction that provides a planarized surface on the metal wafers. Additives are included in the electrolyte solution (55) which adsorb onto the wafer surface urging a higher removal rate at higher spots and a lower removal rate at lower spots. Also, in another embodiment of the present invention is a pulsed-electrolytic process (260) in which positive and negative potentials are applied to the anodic and cathodic electrodes alternately, further encouraging surface planarization.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.