CMP process using indicator areas to determine endpoint
US5972787A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Aug 18, 1998 |
| Grant date | Oct 26, 1999 |
| Priority date | — |
| Expiry date | Aug 18, 2018 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH01L2924/0002
- WIPO fieldSemiconductors
- WIPO sectorElectrical engineering
Abstract
The method of polishing metal layers on wafers comprises the steps of: providing indicator areas on said wafer, said indicator areas having combinations of line widths and pattern factors violating existing ground rules of metal lines thereby said indicator areas being dished out during said polishing using a chemical-mechanical polisher to polish the metal layers to remove material therefrom, inspecting indicator areas on the wafer to determine an amount of material removed from said areas, and adjusting the operation of the chemical-mechanical polisher in response to the inspection of the indicator areas. The indicator areas may include macroblocks comprised of a multitude of individual blocks. The wafer may be inspected by optically identifying the polishing state of to blocks in the macroblock. Additionally, the process may be automated for mass production. A feedback loop to the polisher can be formed where data from optical inspection of macroblocks on a polished wafer can be immediately fed back to the polisher in order to adjust process parameters.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.