Method for improvement of tungsten chemical-mechanical polishing process
US6287172A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Dec 17, 1999 |
| Grant date | Sep 11, 2001 |
| Priority date | — |
| Expiry date | Dec 17, 2019 |
Classification
- Technology area (CPC B)Performing Operations; Transporting
- CPC primaryB24D13/142
- WIPO fieldMachine tools
- WIPO sectorMechanical engineering
Abstract
A multi-step chemical-mechanical polishing method for improving tungsten chemical-mechanical polishing (CMP) process is provided in the present invention. The method comprises following steps. First, a wafer is placed on a first pad of a CMP system, wherein a head fixes the wafer on the first pad. Then, the head is rotated and the wafer is polished on the first pad by using a tungsten slurry. Next, the wafer is transferred to place on a second pad of the CMP system, wherein the head fixes the wafer on the second pad. Following, the head is rotated and the wafer is polished on the second pad by using the tungsten slurry. Then, the wafer is cleaned on the second pad by using a de-ionic water. Next, the wafer is transferred to place on a third pad of the CMP system, wherein the head fixes the wafer on the third pad. Following, the wafer is cleaned on the third pad by using the de-ionic water. Last, the head is rotated and the wafer is polished on the third pad by using an oxide slurry, wherein a pH value of the tungsten slurry and a pH value of the oxide slurry are opposite.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.