Diffusion enhanced ion plating for copper fill
US6884329B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Jan 10, 2003 |
| Grant date | Apr 26, 2005 |
| Priority date | — |
| Expiry date | Jan 10, 2023 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH01L21/76877
- WIPO fieldSemiconductors
- WIPO sectorElectrical engineering
Abstract
A method of filling copper into a high-aspect ratio via by a plasma sputter process and allowing the elimination of electrochemical plating. In one aspect of the invention, the sputtering is divided into a first step performed at a low temperature of no more than 100° C. and with at least portions of high wafer bias, thereby filling a lower half of the hole, and a second step performed at a higher temperature, e.g., at least 200° C. and with at least portions of low wafer bias to complete the hole filling. In another aspect of the invention, diffusion promoting gas such as hydrogen is added to the copper sputter plasma. In still another aspect, copper sputtering, even in the final fill phase, is performed through multiple cycles of low-level and high-level pedestal bias to deposit copper on exposed corners and to sputter from the corners.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.