Methods and structures for metal interconnections in integrated circuits
US6121126A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Feb 25, 1998 |
| Grant date | Sep 19, 2000 |
| Priority date | — |
| Expiry date | Feb 25, 2018 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY10S438/933
- WIPO fieldSemiconductors
- WIPO sectorElectrical engineering
Abstract
A typical integrated-circuit fabrication requires interconnecting millions of microscopic transistors and resistors with metal wires. Making the metal wires flush, or coplanar, with underlying insulation requires digging trenches in the insulation, and then filling the trenches with metal to form the wires. Trench digging is time consuming and costly. Accordingly, the invention provides a new "trench-less" or "self-planarizing" method of making coplanar metal wires. Specifically, one embodiment forms a first layer that includes silicon and germanium; oxidizes a region of the first layer to define an oxidized region and a non-oxidized region; and reacts aluminum or an aluminum alloy with the non-oxidized region. The reaction substitutes, or replaces, the non-oxidized region with aluminum to form a metallic wire coplanar with the first layer. Another step removes germanium oxide from the oxidized region to form a porous insulation having a very low dielectric constant, thereby reducing capacitance. Thus, the present invention not only eliminates the timing-consuming, trench-digging step of conventional methods, but also reduces capacitance which, in turn, enables faster, more-efficie…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.