Controlling lateral distribution of air gaps in interconnects
US8110879B2 · kind B2 · utility
Assignees
Inventors
Key dates
| Filing date | Oct 19, 2009 |
| Grant date | Feb 7, 2012 |
| Priority date | — |
| Expiry date | May 14, 2030 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH01L21/7682
- WIPO fieldSemiconductors
- WIPO sectorElectrical engineering
Abstract
Properties of a hard mask liner are used against the diffusion of a removal agent to prevent air cavity formation in specific areas of an interconnect stack. According to one embodiment, there is provided a method in which there is defined a portion on a surface of an IC interconnect stack as being specific to air cavity introduction, with the defined portion being smaller than the surface of the substrate. At least one metal track is produced within the interconnect stack, and there is deposited at least one interconnect layer having a sacrificial material and a permeable material within the interconnect stack. There is defined at least one trench area surrounding the defined portion and forming at least one trench, and a hard mask layer is deposited to coat the trench. At least one air cavity is formed below the defined portion of the surface by using a removal agent for removing the sacrificial material to which the permanent material is resistant.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.