Recovery of hydrophobicity of low-k and ultra low-k organosilicate films used as inter metal dielectrics
US7179758B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | May 25, 2004 |
| Grant date | Feb 20, 2007 |
| Priority date | — |
| Expiry date | May 25, 2024 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH01L2924/0002
- WIPO fieldSemiconductors
- WIPO sectorElectrical engineering
Abstract
Often used to reduce the RC delay in integrated circuits are dielectric films of porous organosilicates which have a silica like backbone with alkyl or aryl groups (to add hydrophobicity to the materials and create free volume) attached directly to the Si atoms in the network. Si—R bonds rarely survive an exposure to plasmas or chemical treatments commonly used in processing; this is especially the case in materials with an open cell pore structure. When Si—R bonds are broken, the materials lose hydrophobicity, due to formation of hydrophilic silanols and low dielectric constant is compromised. A method by which the hydrophobicity of the materials is recovered using a novel class of silylation agents which may have the general formula (R2N)XSiR′Y where X and Y are integers from 1 to 3 and 3 to 1 respectively, and where R and R′ are selected from the group of hydrogen, alkyl, aryl, allyl and a vinyl moiety. Mechanical strength of porous organosilicates is also improved as a result of the silylation treatment.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.