Microstructure control of Al-Cu films for improved electromigration resistance
- Albuquerque, NM
A process for the forming of Al-Cu conductive thin films with reduced electromigration failures is useful, for example, in the metallization of integrated circuits. An improved formation process includes the heat treatment or annealing of the thin film conductor at a temperature within the range of from 200.degree. C. to 300.degree. C. for a time period between 10 minutes and 24 hours under a reducing atmosphere such as 15% H.sub.2 in N.sub.2 by volume. Al-Cu thin films annealed in the single phase region of a phase diagram, to temperatures between 200.degree. C. and 300.degree. C. have .theta.-phase Al.sub.2 Cu precipitates at the grain boundaries continuously become enriched in copper, due, it is theorized, to the formation of a thin coating of .theta.-phase precipitate at the grain boundary. Electromigration behavior of the aluminum is, thus, improved because the .theta.-phase precipitates with copper hinder aluminum diffusion along the grain boundaries. Electromigration, then, occurs mainly within the aluminum grains, a much slower process.
- Research Organization:
- AT&T
- DOE Contract Number:
- AC04-76DP00789
- Assignee:
- United States of America as represented by United States (Washington, DC)
- Patent Number(s):
- US 5300307
- OSTI ID:
- 869221
- Country of Publication:
- United States
- Language:
- English
Grain Boundary Chemistry in Al-Cu Metallizations as Determined by Analytical Electron Microscopy
|
journal | January 1991 |
High-spatial-resolution x-ray microanalysis of Al-2wt.% Cu aluminum thin films
|
journal | August 1989 |
The evolution of microstructure in Al-2 Pct Cu thin films: Precipitation, dissolution, and reprecipitation
|
journal | September 1990 |
|
conference | December 1991 |
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Related Subjects
control
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improved
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example
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integrated
circuits
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heat
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degree
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24
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grain
boundaries
continuously
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diffusion
occurs
mainly
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time period
integrated circuits
integrated circuit
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phase diagram
film conductor
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phase precipitate
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