CVD and Characterization of Al-Cu Metallization Thin Films

Autor: S. M. Crochiere, Raj Rai, J. M. Tartaglia, D. L. Farrington, H. Maxwell, V. H. Houlding
Rok vydání: 1992
Předmět:
Zdroj: MRS Proceedings. 260
ISSN: 1946-4274
0272-9172
DOI: 10.1557/proc-260-119
Popis: The chemical vapor deposition of Al-Cu thin films on Si, SiO2, and TiN substrates was examined in a vertical low pressure cold wall reactor using trimethylamine alane (TMAA1) at 20 C as the Al source. The Cu sources bis-(hexafluoroacetylacetonato)copper(H)(CuHFA), (cyclopentadienyl)copper(I) triethylphosphine (CpCuPEt3), and (hexafluoroacetylacetonato)copper(I) trimethylphosphine (HfaCuPMe3), were compared. The Cu content of the films was controlled up to“5 wt% by simply varying the temperature of the Cu source. Codeposited Al-Cu films with excellent conductivity, purity, and adhesion properties were obtained with all Cu sources. Optimal film smoothness was achieved at∼350 C. The compounds differed in the ease of control over the %Cu in the films. CuHFA exhibited a massive parasitic reaction which made control very difficult. The Cu(I) complexes showed very minor parasitic reactions. Analysis of films with high Cu content by SEM-EDS showed clear segregation of Cu and Al, consistent with the low solubility of Cu in Al. Films with >2% Cu appeared homogeneous on a μm scale by both SEM-EDS and SIMS depth profiling. TEM of film cross sections revealed a polycrystalline Al film with small (20–100 Å) Cu-rich particles dispersed throughout the Al grains. These particles exhibited bright field-dark field contrast characteristic of crystalline material.
Databáze: OpenAIRE
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