Diffusion Barriers/Adhesion Promoters. Surface and Interfacial Studies of Copper and Copper-Aluminum Alloys Metadata

Title

• Main Title Diffusion Barriers/Adhesion Promoters. Surface and Interfacial Studies of Copper and Copper-Aluminum Alloys

Creator

• Author: Shepherd, Krupanand Solomon
  Creator Type: Personal

Contributor

• Chair: Kelber, Jeffry A.
  Contributor Type: Personal
  Contributor Info: Major Professor
• Committee Member: Acree, William E. (William Eugene)
  Contributor Type: Personal
• Committee Member: Braterman, Paul S.
  Contributor Type: Personal
• Committee Member: Golden, David E.
  Contributor Type: Personal

Publisher

• Name: University of North Texas
  Place of Publication: Denton, Texas

Date

• Creation: 2000-08

Language

• English

Description

• Content Description: The focus of this research is to study the interaction between copper and the diffusion barrier/adhesion promoter. The behavior of copper sputter-deposited onto sputter-cleaned tantalum nitride is investigated. The data show that copper growth on tantalum nitride proceeds with the formation of 3-D islands, indicating poor adhesion characteristics between copper and Ta0.4N. Post-annealing experiments indicate that copper will diffuse into Ta0.4N at 800 K. Although the data suggests that Ta0.4N is effective in preventing copper diffusion, copper's inability to wet Ta0.4N will render this barrier ineffective. The interaction of copper with oxidized tantalum silicon nitride (O/TaSiN) is characterized. The data indicate that initial copper depositions result in the formation a conformal ionic layer followed by Cu(0) formation in subsequent depositions. Post-deposition annealing experiments performed indicate that although diffusion does not occur for temperatures less than 800 K, copper "de-wetting" occurs for temperatures above 500 K. These results indicate that in conditions where the substrate has been oxidized facile de-wetting of copper may occur. The behavior of a sputter-deposited Cu0.6Al0.4 film with SiO2 (Cu0.6Al0.4/SiO2) is investigated. The data indicate that aluminum segregates to the SiO2 interface and becomes oxidized. For copper coverages less than ~ 0.31 ML (based on a Cu/O atomic ratio), only Cu(I) formation is observed. At higher coverages, Cu(0) is observed. These data are in contrast with the observed behavior of copper metal deposited onto SiO2 (Cu/SiO2). The data for Cu/SiO2 show that copper does not wet SiO2 and forms 3-D nuclei. Furthermore, post-annealing experiments performed on Cu0.6Al0.4/SiO2 show that neither de-wetting nor diffusion of copper occurs for temperatures up to 800 K, while Cu diffusion into SiO2 occurs ~ 600 K. These data indicate that aluminum alloyed with copper at the SiO2 interface serves as an effective adhesion promoter and thermal diffusion barrier.

Subject

• Library of Congress Subject Headings: Copper.
• Library of Congress Subject Headings: Copper alloys.
• Library of Congress Subject Headings: Tantalum.
• Library of Congress Subject Headings: Diffusion.
• Library of Congress Subject Headings: Adhesion.
• Keyword: copper
• Keyword: tantalum nitride
• Keyword: adhesion characteristics

Collection

• Name: UNT Theses and Dissertations
  Code: UNTETD

Institution

• Name: UNT Libraries
  Code: UNT

Rights

• Rights Access: public
• Rights License: copyright
• Rights Holder: Shepherd, Krupanand Solomon
• Rights Statement: Copyright is held by the author, unless otherwise noted. All rights reserved.

Resource Type

• Thesis or Dissertation

Format

• Text

Identifier

• OCLC: 47566525
• UNT Catalog No.: b2304437
• Archival Resource Key: ark:/67531/metadc2603

Degree

• Degree Name: Doctor of Philosophy
• Degree Level: Doctoral
• Degree Discipline: Chemistry
• Academic Department: Department of Chemistry
• Degree Grantor: University of North Texas

Note