Patent · US Expired

System and method of selectively cleaning copper substrate surfaces, in-situ, to remove copper oxides

US5939334A · kind A · utility

78Cited by
10References
9Claims
0Family size

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Key dates

Filing dateMay 22, 1997
Grant dateAug 17, 1999
Priority date
Expiry dateMay 22, 2017

Classification

  • Technology area (CPC H)Electricity
  • CPC primaryH01L21/02068
  • WIPO fieldSemiconductors
  • WIPO sectorElectrical engineering

Abstract

A system and method of selectively etching copper surfaces free of copper oxides in preparation for the deposition of an interconnecting metallic material is provided. The method removes metal oxides with .beta.-diketones, such as Hhfac. The Hhfac is delivered into the system in vapor form, and reacts almost exclusively to copper oxides. The by-products of the cleaning process are likewise volatile for removal from the system with a vacuum pressure. Since the process is easily adaptable to most IC process systems, it can be conducted in an oxygen-free environment, without the removal of the IC from the process chamber. The in-situ cleaning process permits a minimum amount of copper oxide to reform before the deposition of the overlying interconnection metal. In this manner, a highly conductive electrical interconnection between the copper surface and the interconnecting metal material is formed. An IC having a metal interconnection, in which the underlying copper layer is cleaned of copper oxides, in-situ with Hhfac vapor, is also provided.

Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.