Semiconductor device manufacturing: process – Chemical etching – Vapor phase etching
Reexamination Certificate
2006-06-20
2006-06-20
Goudreau, George A. (Department: 1763)
Semiconductor device manufacturing: process
Chemical etching
Vapor phase etching
C216S062000, C216S067000, C216S078000, C438S705000, C438S720000, C438S734000
Reexamination Certificate
active
07064076
ABSTRACT:
The subject invention pertains to a method and apparatus for etching copper (Cu). The subject invention can involve passing a halide gas over an area of Cu such that CuX, or CuX and CuX2, are formed, where X is the halide. Examples of halides which can be utilized with the subject matter include, but are not necessarily limited to, Cl, Br, F, and I. Once the CuX, or CuX and CuX2, are formed the subject invention can then involve passing a reducing gas over the area of Cu for a sufficient time to etch away at least a portion of the CuX, or CuX2, respectively. With respect to a specific embodiment in which CuX and CuX2are produced when the halide gas is passed over the area of Cu, the reducing gas can be passed until essentially all of the CuX2is etched and at least a portion of the CuX is etched. Examples of reducing gases which can be utilized with the subject invention include, but are not necessarily limited to, hydrogen gas and hydrogen gas plasma. The subject invention can accomplish the etching of Cu by passing the reducing gas over the Cu so as to be on a CuX2—Cu3X2metastable line when etching CuX2and to be a CuY—CuX metastable line, where Y is the reducing gas element, when etching CuX. FIGS.5, 6,and8,show such metastable lines for Cu, with X being Cl, from temperatures ranging from 50° C. to 200° C. These can be extrapolated to other temperatures, for other halides, and/or other reducing gases. The subject invention can be used to, for example, etch partial into a layer of Cu, through a layer of Cu, or to smooth a Cu surface.
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Goudreau George A.
Saliwanchik Lloyd & Saliwanchik
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