Structural and Passivative Behaviors of Cu(In) Thin Film

Abstract

This investigation prepares a low-resistivity and self-passivated Cu(In) thin film. The dissociation behaviors of dilute Cu-alloy thin films, containing 1.5-5at.%In, were prepared on glass substrates by a cosputter deposition, and were subsequently annealed in the temperature range of 200-600°C for 10-30 min. Thus, self-passivated Cu thin films in the form In 2 O 3 /Cu/SiO 2 were obtained by annealing Cu(In) alloy films at an elevated temperature. Structural analysis indicated that only strong copper diffraction peaks were detected from the as-deposited film, and an In 2 O 3 phase was formed on the surface of the film by annealing the film at an elevated temperature under oxygen ambient. The formation of In 2 O 3 /Cu/SiO 2 improved the resistivity, adhesion to SiO 2 , and passivative capability of the studied film. A dramatic reduction in the resistivity of the film occurred at 500°C, and was considered to be associated with preferential indium segregation during annealing, yielding a low resistivity below 2.92 lWcm. The results of this study can be potentially exploited in the application of thin-film transistor-liquid crystal display gate electrodes and copper metallization in integrated circuits.

Enhancement of Oxidation Resistance and Electrical Properties of Indium-Doped Copper Thin Films

“…The resistivity of the studied film was less than that of Cu-Cr alloy. 11 Our previous results 10 indicated that the resistivity of the 1.7 at.% In-doped Cu film declined to 2.92 lX cm when the film was annealed at 600°C for 30 min. This value is closer to that of the pure Cu film.…”

“…An earlier study has elucidated the selfpassivation behavior and adhesion to a glass substrate of a low-resistivity Cu(In) thin film. 10 The present study further examines the enhancement of oxidation resistance to support the development of a thin-film transistor and copper interconnection by light doping of a Cu thin film with indium. The results indicated that a 1.9 at.% In-doped Cu thin film retained a low resistivity of 2.83 lX cm.…”

Interficial stability of Cu/Cu(Ru)/Si contact system for barrier-free copper metallization

“…The self-formed thin barrier layers using Cu alloys with various low concentration solutes have been extensively studied by various authors [3][4][5][6][7][8][9][10][11]. The alloying of Cu, however, increases its resistivity by scattering of free electrons, which is the major drawback against using Cu alloys [12][13][14].…”

Property improvement of copper films with zirconium additive for ULSI interconnects

“…The self-formed thin barrier layers using Cu alloys with various low concentration solutes were extensively studied by various authors [6][7][8][9][10][11][12][13]. In addition, it has been reported that copper alloying with a refractory metal such as Ti and Cr can improve the adhesion of copper and alloying with Ti will improve electromigration resistance [14][15][16]. Igarashi and Ito have reported that the electro-migration lifetimes of Cu-Zr alloy films containing a very small amount of Zr after annealing at 500 • C are 10-100 times * Corresponding author.…”