Title :
Electroless Co(W,P) and Co(Mo,P) deposition for Cu metallization applications
Author :
Shacham-Diamand, Y. ; Zylberman, A. ; Petrov, N. ; Sverdlov, Y.
Author_Institution :
Dept. of Phys. Electron., Tel-Aviv Univ., Ramat-Aviv, Israel
Abstract :
The barrier properties against Cu diffusion of thin-film (< 30 nm) Co(P) alloys are significantly improved when tungsten is added. It is not known whether the barrier properties are due to tungsten or any other refractory metal will have a similar effect. In this work we present a novel electroless cobalt-molybdenum-phosphorous Co(Mo,P) process. Both Co(W,P) and Co(Mo,P) deposition solutions were studied and we present their characteristics such as deposition rate and solid composition. We also present the thin film resistivity and show that the Mo alloy resistivity is higher than that of the W alloy. Auger electron Spectroscopy (AES) and X-ray Photon Spectroscopy (XPS) determined the film composition. The corrosion resistance of Co alloy/Cu/Co-alloy structures were studied by measuring the thin film resistance versus time at elevated temperatures, up to 350°C. We conclude that both W and Mo alloy have similar barrier and corrosion protection priorities. Therefore, the improved barrier properties, as compared to Co(P) alloy is due the refractory metal and not specific to W
Keywords :
Auger electron spectra; ULSI; X-ray photoelectron spectra; cobalt alloys; copper; corrosion protective coatings; corrosion resistance; diffusion barriers; electrical resistivity; electroless deposited coatings; electroless deposition; integrated circuit metallisation; molybdenum alloys; phosphorus alloys; tungsten alloys; 30 nm; 350 C; AES; Auger electron spectroscopy; Co alloy/Cu/Co alloy structures; CoMoP deposition solution; CoMoP-Cu; CoWP deposition solution; CoWP-Cu; Cu diffusion; Cu metallization applications; X-ray photon spectroscopy; XPS; barrier properties; corrosion resistance; deposition rate; electroless CoMoP process; refractory metal; solid composition; thin film resistivity; thin-film Co alloys; Cobalt alloys; Conductivity; Copper alloys; Corrosion; Electrons; Metallization; Solids; Spectroscopy; Transistors; Tungsten;
Conference_Titel :
Solid-State and Integrated-Circuit Technology, 2001. Proceedings. 6th International Conference on
Conference_Location :
Shanghai
Print_ISBN :
0-7803-6520-8
DOI :
10.1109/ICSICT.2001.981506
