Sputtered and anodized capacitors capable of withstanding exposu

Details Sputtered and anodized capacitors capable of withstanding exposu Sputtered and anodized capacitors capable of withstanding exposu

1997-04-09

1999-02-16

Ledynh, Bot L.

Electricity: electrical systems and devices

Electrostatic capacitors

Fixed capacitor

361311, 361313, 361322, 3613215, 427 79, 4274193, H01G 4008, H01G 406, B05D 512

Patent

active

058726969

ABSTRACT:
Novel structures for capacitors which are capable of withstanding heat treatments to at least 400.degree. C. while providing low defect densities and low electrical series resistance in its electrodes are disclosed. In one embodiment of the present invention, a capacitor structure includes a bottom capacitor electrode formed of a first sub-layer of aluminum, a second sub-layer of tantalum nitride, and a third sub-layer of tantalum. The capacitor structure further includes a sputtered dielectric layer of tantalum pentoxide over the tantalum sub-layer of the bottom electrode. The resulting structure is anodized such that the underlying tantalum layer is fully anodized, and preferably such that a portion of the tantalum nitride layer is converted to a tantalum oxy-nitride. The tantalum nitride layer was discovered by the inventors to act as a good high temperature diffusion barrier for the aluminum, preventing the aluminum from migrating into the anodized tantalum pentoxide layer under high temperature processing conditions, where it would chemically reduce the tantalum atoms in the tantalum pentoxide layer and introduce conductive paths of tantalum in the dielectric (tantalum pentoxide) layer. The aluminum layer provides good electrical conductivity for the bottom electrode, and is anodized to fill any pinhole defects in the layers formed above it, thereby increasing manufacturing yields.

REFERENCES:
patent: 3231479 (1966-01-01), Gordon et al.
patent: 3553545 (1971-01-01), Gerstenberg et al.
patent: 3568014 (1971-03-01), Schuermeyer
patent: 3579063 (1971-05-01), Wasa et al.
patent: 3671823 (1972-06-01), Pitetti et al.
patent: 3779689 (1973-12-01), Bodway
patent: 3969197 (1976-07-01), Tolar et al.
patent: 4020222 (1977-04-01), Kausche et al.
patent: 4058445 (1977-11-01), Anders
patent: 4089039 (1978-05-01), Young
patent: 4460938 (1984-07-01), Clei
patent: 4496435 (1985-01-01), Harada et al.
patent: 5005102 (1991-04-01), Larson
patent: 5111355 (1992-05-01), Anand et al.
patent: 5195018 (1993-03-01), Kwon et al.
McLean, D.A. et al., "Tantalum-Film Technology," Proceedings of the IEEE, Dec., 1964, pp. 1450-1462.
Gerstenberg, D., "Properties of Anodic Films Formed on Reactively Sputtered Tantalum," J. Electrochem. Soc., Jun., 1966, pp. 542-547.
Pringle, J.P.S., "Transport Numbers of Metal and Oxygen during the Anodic Oxidation of Tantalum," J. Electrochem. Soc., Mar., 1973, pp. 398-407.
Worobey, et al., "Tantalum Thin-Film RC Circuit Technology for a Universal Active Filter," IEEE Transactions on Parts, Hybrides, and Packaging, vol. PHP-12, No. 4, Dec., 1976, pp. 276-282.
Peters, F.G., et al., "Reverse Bias Life Test Stability of Tantalum-Titanium Anodic Oxide Thin Film Capacitors," J. Electrochem. Soc., vol. 124, No. 6, Jun., 1977, pp. 949-951.
Wittmer, Marc, "High-Temperature Contact Structures for Silicon Semiconductor Devices," Appl. Phys. Lett., vol. 37, No. 6, Sep. 15, 1980, pp. 540-542.
Wittmer, Marc. "Interfacial Reactions Between Aluminum and Transition-metal Nitride and Carbide Films," J. Appl. Phys., vol. 53, No. 2, Feb., 1982, pp. 1007-1012.
Yamada, Keisaku, "Thermodynamical Approach to a New High Dielectric Capacitor Structure: W/HfO.sub.2 W," Extended Abstracts of the 18.sup.th (1986 International) Conference on Solid State Devices and Materials, Tokyo, 1986, pp. 257-260.
Mehrotra et al., "Properties of Direct Current Magnetron Reactivity Sputtered TaN," J. Vac. Sci. Technol., B5(6), Nov./Dec. 1987, pp. 1736-1740.
Byeon, S.G. et al., "High Performance Sputtered/Anodized Tantalum Oxice Capacitors," IEEE, IEDM 88, pp. 722-725, 1988.
Dobashi, T., "Influence of the Ta Migration on Dielectric Properties of Anodized Al-Ta(N)-Al Trilayered Oxide Films," Electronics and Communications in Japan, Part 2, vol. 72, No. 9, 1989, pp. 21-28.
Farooq, M.A. et al., "Tantalum Nitride as a Diffusion Barrier Between Pd.sub.2 Si CoSi.sub.2 and Aluminum," J. Appl. Phys., vol. 65, No. 8, Apr. 15, 1989, pp. 3017-3022.
Matsuhashi et al., "Optimum Electrode Materials for Ta.sub.2 O.sub.5 Capacitors at High and Low Temperature Processes," Extended Abstracts of the 1993 International Conference on Solid State Devices and Materials, 1993, pp. 853-855.
Kambe et al., "MCM Substrate with High Capacitance," MCM '94 Proceedings, pp. 136-141, 1994.
Sun et al., "A Novel Approach for Leakage Current Reduction of LPCVD Ta.sub.2 O.sub.5 Films by Rapid Thermal N.sub.2 O Annealing," IEEE, IEDM 94, 1994, pp. 333-336.
Paik et al., "Thin Film Integral Capacitor Fabricated on a Polymer Dielectric for High Density Interconnect (HDI) Applications," Mat. Res. Soc. Symp. Proc., vol. 390, 1995, pp. 33-38.

Affiliated with

Also associated with

Rating

Sputtered and anodized capacitors capable of withstanding exposu does not yet have a rating. At this time, there are no reviews or comments for this patent.

If you have personal experience with Sputtered and anodized capacitors capable of withstanding exposu, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Sputtered and anodized capacitors capable of withstanding exposu will most certainly appreciate the feedback.

Rate now

Comments { 0 }

Profile ID: LFUS-PAI-O-2067663