Semiconductor device manufacturing: process – Chemical etching – Vapor phase etching
Patent
1998-03-13
1999-10-19
Powell, William
Semiconductor device manufacturing: process
Chemical etching
Vapor phase etching
216 67, 216 78, 438720, 438742, H01L 2100, B44C 122
Patent
active
059688475
ABSTRACT:
In the preparation of semiconductor structures having multilevel copper conductive features which must be interconnected, it is frequently desired to remove portions of a copper layer deposited over a substrate. In particular, where lines and contacts are created by depositing a copper layer to fill trenches and vias present in a dielectric layer, it is desired to remove the portion of the copper layer which does not form the desired line or contact. The present invention provides a method of etching a copper layer (film) to remove the portion of the film which is not part of the desired conductive interconnect structure, while avoiding over etching of the structure and the formation of corrosive surface contaminants on the surface of the etched copper. The method of etching is referred to as the etchback process, since, in a typical fabrication process, the deposited copper layer is etched back to the upper or "field" surface of a substrate containing trenches and vias which are filled by the copper. The copper layer etchback may be conducted on a substrate surface using a low temperature regime, below about 150.degree. C. Within this low temperature regime, the etchback is preferably conducted using essentially physical bombardment of the copper surface. Or, the etchback may be carried out with the substrate surface at a temperature which falls within a high temperature regime, above about 150.degree. C. Within this high temperature regime, three different etch chemistries may be used. The etch plasma may be formed solely from non-reactive gases; the etch plasma may be formed solely from gases which are produce a reactive species (such as a gas which is a source of chlorine or fluorine), or, the etch plasma may be formed from a combination of non-reactive and reactive gases which are tailored to adjust selectivity and etch rate. When the gas is a source of chlorine or fluorine, it is preferred that the gas be a compound comprising at least one other element in combination with chlorine or fluorine.
REFERENCES:
patent: 4298443 (1981-11-01), Maydan
patent: 5186718 (1993-02-01), Tepman et al.
patent: 5320728 (1994-06-01), Tepman
patent: 5387315 (1995-02-01), Sandhu
patent: 5569627 (1996-10-01), Shinohara et al.
patent: 5578166 (1996-11-01), Hirota
A. Aliouchouche et al., "Laser Chemical etching of copper films", SPIE, vol. 2403, pp. 425-434 (1995).
L. R. Allen et al., "Tungsten plug etchback and substrate damage measured by atomic force microscopy", J. Vac. Sci. Technol. B, vol. 13, No. 3 (May/Jun. 1995).
A. Bertz et al., "Effects of the biasing frequency on RIE of Cu in a Cl.sub.2 -based discharge", Applied Surface Science, 91, pp. 147-151 (1995).
D. Debarre et al., "The role of gas-phase in the laser etching of Cu by Ccl.sub.4 ", Applied Surface Science, 96-98, pp. 453-456 (1996).
T. Gessner et al., "Copper Metallization Technology", pp. 1-23.
B. J. Howard et al, "Reactive ion etching of copper in SiCl.sub.4 -based plasmas", Appl. Phys. Lett., 59(8), pp. 914-916 (Aug. 19. 1991).
Y. Igarishi et al., "High Reliablity Copper Interconnects through Dry Etching Process", Extended Abstracts of the 1994 International Conference on Solid state Devices and Materials, Yokohama, pp. 943-945 (1994),
Y. Igarishi et al., "Thermal Stability of Interconnect of TiN/Cu/TiN Multilayered Structure", Jpn. J. Appl. Phys., vol. 33. pp. 462-465 (1994).
Y. Igarishi et al., "Dry Etching Technique for Subquarter-Micron Copper Interconnects", J. Electrochem. Soc., vol. 142, No. 3, pp. L36-L37 (Mar. 1995).
A. Jain et al., "Thermal dry-etching of copper using hydrogen peroxide and hexafluoracetylacetone", Thin Solid Films, 269, pp. 51-56 (1995).
A. Mak et al., "An Integrated Tungsten Plug Fabrication Process", Conference Proceedings ULSI-VII, Materials Research Society, pp.453-462 (1992).
H. Miyazaki et al., "Copper dry etching using Cl.sub.2 gas as a single reactant and its application to ULSI", Semi Technology Symposium (Japan), Session 5, pp. 41-43 (Dec. 1996).
H. Miyazaki et al., "Copper dry etching with precise wafer-temperature control using Cl.sub.2 gas as a single reactant", J. Vac. Sci. Technol. B 15(2), pp. 237-240 (Mar./Apr. 1997).
K. Ohno et al., "Reactive Ion Etching of Copper Films in a SiCl.sub.4, N.sub.2, Cl.sub.2, and NH.sub.3 Mixture", J. Electrochem. Soc., vol. 143, No. 12 (Dec. 1996).
K. Ohno et al., "Reaction Ion Etching of Copper Films in SiCl.sub.4 and N.sub.2 Mixture", Japanese Journal of Applied Physics, vol. 28, No. 6, pp. L1070-L1072 (Jun. 1989).
Y. Ohshita et al., "Lower temperature plasma etching of Cu using IR light irradiation", Thin Solid Films, 262, pp. 67-72 (1995).
S. M. Rossnagel and J. Hopwood, "Metal ion deposition from ionized magnetron sputtering discharge", J. Vac. Sci. Technol. B,vol. 12, No. 1, pp. 449-453 (Jan./Feb. 1994).
S. M. Rossnagel et al., "Thin, high atomic weight refractory film deposition for diffusion barrier, adhesion layer, and seed layer applications", J. Vac. Sci. Technol. B, vol. 14, No. 3 pp. 1819-1827 (May/ Jun. 1996).
G. C. Schwartz et al., J. Electrochem. Soc., vol. 130, No. 8, pp. 1777-1779 (Aug. 1983).
S. Seo et al., "Characteristics of an Inductively Coupled Cl.sub.2 /Ar Olasma and Its Application to Cu Etching", Electrochemical Society Proceedings, vol. 95-4, pp. 327-338 (1995).
W. Sesselman et al., "The Interaction of Chlorine with Copper. I. Adsorption and surface reaction", Surface Science, 176, pp. 32-66 (1986).
W. Sesselman et al., "The Interaction of Chlorine with Copper. II. Bulk diffusion", Surface Science, 176, pp. 67-90 (1986).
C. Steinbruchel, "Patterning of Copper for Multilevel Metallization: Reactive Ion Etching and Chemical-Mechanical Polishing", Applied Surface Science, 91, pp. 139-146 (1995).
J. Torres, "Advanced Copper Interconnections for Silcon CMOS Technologies", Applied Surface Science, 91, pp. 112-123 (1995).
H. Winters, "Etch products from the reaction on Cl.sub.2 with A1(100) and Cu(100) and XeF.sub.2 with W(111) and Nb", J. Vac. Sci Technol., B3(1), pp. 9-15 (Jan./Feb. 1985).
H. Winters, "The etching of Cu(100) with Cl.sub.2 ", J. Vac. Sci. Technol., A3(3), pp. 786-790 (May/Jun. 1985).
Y. Ye et al., "0.35-Micron and Sub-0.35-Micron Metal Stack Etch in a DPS Chamber--DPS Chamber and Process Characterization", Electrochemical Society Proceedings, vol. 96-12, pp. 222-233 (1996).
U.S. Patent Application, Serial No. 08/869,798 of Ye et al., filed Jun. 5, 1997.
U.S. Patent Application, Serial No. 08/891,410 of Ye et al., filed Jul. 9, 1997.
U.S. Patent Application, Serial No. 08/911,878 of Ye et al., filed Aug. 13, 1997.
Ma Diana Xiaobing
Ye Yan
Applied Materials Inc.
Church Shirley L.
Powell William
LandOfFree
Process for copper etch back does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Process for copper etch back, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Process for copper etch back will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-2055120