Appeal No. 1996-2088
Application No. 08/082,432
22. A metallization method comprising the steps of:
forming at least one contact hole in an insulating film on a substrate;
forming a barrier metal layer structure on at least a bottom and sidewall of the
hole by depositing a first titantium layer on the sidewall and bottom, forming a titanium
oxynitride layer on the first titanium layer and then depositing a second titanium layer on
the titanium oxynitride layer; and then
depositing an aluminum-based material directly on the second titanium layer in
the contact hole.
The examiner relies upon the following references as evidence of obviousness:
Tracy et al. (Tracy) 4,970,176 Nov. 13, 1990
Sugano et al. (Sugano) 5,290,731 Mar. 01, 1994
(filed Mar. 09, 1992)
Madokoro 3 1-160036 Jun. 22, 1989
(Kokai)
Hu et al. (Hu), “Dry etching of TiN/Al(Cu)/Si for very large scale integrated local
interconnections,” 8 Journal of Vacuum Science and Technology A, 3, 1498-1502 (May/June
1990).
Maeda et al. (Maeda), “Effects of Ti Interlevel Existence in Al/Ti/TiN/Ti Structure for Highly
Reliable Interconnection,” 1985 Symposium on VLSI Technology, IEEE CAT. No. 85, CH 2125-3,
50-51 (May 14-16, 1985/Kobe).
In addition to the foregoing prior art references, the examiner has also relied upon the admitted prior
art set forth and described by appellants on pages 1-4 of the specification (hereinafter referred to as
APA) (answer, page 3).
ISSUES
3We refer in our opinion to the translation of Madokoro prepared for the PTO by Fls, Inc., in April 1993, a
copy of which is attached to this decision.
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