Active solid-state devices (e.g. – transistors – solid-state diode – Combined with electrical contact or lead – Of specified material other than unalloyed aluminum
Reexamination Certificate
1999-01-08
2001-05-15
Lee, Eddie C. (Department: 2815)
Active solid-state devices (e.g., transistors, solid-state diode
Combined with electrical contact or lead
Of specified material other than unalloyed aluminum
C257S758000, C257S750000, C257S774000
Reexamination Certificate
active
06232664
ABSTRACT:
This application is based on Japanese Patent Application No. 10-148010 filed on May 28, 1998, the entire contents of which are incorporated herein by reference.
BACKGROUND OF THE INVENTION
a) Field of the Invention
The present invention relates to a semiconductor device, and more particularly to a semiconductor device having an Al alloy wiring.
b) Description of the Related Art
A reduction in the resistance and capacitance of a metal wiring, as well as an improvement in its electromigration resistance, are required due to recent demands for a large scale integration and an increase in the operation speed of a semiconductor device. In order to satisfy these requirements, a wiring which includes a lamination of a Ti and/or TiN film and an Al alloy film is employed.
The stronger Al (111) oriented texture of the Al alloy film, the higher electromigration resistance of the Al alloy film (S. Vaidya and A. K. Sinha, Thin Solid Films, 75 (1981) 253-259). The method of laminating the Al alloy film on a refractory metal film, which is made of a Ta—Al alloy, has been proposed as a plan to strengthen the crystallographic orientation of the (111) face of the Al alloy film (H. Toyoda et al., Proceedings of 32nd International Reliability Physics Symposium, 178 (1994)). According to the Toyoda et al. document, when the Al alloy film is formed on the Ta—Al alloy film, the peak height derived as one corresponding to the (111) face from the X-ray diffraction pattern of the Al alloy film is about four times as great as that when the Al alloy film is formed on the TiN/Ti (TiN: the upper film, Ti: the lower film) film.
Now there is a tendency toward a reduction in the thickness of an Al alloy wiring in order to reduce wire capacitance, etc. If the wiring thickness is reduced, the current density in the wiring will increase, which entails the possibility that electromigration occurs. In consideration of this, a wiring structure having a high electromigration resistance is needed.
SUMMARY OF THE INVENTION
It is accordingly an object of the present invention to provide a semiconductor device with an Al alloy wiring having a high electromigration resistance.
According to one aspect of the present invention, there is provided a semiconductor device which comprises a semiconductor substrate, an insulation film formed on the semiconductor substrate, and a wiring formed on a part of the surface area of the insulation film and including a first conductive layer, which is made of Ta in an a phase, and a second conductive layer arranged on the first conductive layer and being made of an Al alloy.
When the second conductive layer, which is made of the Al alloy, is formed on the first conductive layer which is made of Ta in the &agr; phase, the (111) face of the second conductive layer has a strong crystallographic orientation. This ensures a high electromigration resistance to the wiring.
REFERENCES:
patent: 4933743 (1990-06-01), Thomas et al.
patent: 4985750 (1991-01-01), Hoshino
patent: 5221449 (1993-06-01), Colgan et al.
patent: 5281485 (1994-01-01), Colgan et al.
patent: 5313101 (1994-05-01), Harada et al.
patent: 5572072 (1996-11-01), Lee
patent: 5712509 (1998-01-01), Harada et al.
patent: 6028359 (2000-02-01), Merchant et al.
patent: 6054770 (2000-04-01), Toyoda et al.
patent: 6057237 (2000-05-01), Ding et al.
patent: 3-248568 (1991-11-01), None
patent: 4-35035 (1992-02-01), None
patent: 4-318934 (1992-11-01), None
patent: 7-240533 (1995-09-01), None
patent: 8-19516 (1996-02-01), None
patent: WO 92/07968 (1992-05-01), None
S. Vaidya et al.; Thin Solid Films, 75 (1981) pp. 253-259.
H. Toyoda et al.; IEEE/1RPS, 1994, pp. 178-184.
Armstrong Westerman Hattori McLeland & Naughton LLP
Cruz Lourdes
Fujitsu Limited
Lee Eddie C.
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