JP2732903B2 - Method for manufacturing electrode wiring of semiconductor integrated circuit device - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to a method for manufacturing an electrode wiring in a semiconductor, particularly, an VLSI.

(Prior art) Conventionally, technologies in such a field include, for example, Showa 63
Spring Proceedings of the Society of Applied Chemistry, 20p-V-14, "Cu Coating Effect on Al Flattening by Excimer Laser Irradiation", P.643, Ryoichi Mukai (2 others).

The conventional Al film formation method has mainly focused on the sputtering method.However, this method extremely reduces the step coverage for VLSI devices whose contact hole steps exceed an aspect ratio of 0.5. There was a problem in point.

As techniques for this, the development of a selective WCVD method (selective tungsten vapor deposition method), an Al bias sputtering method, an Al laser flow method disclosed in the above-mentioned literature, and the like have been advanced.

FIG. 3 is a diagram showing an example of a method for manufacturing an electrode wiring using such a conventional Al laser flow method.

First, as shown in FIG. 3A, a transistor or a capacitor (not shown) is formed on a Si substrate 1 by a conventional LSI manufacturing method, and then a contact hole is formed in an insulating film 2.
By sputtering method, Al-1.5% Si-1% Cu film 3 is 0.1 μm
accumulate. Furthermore, by sputtering, Cu
A film 4 is deposited at 500 °.

The substrate thus obtained is placed in a reaction chamber 10 shown in FIG. 4, and irradiated with a beam from an ArF excimer laser 11. The irradiation conditions are an energy density of 3 to 5 J / cm ² and a repetition frequency of 100 Hz. As a result, most of the laser light is absorbed by the Cu film 4, and its thermal energy is transmitted to the Al film and flows, and a flat Al wiring film 3 'is formed as shown in FIG. 3 (b). . At this time, Cu film 4 which is an anti-reflection film
Is melted and evaporated, but a part (1 wt% or less) is taken into the Al—Si—Cu film. Thereafter, a pattern is formed by RIE (reactive ion etching) using wiring photolithography and BCl ₃ gas.

Next, as shown in FIG. 3C, a plasma SiN film as a passivation film 5 is deposited.

In FIG. 4, 12 is a substrate, 13 is a gas supply system,
14 is a heater, 15 is a temperature controller, and 16 is a turbo exhaust system.

(Problems to be Solved by the Invention) However, according to the above method, although the step coverage is improved, the electromigration resistance in the submicron fine wiring is used because the wiring material of Al-Si-Cu is used. In addition, there is a problem that the resistance to stress migration is insufficient.

SUMMARY OF THE INVENTION It is an object of the present invention to provide a method of manufacturing an electrode wiring of a semiconductor integrated circuit device having high migration resistance by a laser flow method in order to eliminate the problems of step coverage and migration resistance.

(Means for Solving the Problems) In order to achieve the above object, the present invention provides a method for manufacturing an electrode wiring of a semiconductor integrated circuit device, wherein Al-
The substrate completed up to the step of depositing the Si-Cu film is set in a vacuum reaction chamber, a gas containing B and a gas containing Hf are introduced into the reaction chamber, and an excimer laser having a wavelength absorbed by the gas is introduced. The beam is radiated.

(Operation) According to the present invention, as described above, the Al-Si-Cu film deposition step is completed in the vacuum chamber of the Al laser flow device.
The excimer laser beam was irradiated with the Si substrate inserted and the gas containing the element to be added into the Al-Si-Cu film was introduced, so that the electrode wiring was flattened simultaneously with the formation of the Al alloy material. It can be carried out.

(Example) Hereinafter, an example of the present invention will be described in detail with reference to the drawings.

FIG. 1 is a sectional view showing a manufacturing process of an electrode wiring of a semiconductor integrated circuit device according to an embodiment of the present invention, and FIG. 2 is a configuration diagram of a laser flow device used for manufacturing the electrode wiring.

In FIG. 2, reference numeral 20 denotes a vacuum reaction chamber, 21 denotes an ArF excimer laser, 22 denotes a Si substrate, 23 denotes a gas supply system, 24 denotes a heater, 25 denotes a temperature controller, 26 denotes an exhaust system, 27 denotes a bubbler tube, and 28 denotes a gas. It is an introduction pipe.

As shown in FIG. 1 (a), a transistor and a capacitor (not shown) are formed on the Si substrate 31 by the same process as in the prior art.
Is formed, a contact hole is opened in the insulating film 32, and an Al-1.0-3.0% Si-0.2-4.0% Cu film 33 is formed by sputtering.
Deposit 0.1 μm. Further, a Cu film 34 as an anti-reflection film is deposited to a thickness of 500 ° by a sputtering method.

Next, the Si substrate 31 is put into the vacuum reaction chamber 20 of the laser CVD apparatus shown in FIG.

Therefore, after heating the Si substrate 31 to 300 ° C., the gas introduction pipe 2
The liquid HfCl ₄ in the bubbler tube 27 is introduced through 8 with an Ar carrier gas. HfCl ₄ introduction system is bubbler tube 27 and gas introduction tube 28
Is stored in a constant temperature bath, and the inside of the bath is kept at 150 ° C. so that the vapor pressure of HfCl ₄ becomes about 0.1 mmHg.

Here, the reaction pressure by introducing HfCl ₄ is set to 1 Torr.
After setting the Ar gas flow rate, B ₂ H ₆ gas is introduced by the gas supply system 23, and the gas flow rate is set so that the reaction pressure becomes 1.2 Torr.

Next, the energy density was 4 J / cm ² , the pulse width was 55 nsec, the repetition frequency was 100 Hz, and the beam size was 5 × 5 with respect to the Si substrate 31.
Under the condition of mm, a rectangular beam is irradiated vertically from the ArF excimer laser 21. Then, the beam penetrates about 10 mm into the surface of the Al—Si—Cu film 33, and that part is melted. At the same time, B ₂ H ₆ and HfCl molecules adsorbed on the surface of the Cu film 34 are decomposed, and part of boron (B) and hafnium (Hf) is converted to Al—Si—.
It is taken into the Cu film 33. As a result, an Al alloy film 33 'containing 1 wt% or less of B and Hf in addition to Si and Cu added to the sputtered film from the beginning is formed. Of course, this Al alloy film
33 'flows into the contact hole and becomes flat as shown in FIG. 1 (b).

Subsequent steps are the same as in the prior art. After patterning of the Al wiring by photolithography, sintering is performed to deposit a passivation film 35, and the pre-processing of the device is completed as shown in FIG. I do.

The wavelength of the excimer laser beam is a wavelength absorbed by the gas containing boron and the gas containing Hf, that is, 300 nm.
ArF (wavelength 130n)
Not limited to m), KrF (wavelength 254 nm) and XeCl (wavelength 308 nm) may be used.

FIG. 5 shows the electromigration life of the Al—Si—Cu—Hf—B wiring thus configured. Here, the current density is 5 × 10 ⁶ A / cm ² , the sample temperature is 200 ° C., and the wiring width is 1.0 μm.

As shown in this figure, the average electromigration lifetime MTTF of the conventional Al-Si-Cu wiring film is 700 hours, whereas the case of the Al-Si-Cu-Hf-B wiring film of the present invention is 700 hours. This is 3,000 hours, a significant increase, more than four times that of the conventional one.

It should be noted that the present invention is not limited to the above embodiment, and various modifications are possible based on the gist of the present invention.
They are not excluded from the scope of the present invention.

(Effects of the Invention) As described above in detail, according to the present invention, since the Al-Si-Cu-Hf-B film is used as the wiring, the migration life can be greatly improved.

Further, since the Al flow can be flattened by the laser flow, it can be applied to a submicron wiring in a VLSI device having a step with a high aspect ratio.

[Brief description of the drawings]

1 is a sectional view showing a manufacturing process of an electrode wiring of a semiconductor integrated circuit device according to an embodiment of the present invention, FIG. 2 is a configuration diagram of a laser flow device used for manufacturing the electrode wiring, and FIG. FIG. 4 is a cross-sectional view of a manufacturing process of an electrode wiring using a laser flow method, FIG. 4 is a configuration diagram of a conventional laser flow device, and FIG. 20: Vacuum reaction chamber, 21: ArF excimer laser, 2
2,31 ... Si substrate, 23 ... Gas supply system, 24 ... Heater, 25
... temperature controller, 26 ... exhaust system, 27 ... bubbler tube, 28 ... gas introduction tube, 32 ... insulating film, 33 ... Al-1.0
~ 3.0% Si-0.2 ~ 4.0% Cu film, 34 ... Cu film, 35 ... Passivation film.

Claims (2)

(57) [Claims] (A) A substrate completed up to a step of depositing an Al—Si—Cu film as a wiring is set in a vacuum reaction chamber, and (b) a gas containing B and a gas containing Hf are introduced into the reaction chamber. (C) a method of manufacturing an electrode wiring of a semiconductor integrated circuit device, which comprises irradiating an excimer laser beam having a wavelength absorbed by the gas. 2. The method according to claim 1, wherein said excimer laser beam is ArF, KrF or XeCl.