JPH1056060A - Manufacture of semiconductor device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To enable a conductor film to be formed at a low cost and high in throughput in a wiring pattern forming process by the use of damascene or the like. SOLUTION: A wiring insulating film 2 formed on a substrate 1 is formed into a recessed pattern 2a corresponding to a target wiring pattern or a plug through photolithography, a thin close contact layer 3 is formed thereon, a fluidic paste/solution 4 composed of organic solvent 4a and conductor fine particles 4b of copper (Cu) or the like suspended in it is applied onto all the surface of the wiring insulating film 2 (close contact layer 3), and then the substrate 1 is backed or burned under pressure, whereby a dense conductor film 4c is formed to cover the surface of the wiring insulating film 2 and surely fills the recessed pattern 2a. Thereafter, the conductor film 4c is removed flat through a CMP method or the like so as to make the surface of the wiring insulating film 2 exposed, whereby the conductor pattern 4d is selectively left inside the recessed pattern 2a to function as a wiring pattern or a plug or the like.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a technology for manufacturing a semiconductor device, and more particularly to a technology effective when applied to a process of forming a wiring pattern or a plug by a damascene method or the like.

[0002]

2. Description of the Related Art For example, Industrial Research Co., Ltd., 1996
Published on May 1, 1996, Electronic Materials, May 1996, p. 22
To P27, etc., as one of the processes for forming a metal wiring pattern, a damascene (da
mascene) method is known. That is, a metal thin film is formed on the entire surface of the underlying insulating film on which the groove or hole pattern is formed in advance according to the shape of the target wiring pattern or plug, and the metal film is embedded in the groove or hole pattern. , CMP (Chemical Mechanical Polishing)
: Chemical mechanical polishing) or the like, the metal film covering the base insulating film is removed flat to expose the surface of the base insulating film, and a metal film is selected inside the groove or hole pattern. Thus, a metal wiring pattern or a plug having a desired shape is obtained so that the metal wiring pattern and the plug remain.

In the conventional damascene method, a sputter / reflow method or a CVD method has been used as a method for embedding a metal film in a groove in a base insulating film.

[0004]

However, in the case of the current sputtering / reflow method, the embedding characteristics are relatively poor, and in the case of the CVD method, the deposition rate is low and it is difficult to increase the throughput. Issues.
Further, equipment such as a sputtering apparatus and a CVD apparatus for realizing the above-mentioned sputtering / reflow method or CVD method are both expensive. In particular, in the case where copper or the like having a lower electric resistance value is used as the material of the wiring pattern instead of the current aluminum or the like, these technical problems become more remarkable.

An object of the present invention is to provide a semiconductor device manufacturing technique capable of shortening the time required for a manufacturing process involving formation of a conductive film and improving the throughput.

Another object of the present invention is to provide a semiconductor device manufacturing technique capable of reliably embedding a conductor into a concave pattern formed in an insulating film.

[0007] Another object of the present invention is to reduce the equipment cost.
An object of the present invention is to provide a semiconductor device manufacturing technique capable of constructing and operating a manufacturing process involving formation of a conductor film.

Another object of the present invention is to provide a semiconductor device manufacturing technique capable of obtaining a highly reliable semiconductor device at a low cost and a high yield.

The above and other objects and novel features of the present invention will become apparent from the description of the present specification and the accompanying drawings.

[0010]

SUMMARY OF THE INVENTION Among the inventions disclosed in the present application, the outline of a representative one will be briefly described.
It is as follows.

According to the method of manufacturing a semiconductor device of the present invention, a paste or solution in which conductive fine particles are suspended in an arbitrary solvent is applied to the surface of an insulating film, and the paste or solution is subjected to heat treatment and pressure treatment. The conductive film is formed by applying and firing at least one of the above.

In a process of forming a conductor pattern by a damascene method or the like, a method of forming / embedding a conductor film in a concave pattern formed on the surface of an insulating film corresponding to a target pattern has been proposed. A paste or solution in which fine particles are suspended is applied to the surface of the insulating film and filled into a concave pattern.
The conductor film is formed by performing at least one of a heat treatment and a pressure treatment and baking.

[0013]

Embodiments of the present invention will be described below in detail with reference to the drawings.

FIGS. 1A to 1D are schematic sectional views illustrating an example of a method of manufacturing a semiconductor device according to an embodiment of the present invention in the order of steps.

In the present embodiment, as an example, a case where the present invention is applied to a process of forming a wiring pattern, a conductor plug, and the like by a damascene method in a manufacturing process of a semiconductor device will be described.

First, a wiring insulating film 2 made of, for example, silicon oxide or the like is formed on a substrate 1 such as a semiconductor wafer by, for example, a P-CVD method or the like. By a lithography process and a dry etching process, a concave pattern 2a including a groove, a hole, and the like is formed in a portion where a wiring structure such as a wiring pattern and a plug is to be formed in the wiring insulating film 2 in the future.

Next, on the wiring insulating film 2 on which the concave pattern 2a is formed, as an adhesion layer 3 for realizing good bonding with a conductor film constituting a wiring structure to be produced in the future, for example, T
An iN film is formed extremely thin using a P-CVD method or the like (FIG. 1A).

Further, for example, a fluid paste / solution 4 in which conductive fine particles 4b such as copper (Cu) are suspended in an organic solvent 4a having a reducing action is applied to the surface of the wiring insulating film 2 (adhesion layer 3). Apply to the whole. The mixing ratio of the conductive fine particles 4b to the organic solvent 4a is, for example, 85 to 90.
(% By weight). At this time, the paste / solution 4
The inside of the concave pattern 2a of the wiring insulating film 2 is reliably filled (FIG. 1B).

Here, the organic solvent 4a having a reducing action in which the conductive fine particles 4b such as metal fine powder are dissolved is used as the conductive fine particles 4b.
In addition to the action of removing oxides present on the surface, the conductive fine particles 4b such as metal fine powder are converted into a paste / solution 4 to facilitate the handling. Paste / solution 4
As a method of coating, a low-cost and simple method such as brush coating, spin coating, and dipping can be used.

The width dimension of the concave pattern 2a is, for example, 0.5.
In the case of about μm, the particle diameter of the conductive fine particles 4b is, for example, 0.
It is set to about 05 μm.

Thereafter, the organic solvent 4a in the paste / solution 4 applied to the wiring insulating film 2 is removed, and the conductive fine particles 4 are removed.
For the purpose of reducing the oxide on the surface of b, assembling the conductive fine particles 4b, and the like, baking is performed, for example, at about 300 ° C. under atmospheric pressure. Heating and baking to about 500 ° C. in a pressurized state, and bonding the conductive fine particles 4b to each other by thermal diffusion or the like, forms a dense conductive film 4c made of copper or the like (FIG. 1C).

Finally, the unnecessary conductive film 4c existing outside the concave pattern 2a is removed by, for example, a CMP method or an etch back until the surface of the wiring insulating film 2 is exposed. Alternatively, a conductor pattern 4d functioning as a conductor plug or the like filled in a contact hole / through hole in a multilayer wiring structure or the like is formed (FIG. 1D).

As described above, in the present embodiment, the conductive fine particles 4b such as copper (Cu) are added to the organic solvent 4a.
Of paste / solution 4 in which is suspended, and baking /
Since the dense conductor film 4c is formed through firing, the conductor film 4c having a desired thickness can be quickly formed in a short time as compared with a method such as a P-CVD method or a sputtering / reflow method. Can be. Further, since the paste / solution 4 can be easily applied to the wiring insulating film 2 by inexpensive equipment such as spin coating, brush coating, immersion, etc., expensive equipment such as a CVD apparatus or a sputtering apparatus is not required, and the conductor film 4c is not required. Can be formed at low cost.

Also, due to the fluidity of the paste / solution 4,
Since the paste / solution 4 is reliably filled in the concave pattern 2a formed on the surface of the wiring insulating film 2, the conductor pattern 4d functioning as a wiring pattern, a plug, or the like.
Can reliably prevent the occurrence of defects such as connection failures due to voids and the like, and improve the yield of semiconductor devices. In particular, for example, in the so-called dual damascene method in which the formation of a wiring pattern and a plug is performed at once, the embedding depth in the plug portion is further increased by the sum of the thickness of the wiring pattern and the depth of the plug. Although it becomes difficult to completely embed the conductor by the ordinary CVD method or the sputtering / reflow method, in the case of the present embodiment, since the fluid paste / solution 4 is applied, regardless of the depth, The conductor pattern 4d can be reliably embedded, and the reliability of the obtained wiring structure is further improved.

Therefore, in a damascene process or the like that requires the formation of the conductive film 4c in the concave pattern 2a formed in advance in the wiring insulating film 2, the throughput is improved by shortening the time required for forming the conductive film 4c. Process costs can be reduced by using low-cost equipment.

When copper is used as the material of the wiring pattern, the electric resistance value is lower than that of aluminum or the like, and the migration resistance is higher than that of aluminum. By using copper as in this embodiment, a semiconductor device which operates at high speed and has high reliability can be manufactured.

Although the invention made by the present inventor has been specifically described based on the embodiments, the present invention is not limited to the above embodiments and can be variously modified without departing from the gist thereof. Needless to say, there is.

For example, the conductive fine particles are not limited to copper fine powder and the like, and general conductive fine powder can be used. The solvent is not limited to an organic solvent, and a general solvent capable of suspending the conductor fine powder can be widely used.

[0029]

Advantageous effects obtained by typical ones of the inventions disclosed in the present application will be briefly described.
It is as follows.

(1) According to the method of manufacturing a semiconductor device of the present invention, there is an effect that the time required for the manufacturing process involving the formation of the conductive film can be shortened and the throughput can be improved.

(2) The effect that the conductor can be reliably embedded in the concave pattern formed in the insulating film can be obtained.

(3) It is possible to construct and operate a manufacturing process involving formation of a conductor film at a low equipment cost.

(4) It is possible to obtain a semiconductor device with low cost, high yield, and high reliability.

[Brief description of the drawings]

FIGS. 1A to 1D are schematic cross-sectional views illustrating an example of a method for manufacturing a semiconductor device according to an embodiment of the present invention in the order of steps;

[Explanation of symbols]

 Reference Signs List 1 substrate 2 wiring insulating film 2a concave pattern 3 adhesion layer 4 paste / solution 4a organic solvent 4b conductive fine particles 4c conductive film 4d conductive pattern

Claims (6)

[Claims] 1. A paste or solution in which conductive fine particles are suspended in an arbitrary solvent is applied to the surface of an insulating film, and the paste or solution is subjected to at least one of a heat treatment and a pressure treatment to form a conductor. A method for manufacturing a semiconductor device, comprising forming a film. 2. A first step of forming a concave pattern on the surface of the insulating film, and applying a paste or a solution in which conductive fine particles are suspended in an arbitrary solvent to the surface of the insulating film to form an inner surface of the concave pattern. A second step of filling the paste or solution applied to the insulating film with a pressure treatment and / or a heat treatment to form a third conductive film from the paste or solution. Removing the conductive film until the surface of the insulating film is exposed,
A fourth step of selectively leaving the conductive film inside the concave pattern. 3. The method for manufacturing a semiconductor device according to claim 2, wherein, in the fourth step, the conductive film other than the inside of the concave pattern is flatly removed by a chemical mechanical polishing process (CMP). A method for manufacturing a semiconductor device, comprising: 4. The method of manufacturing a semiconductor device according to claim 2, wherein in the third step, after performing a bake at a predetermined first temperature under an atmospheric pressure, the second step is performed under a pressurized state. A method for manufacturing a semiconductor device, comprising performing a heating process at a temperature. 5. The method according to claim 2, wherein the first temperature is about 300 ° C., and the second temperature is about 300 ° C.
The temperature of the semiconductor device is about 500 ° C. 6. The method of manufacturing a semiconductor device according to claim 2, wherein said conductive fine particles are made of copper (Cu), and said solvent is made of an organic solvent.