JPH09246208A - Semiconductor integrated circuit device and manufacture of the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a semiconductor integrated circuit device having the contact area of high performance and high reliability and to provide the manufacture technology. SOLUTION: Barrier films 12 containing the silicon of contact electrodes are formed on the surface of semiconductor areas 6 whose surfaces are exposed by contact holes 10 in an insulating film 8. Silicon rich films formed on the outer layers of the barrier films 12 and damage areas formed in the semiconductor areas 6 whose surfaces are exposed by the other contact holes 11 are changed into silicon oxide films with an oxide processing. The silicon oxide films are removed and the contact electrodes 17 are formed.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a semiconductor integrated circuit device and its manufacturing technology.

[0002]

2. Description of the Related Art In recent years, LSI (Large Scale Integrated)
2. Description of the Related Art Semiconductor integrated circuit devices such as circuits) have been highly integrated, finely processed, and have high performance, and accordingly, fine semiconductor elements and their wiring structures have been required.

By the way, the present inventor has examined a semiconductor integrated circuit device. The following is a technique studied by the present inventors, and the outline is as follows.

That is, recent semiconductor integrated circuit devices are
After forming a semiconductor region to be a gate electrode and a source / drain in a MOSFET on a semiconductor substrate such as single crystal silicon, and forming an insulating film such as a silicon oxide film on the semiconductor substrate so as to cover the MOSFET,
A contact hole reaching the semiconductor region for the gate electrode and the source / drain is formed in the insulating film by using the photolithography technique and the selective etching technique.

In this case, in the step of forming a contact hole in the insulating film, various impacts are applied to the semiconductor region below the contact hole to form a damaged region, so that the contact hole is formed. After removing the photoresist film as the etching mask by an asher process using oxygen gas, CF ₄ or C is used to remove the damaged area.
A low damage asher process using a fluorine-based gas such as HF ₃ and oxygen gas is performed.

[0006] Note that literatures describing the asher treatment of the photoresist film include, for example, 1989
Some of them are described in "'90 latest semiconductor process technology" p207 to p211 issued by Press Journal Co., Ltd. on January 2nd.

[0007]

However, in the above-described semiconductor integrated circuit device, CF is used to remove a damaged region in the semiconductor region below the contact hole.
_When low damage asher processing using a fluorine-based gas such as ₄ or CHF ₃ and oxygen gas is performed, the contact resistance of the tungsten silicide film as the barrier film of the contact electrode whose surface is exposed by the contact holes in other regions. The present inventor has found that there is a problem that the value becomes high and the electrical characteristics of the semiconductor integrated circuit device are deteriorated.

That is, in the above-described semiconductor integrated circuit device, the surface layer of the tungsten silicide film whose surface is exposed by the contact hole is subjected to the low damage asher process using the fluorine gas such as CF ₄ or CHF ₃ and the oxygen gas. A large amount of silicon is deposited in the area, and the amount of tungsten in the tungsten silicide film in that area is reduced, so that a silicon-rich film is formed in that area and the contact resistance value in that area increases. There is a problem.

An object of the present invention is to provide a semiconductor integrated circuit device having a high-performance and highly reliable contact region and a manufacturing technique thereof.

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

[0011]

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.

That is, the method for manufacturing a semiconductor integrated circuit device according to the present invention is applied to the surface of a semiconductor region whose surface is exposed by a contact hole in an active region of a substrate such as a semiconductor substrate on which a semiconductor element such as MOSFET is formed. The step of forming a barrier film containing silicon of the contact electrode and the silicon rich film formed in the surface layer portion of the barrier film and the contact hole in the other active region are formed in the semiconductor region whose surface is exposed. The method includes an oxidation process of changing the damaged region into a silicon oxide film by an oxidation process, and a process of forming a contact electrode after removing the silicon oxide film.

[0013]

Embodiments of the present invention will be described below in detail with reference to the drawings. In all the drawings for describing the embodiments, components having the same function are denoted by the same reference numerals, and redundant description will be omitted.

1 to 7 are schematic cross-sectional views showing a manufacturing process of a semiconductor integrated circuit device according to an embodiment of the present invention. The semiconductor integrated circuit device of the present invention and its specific manufacturing technique will be described with reference to FIG.

First, as shown in FIG. 1, a selective region on the surface of a p-type semiconductor substrate 1 made of, for example, single crystal silicon is thermally oxidized to LOCOS (Local Oxidation of Silic).
A silicon oxide film having an on structure is formed, and a field insulating film 2 for element isolation is formed between each active region where a semiconductor element is formed.

Next, as shown in FIG. 2, a gate insulating film 3 made of, for example, a silicon oxide film is formed on the surface of the semiconductor substrate 1, and then CVD (Chemical) is performed on the semiconductor substrate 1.
A gate electrode 4 made of a polycrystalline silicon film containing conductive impurities is formed by a vapor deposition method, and an insulating film 5 made of a silicon oxide film is formed on the gate electrode 4.
To form

Next, an n-type impurity is ion-implanted into a region where the surface of the semiconductor substrate 1 is exposed and diffused to form a MOSF.
N-type semiconductor region 6 serving as source and drain of ET
To form

Next, a sidewall insulating film 7 made of, for example, a silicon oxide film is formed on the sidewall of the gate electrode 4.

Since the manufacturing process of this embodiment described above can be performed by diverting the prior art, various modes can be adopted.

Specifically, the semiconductor substrate 1 is used as the starting material in the manufacturing process of the above-described embodiment, but as another aspect, an SOI (Silicon on Insulator) structure which is a substrate different from the semiconductor substrate 1 is used. The substrate of can be used. This SOI structure substrate is configured by forming a silicon single crystal thin film on an insulating region.

The semiconductor region 6 serving as the source and drain of the MOSFET may be LDD (Li
ghly Doped Drain Structure) structure.

Next, as shown in FIG. 3, PSG (Phospho Silicate Glass), which is a silicon oxide film that can be formed by, for example, a CVD method, or a silicon oxide film containing phosphorus.
Film or BPSG (Boro Phospho Silicate Glass) film which is a silicon oxide film containing boron and phosphorus, or SOG (Spin On Glas) which can be formed by a spin coating method.
s) After forming the film, the surface is polished and the surface is planarized if necessary, so that the insulating film 8 is formed on the semiconductor substrate 1.

The flattening treatment can be carried out by flattening the surface of the insulating film 8 by, for example, an etch back method or a chemical mechanical polishing (CMP) method.

The flattening process can be performed by reflowing the PSG film or the BPSG film containing a high concentration of phosphorus at a high temperature.

Next, a photoresist film 9 is formed on the insulating film 8.
Then, the contact hole 10 and the contact hole 11 are simultaneously formed in the selective region of the insulating film 8 by using the photolithography technique and the selective etching technique.

In this case, as the selective etching technique, low pressure dry etching is performed, and then high pressure dry etching is performed, whereby the contact holes 10 and 1 are formed.
1 can be finely processed and damage to the semiconductor region 6 below the contact holes 10 and 11 can be reduced.

That is, in dry etching, if the pressure is low, damage to the base increases, but the processing stability is good and fine processing is possible. Further, in the dry etching, if the pressure is high, the damage to the base is reduced, but the processing stability is lowered and it becomes difficult to perform fine processing. Therefore, by combining the low-pressure dry etching and the high-pressure dry etching, these advantages can be effectively utilized.

Next, as shown in FIG. 4, a barrier film 12 of a contact electrode is formed on the semiconductor region 6 whose surface is exposed by the contact hole 10. The barrier film 12 is made of, for example, a tungsten silicide film. The forming method is as follows, for example. First, after forming a tungsten film on the semiconductor substrate 1, the semiconductor substrate 1
By subjecting the tungsten film to silicon in the semiconductor region 6 by heat treatment or the like, a silicide film is formed in the contact portion between the tungsten film and the semiconductor region 6.
Then, the tungsten film in the non-reactive region is removed.

The barrier film 12 of the contact electrode of the present embodiment uses a barrier film containing silicon and has a high melting point such as a tungsten silicide film, a titanium silicide film or a molybdenum silicide film. By using the metal silicide film, it is possible to reduce the resistance in the semiconductor region 6 in a thin film state and improve the performance of the contact electrode and the semiconductor element.

In particular, since the semiconductor region 6 as the source / drain in the MOSFET has a shallow junction structure formed by fine processing, it tends to have a high resistance. However, by providing the barrier film 12 below the contact electrode, the contact electrode and the MOSFET can be formed. The performance of can be improved.

Also, depending on the design specifications of the semiconductor integrated circuit device, a combination of a semiconductor element that needs to have the barrier film 12 below the contact electrode and a semiconductor element that does not need to have the barrier film 12 below the contact electrode. The structure is effective in achieving high performance and high integration of the semiconductor integrated circuit.

Further, the above-mentioned contact holes 10, 1
In the formation process of No. 1, the contact hole 10 and the contact hole 11 are formed in the same process. However, the insulating film 8 and the barrier film 1 are formed according to the design specifications of the semiconductor integrated circuit device.
After forming the contact hole 10 in the region where 2 is provided,
It is also possible to form the barrier film 12 in that region and then form the contact hole 11 in a region in which it is not necessary to provide the barrier film 12 in the insulating film 8.

In this case, the silicon-rich film 13 containing a large amount of silicon is formed in the surface layer portion of the barrier film 12 containing silicon in the contact hole 10 by the various manufacturing steps described above.

Further, by the various manufacturing steps described above, the damaged region 14 in which the crystal structure of the semiconductor region 6 is damaged is formed in the surface layer portion of the semiconductor region 6 whose surface is exposed by the contact hole 11. To be done.

The silicon-rich film 13 and the damaged region 14 have a large resistance and also cause deterioration of the electrical characteristics of the semiconductor element.

Next, as shown in FIG. 5, the damaged region 14 whose surface is exposed by the silicon rich film 13 and the contact hole 11 in the contact hole 10.
Is oxidized to change the silicon-rich film 13 into a silicon oxide film 15 and damage the damaged region 14
Into a silicon oxide film 16.

The above-mentioned oxidation treatment step can employ various oxidation treatment methods such as thermal oxidation treatment which is widely used, but it is a simple and easy production step and is performed simultaneously with other production steps according to design specifications. It is effective to carry out by the following oxidation treatment method which can be performed.

That is, the oxidation treatment step can be performed by an asher treatment using oxygen gas.

In this case, it is effective to use a plasma asher device to generate a plasma of a reactive gas containing oxygen gas and oxidize silicon by using the plasma to change it into silicon oxide. .

According to the asher treatment using oxygen gas,
Since it is a low damage process and does not give a stimulus that causes a defect to the region such as the semiconductor substrate 1, it can be performed without deteriorating the characteristics thereof.

The silicon-rich film 13 formed in the surface layer of the barrier film 12 containing silicon in the contact hole 10 and the damaged region 14 whose surface is exposed by the contact hole 11 are formed. By being shallow, the oxidation treatment can be performed easily and with a simple manufacturing process.

In the oxidation treatment step, the silicon rich film 13 is formed by using a plasma asher device or the like.
The oxidation treatment of the damaged region 14 can be performed simultaneously with the step of removing the photoresist film.

In this case, the photoresist film as an etching mask when forming various patterns such as an insulating film or a wiring layer by using the photolithography technique and the selective etching technique can be removed, and a thin film of silicon is contained. It is possible to oxidize the region that is being etched and change it into a silicon oxide film.

In addition, as a step of removing the photoresist film as the etching mask, it is divided into a plurality of processes and stepwise performed, and the silicon rich film 13 and the damaged region 14 are oxidized in the last process. Can be

In this case, after performing the ashering process using oxygen gas, the photoresist film can be removed and the damaged region 14 can also be removed.
₄ or CHF ₃ is used to perform a low-damage asher process using a fluorine-based gas and an oxygen gas, and then an asher process is performed using an oxygen gas to utilize the final process of removing the photoresist film. Oxidation treatment can be performed.

[0046] The low damage asher process using a fluorine-based gas and oxygen gas, such as CF ₄ or CHF ₃ can be removed even damage region 14 it is possible to remove the photoresist film, the barrier film 12 Due to the drawback of forming a silicon-rich film on the surface layer, it is effective to divide the step of removing the photoresist film into a plurality of steps and perform this process in the intermediate step.

In addition, the oxidation treatment step can be performed by performing a wafer treatment by a manufacturing apparatus used in another step and then flowing an oxygen gas into the manufacturing apparatus to perform the oxidation treatment using the manufacturing apparatus. .

In this case, a CVD apparatus used when forming an insulating film such as a silicon oxide film by the CVD method or a sputtering apparatus used when forming aluminum or the like as a wiring layer by the sputtering method. It is effective to use a manufacturing apparatus, and after forming an insulating film such as an interlayer insulating film or a wiring layer, an oxygen gas is caused to flow through these manufacturing apparatuses, whereby the silicon-rich film 13 and the damaged region are damaged by a simple manufacturing process. 14 can be formed into a silicon oxide film.

Further, the oxidation treatment step can be performed by the light oxidation treatment in the diffusion step.

In this case, the silicon-rich film 13 formed in the surface layer portion of the barrier film 12 in the contact hole 10 and the damaged region 14 whose surface is exposed by the contact hole 11 are shallow, so that the light oxidation process in the diffusion process is performed. Can be used to perform those oxidation treatments, and as a step of removing the silicon oxide film 15 and the silicon oxide film 16 formed by the oxidation treatment, an etching technique such as wet etching after the light oxidation treatment in the diffusion step is utilized. Therefore, the oxidation process and the subsequent process of removing the silicon oxide film can be performed easily and with a simple manufacturing process.

Next, as shown in FIG. 6, the silicon oxide film 15 whose surface is exposed by the contact hole 10 and the silicon oxide film 16 whose surface is exposed by the contact hole 11 are subjected to various etching such as wet etching. Work to remove by law.

Next, as shown in FIG. 7, after a conductive film made of a conductive material such as aluminum is formed on the semiconductor substrate 1 by a sputtering method or the like, the photolithography technique and the selective etching technique are used. By selectively removing the conductive film, the contact electrode 1
The pattern as No. 7 is formed.

Next, although not shown, a multilayer wiring layer such as an upper wiring layer is formed if necessary, and then a passivation film is formed to complete the manufacturing process of the semiconductor integrated circuit device.

According to the above-described manufacturing technique of the semiconductor integrated circuit device of the present embodiment, the silicon-rich film 13 formed on the surface layer of the barrier film 12 containing silicon as the barrier film of the contact electrode is formed. The damaged region 14 formed in the semiconductor region 6 whose surface is exposed by the contact hole 11 is formed into a silicon oxide film 15 and a silicon oxide film 16 by an oxidation treatment, and after removing them, a contact electrode 17 is formed in the region. By forming the barrier film 1 with the lower part of the contact electrode 17.
2 and the semiconductor region 6 between the silicon-rich film 13
Also, since the damaged region 14 does not exist, the contact resistance is reduced, and a high-performance and highly-reliable contact region can be obtained, and the performance and reliability of the semiconductor integrated circuit device can be improved.

Further, according to the manufacturing technique of the semiconductor integrated circuit device of the present embodiment, the silicon rich film 13 and the damaged region 14 are formed in the silicon oxide film 15 and the silicon oxide film 1.
In the oxidation treatment step of 6 and the subsequent removal step, a step of removing the photoresist film used as an etching mask, a CVD device used when forming an insulating film such as an interlayer insulating film, and a wiring layer are formed. By carrying out using various wafer processing steps such as a sputtering apparatus used at this time or a light oxidation processing step in the diffusion step, it is possible to carry out easily and with simple manufacturing steps.

Although the invention made by the present inventor has been specifically described based on the embodiments of the present invention, the present invention is not limited to the above embodiments, and various modifications are possible without departing from the scope of the invention. It goes without saying that it can be changed.

For example, the semiconductor integrated circuit device of the present invention is
The semiconductor element is not limited to MOSFET, but may be CMOS
By using FET or bipolar transistor or a semiconductor element combining them, MOS type,
It can be applied to a CMOS type or BiCMOS type semiconductor integrated circuit device.

The semiconductor integrated circuit device of the present invention is
It can be applied to various semiconductor integrated circuit devices such as RAM, logic circuits, and microcomputers.

[0059]

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 manufacturing technology of the semiconductor integrated circuit device of the present invention, the surface is formed by the contact layer and the silicon-rich film formed in the surface layer portion of the barrier film containing silicon such as the silicide film as the barrier film of the contact electrode. The contact resistance is small because the damaged region formed in the exposed semiconductor region is converted into a silicon oxide film by oxidation treatment and then the contact electrode is formed in that region after removing the silicon oxide film. Therefore, it is possible to form a contact region having high performance and high reliability, and it is possible to improve the performance and reliability of the semiconductor integrated circuit device.

(2). According to the manufacturing technology of the semiconductor integrated circuit device of the present invention, the step of oxidizing the silicon rich film and the damaged region into the silicon oxide film and the subsequent step of removing the silicon oxide film are performed using the photoresist film used as the etching mask. Various wafer processing steps such as a removal step, a CVD apparatus used for forming an insulating film such as an interlayer insulating film, a sputtering apparatus used for forming a wiring layer, or a light oxidation processing step in a diffusion step. Since it can be performed in a simple manner, it can be performed with a simple manufacturing process.

[Brief description of drawings]

FIG. 1 is a schematic cross-sectional view showing a manufacturing process of a semiconductor integrated circuit device which is an embodiment of the present invention.

FIG. 2 is a schematic sectional view showing a manufacturing process of the semiconductor integrated circuit device according to one embodiment of the present invention;

FIG. 3 is a schematic sectional view showing a manufacturing process of the semiconductor integrated circuit device according to one embodiment of the present invention;

FIG. 4 is a schematic cross-sectional view showing a manufacturing step of the semiconductor integrated circuit device according to one embodiment of the present invention;

FIG. 5 is a schematic cross-sectional view showing a manufacturing step of the semiconductor integrated circuit device according to one embodiment of the present invention;

FIG. 6 is a schematic cross-sectional view showing a manufacturing step of the semiconductor integrated circuit device according to one embodiment of the present invention;

FIG. 7 is a schematic cross-sectional view showing a manufacturing step of the semiconductor integrated circuit device according to one embodiment of the present invention;

[Explanation of symbols]

 1 semiconductor substrate 2 field insulating film 3 gate insulating film 4 gate electrode 5 insulating film 6 semiconductor region 7 sidewall insulating film 8 insulating film 9 photoresist film 10 contact hole 11 contact hole 12 barrier film 13 silicon rich film 14 damage region 15 silicon oxide Film 16 Silicon oxide film 17 Contact electrode

Claims (9)

[Claims] 1. A semiconductor element is formed in a first active region and a second active region in a semiconductor region of a substrate, and silicon under a contact electrode formed in a contact hole in the first active region is formed. The silicon-rich film is removed from the surface layer portion of the barrier film containing Al, and the damaged region is removed from the semiconductor region below the contact electrode formed in the contact hole in the second active region. A semiconductor integrated circuit device characterized in that. 2. The semiconductor integrated circuit device according to claim 1, wherein the barrier film containing silicon is a refractory metal silicide film containing refractory metal and silicon. Semiconductor integrated circuit device. 3. The semiconductor integrated circuit device according to claim 1 or 2, wherein the semiconductor element is a MOSFET. 4. A semiconductor device is formed on a first active region and a second active region of a semiconductor region of a substrate, an insulating film is formed on the substrate, and then a selective region of the insulating film is formed. A step of forming a contact hole; a step of forming a barrier film containing silicon on a surface of a semiconductor region whose surface is exposed by the contact hole in the first active region; The silicon-rich film formed on the surface layer of the barrier film whose surface is exposed by the contact hole and the damaged region formed on the semiconductor region whose surface is exposed by the contact hole in the second active region are oxidized. An oxidation treatment step for changing to a silicon film, and an oxide silicon surface exposed by a contact hole in the first active region. Removing the silicon oxide film whose surface is exposed by the contact hole in the second active region, and the barrier film and the second film exposed by the contact hole in the first active region. And a step of forming a contact electrode on the surface of the semiconductor region whose surface is exposed by the contact hole in the active region. 5. The method of manufacturing a semiconductor integrated circuit device according to claim 4, wherein the silicon-containing barrier film is a refractory metal silicide film made of refractory metal and silicon. Manufacturing method of semiconductor integrated circuit device. 6. The method of manufacturing a semiconductor integrated circuit device according to claim 4, wherein the oxidation treatment step is an asher treatment using oxygen gas. 7. The method of manufacturing a semiconductor integrated circuit device according to claim 4, wherein the oxidation treatment step is performed simultaneously with the step of removing the photoresist film. Device manufacturing method. 8. The method for manufacturing a semiconductor integrated circuit device according to claim 4, wherein in the oxidation process, a wafer is processed by a manufacturing device used by another process. Then, a method for manufacturing a semiconductor integrated circuit device is characterized in that an oxidizing process is performed by using an oxygen gas flowing through the manufacturing apparatus. 9. The method of manufacturing a semiconductor integrated circuit device according to claim 4, wherein the oxidation process is a light oxidation process in a diffusion process.