KR20040001871A - Method for fabricating semiconductor device having metal-gate electrode - Google Patents

Abstract

PURPOSE: A method for manufacturing a semiconductor device is provided to be capable of preventing the oxidation of a gate metal film and the formation of an oxide layer at the interface between the gate metal film and a gate polysilicon layer. CONSTITUTION: A gate oxide layer(32) is formed on a semiconductor substrate(31). A polysilicon layer(33a) is formed on the gate oxide layer. A tungsten silicon nitride layer(34a) is formed on the polysilicon layer. A tungsten film(36a) is formed on the tungsten silicon nitride layer. A gate electrode is then formed by sequentially patterning the tungsten film, the tungsten silicon nitride layer and the polysilicon layer. Then, selective reoxidation processing is performed to the exposed gate oxide layer.

Description

Method for fabricating a semiconductor device having a metal gate electrode {Method for fabricating semiconductor device having metal-gate electrode}

The present invention relates to a method for manufacturing a semiconductor device, and more particularly, to a method for manufacturing a semiconductor device having a metal gate electrode.

Recently, as semiconductor devices have been highly integrated, the widths of impurity regions and gate electrodes used as source and drain regions have decreased. Accordingly, the semiconductor device has a problem in that an operating speed decreases due to an increase in contact resistance of an impurity region and sheet resistance (Rs) of a gate electrode.

Therefore, in the case where the wirings of the elements in the semiconductor element are formed of low-resistance materials such as aluminum alloy and tungsten, or formed of polycrystalline silicon such as the gate electrode, a silicide layer is formed to reduce the resistance.

On the other hand, in the semiconductor device fabrication using the polysilicon film as the gate electrode, since the gate oxide film exposed during the polysilicon film etching is damaged, the side surface of the polysilicon film is selectively oxidized to recover the damaged gate oxide film while maintaining the resistance of the gate electrode. Re-oxidation is involved.

Here, the reoxidation process of the gate oxide film recovers microtrench and loss generated in the gate oxide film during etching of the gate electrode, oxidizes the remaining polysilicon film remaining on the gate oxide film, and at the edge of the gate electrode. In order to improve the reliability by increasing the thickness of the gate oxide film, progress is being made.

In particular, the gate oxide film on the edge of the gate electrode has hot carrier characteristics, sub-threshold voltage characteristics (leakage current, gate induced drain leakage (GIDL)) and punchthrough depending on the thickness and film quality. Characteristics, device operation speed.

Therefore, the gate oxide film at the edge of the gate electrode should be grown to a certain thickness or more, and the oxide film thus grown is called a graded gate oxide film (hereinafter, referred to as a 'GGO film') or a spacer bottom oxide (SBO) film. The reprocessing process must proceed essentially.

Recently, in order to lower the resistance of the gate electrode, a laminated structure of a polysilicon film and a metal film is applied.

1 is a view schematically showing a method for manufacturing a semiconductor device according to the prior art.

Referring to FIG. 1, a gate oxide film 12 is formed on a semiconductor substrate 11, and a polysilicon film 13, a tungsten film 14, and a hard mask 15 are sequentially deposited on the gate oxide film 12. do. Next, after the hard mask 15 is etched first, the tungsten film 14 and the polysilicon film 13 are sequentially etched to form a gate pattern.

When forming the gate pattern described above, a part of the gate oxide film 12 exposed by etching the polysilicon film 13 is damaged.

In order to recover the damage of the gate oxide film 12, a selective reoxidation process is performed in a hydrogen rich (H ₂ rich) atmosphere. In the selective reoxidation process, the gate oxide film 12 is modified to a GGO film 12a having an increased thickness than the initial deposition thickness, and the polysilicon film 13 as the exposed side of the polysilicon film 13 is oxidized. An oxide film 16 is formed on the side of the.

As described above, in the prior art, the stacked gate electrode of the polysilicon film 13 and the tungsten film 14 prevents problems such as rapid volume expansion and increase in surface resistance during subsequent high thermal or oxidation processes. In particular, a selective reoxidation process is applied to prevent the tungsten film from being oxidized in the oxidation atmosphere of the gate reoxidation process.

That is, the hydrogen (H ₂₎ a (H ₂ rich) tungsten film 14 in an oxidizing atmosphere containing a large amount as shown in Figure 1 was without the oxide only the polysilicon film 13, a polysilicon film ( It is a process of forming the oxide film 16 in the side surface of 13).

However, during the selective reoxidation process, the tungsten film, which is a metal film, is not oxidized, but a thin SiO ₂ film 17 is formed at the interface between the polysilicon film and the tungsten film, and the oxide film 17 thus formed greatly degrades the operation characteristics of the semiconductor device. There is a problem. In particular, since the selective reoxidation process is a high temperature oxidation process containing an O ₂ or H ₂ O component, there is a high possibility of forming more reactants such as SiO _{2 at the} interface between the polysilicon film and the tungsten film.

The present invention has been made to solve the above problems of the prior art, an oxide film or a reaction layer is formed at the interface between the metal film and the polysilicon film forming the gate electrode while preventing the oxidation of the metal film forming the gate electrode during the gate reoxidation process It is an object of the present invention to provide a method for manufacturing a semiconductor device which is suitable for preventing it from becoming.

1 is a view schematically showing a method for manufacturing a semiconductor device according to the prior art;

2A through 2C are cross-sectional views illustrating a method of manufacturing a semiconductor device in accordance with a first embodiment of the present invention;

3A to 3C are cross-sectional views illustrating a method of manufacturing a semiconductor device in accordance with a second embodiment of the present invention;

4A to 4C are cross-sectional views illustrating a method of manufacturing a semiconductor device in accordance with a third embodiment of the present invention.

* Explanation of symbols for the main parts of the drawings

31 semiconductor substrate 32 gate oxide film

32a: GGO film 33a: polysilicon film

34a: tungsten nitride film 35a: tungsten nitride film

36a: tungsten film 38: oxide film

A method of manufacturing a semiconductor device of the present invention for achieving the above object comprises the steps of forming a gate oxide film on a semiconductor substrate, forming a polysilicon film on the gate oxide film, forming a tungsten silicon nitride film on the polysilicon film Forming a tungsten film on the tungsten silicon nitride film; patterning the tungsten film, the tungsten silicon nitride film, and the polysilicon film sequentially to form a gate electrode; and forming the gate electrode after forming the gate electrode. Selectively reoxidizing the oxide film.

In addition, the method of manufacturing a semiconductor device of the present invention comprises the steps of forming a gate oxide film on a semiconductor substrate, forming a polysilicon film on the gate oxide film, forming a tungsten silicide film on the polysilicon film, on the tungsten silicide film Forming a tungsten nitride film and a tungsten film in order, patterning the tungsten film, tungsten nitride film, tungsten silicide film and the polysilicon film sequentially to form a gate electrode, and forming the gate electrode after forming the gate electrode And performing a oxidation process to selectively reoxidize an oxide film to modify the tungsten silicide film into a tungsten silicon nitride film.

Hereinafter, the most preferred embodiments of the present invention will be described with reference to the accompanying drawings so that those skilled in the art can easily implement the technical idea of the present invention.

2A to 2C are cross-sectional views illustrating a method of manufacturing a semiconductor device in accordance with a first embodiment of the present invention.

As shown in FIG. 2A, the gate oxide film 22 is formed on the semiconductor substrate 21, and the polysilicon film 23 is formed on the gate oxide film 22. Here, as the gate oxide film 22, silicon oxide films such as SiO ₂ , SiO _x N _y , x = 0.03 to 3, y = 0.03 to 3), HfO ₂ , ZrO ₂ , Hf-Al-O, Hf-silicate, A high dielectric metal oxide containing hafnium (Hf) or zirconium (Zr) such as Zr-silicate is used.

Next, in order to remove the natural oxide film generated when the polysilicon film 23 is formed, washing is performed using a solution containing HF, and a tungsten silicon nitride film having a thickness of 30 kPa to 200 kPa is washed on the cleaned polysilicon film 23. After forming (WSi _x N _y ) 24, a tungsten film 25 of 300 mW to 1000 mW is continuously deposited.

At this time, the tungsten silicon nitride film 24 is a reaction barrier film between the tungsten film 25 and the polysilicon film 23, and is a tungsten-silicon target (W-Si target) or a tungsten-silicon source (W-Si source). It is formed by sputtering, chemical vapor deposition (CVD), atomic layer deposition (ALD).

For example, in the case of using the sputtering method, first, a mixed gas of argon (Ar) gas and nitrogen (N ₂ ) gas is supplied between the tungsten-silicon target and the semiconductor substrate 21 in the deposition chamber under a high voltage applied vacuum. The argon gas is ionized to form an argon plasma, and the Ar ⁺ ions constituting the plasma are accelerated by an electric field with a tungsten-silicon target to collide with the surface of the tungsten-silicon target. The surface atoms or molecules of the tungsten-silicon target are protruded by the exchange of momentum due to such collision, and the protruding atoms or molecules (Si ⁺ , W ⁺ ) are chemically reacted with nitrogen (N ₂ ) gas, which is a reactant gas, A tungsten silicon nitride film WSiN is deposited on the substrate 21, that is, on the polysilicon film 23.

When using the above-mentioned sputtering method, the flow amount of nitrogen gas is maintained at 5% to 40%, the power is maintained at 50W to 10000W, and the substrate temperature is maintained at 200 ° C to 400 ° C. The reason why the flow rate of nitrogen gas, that is, the nitrogen content in the tungsten silicon nitride film 24 is maintained at 40% or less is because the lower the nitrogen content in the tungsten silicon nitride film 24, the lower the specific resistance.

Meanwhile, deposition of the tungsten silicon nitride film 24 and the tungsten film 25 is performed in-situ or ex-situ.

As shown in FIG. 2B, after the photosensitive film pattern 26 for gate patterning is formed on the tungsten film 25, the photosensitive film pattern 26 is used as an etch mask, and the tungsten film 25 and the tungsten silicon nitride film ( 24), the polysilicon film 23 is sequentially etched to form a gate electrode stacked in the order of the polysilicon film 23a, the tungsten silicon nitride film 24a, and the tungsten film 25a.

When forming the above-described gate electrode, a part of the gate oxide film 22 exposed by etching the polysilicon film 23a is damaged.

As shown in FIG. 2C, after the photoresist pattern 26 is removed, the H ₂ O or H ₂ -rich or H ₂ -rich temperature or 850 ° C. to 950 ° C. is used to recover the damage of the gate oxide layer 22. The selective reoxidation process is carried out in an O ₂ atmosphere. In the selective reoxidation process, the gate oxide film 22 positioned on the edge of the polysilicon film 23a and the semiconductor substrate 21 is modified into a GGO film 22a having an increased thickness than the initial deposition thickness. As the exposed side of the film 23a is oxidized, an oxide film 27 is formed on the side of the polysilicon film 23a.

Here, the GGO film 22a is formed to have a thickness that is greater than the initial deposition thickness and has a form that partially penetrates the edge of the polysilicon film 23a, and is also located at the lower portion of the polysilicon film 23a. 22) thicker than that.

In the selective reoxidation process described above, the tungsten silicon nitride film 24a formed between the tungsten film 25a and the polysilicon film 23a suppresses the reaction between the tungsten film 25a and the polysilicon film 23a. It serves as a barrier film and maintains its shape and suppresses the formation of reactants such as silicon nitride film, silicon oxynitride film and silicon oxide film at the interface between tungsten film 25a and polysilicon film 23a. .

In a subsequent process, although not shown in the drawing, a low concentration impurity ion implantation for forming an LDD region is performed, and a high concentration impurity ion implantation for forming a source / drain region is formed after forming a spacer in contact with both side walls of the gate electrode pattern. Conduct.

Then, an interlayer insulating film is formed to insulate each transistor, and a metallization process is performed to connect the source, drain, and gate electrodes with external terminals.

3A to 3C are cross-sectional views illustrating a method of manufacturing a semiconductor device in accordance with a second embodiment of the present invention.

As shown in FIG. 3A, the gate oxide film 32 is formed on the semiconductor substrate 31, and the polysilicon film 33 is formed on the gate oxide film 32. Here, as the gate oxide film 32, silicon oxide films such as SiO ₂ , SiO _x N _y , x = 0.03 to 3, y = 0.03 to 3), HfO ₂ , ZrO ₂ , Hf-Al-O, Hf-silicate, A high dielectric metal oxide containing hafnium (Hf) or zirconium (Zr) such as Zr-silicate is used.

Next, in order to remove the natural oxide film generated when the polysilicon film 33 is formed, a cleaning using a solution containing HF is performed, and a tungsten silicon nitride film having a thickness of 30 kPa to 200 kPa is formed on the cleaned polysilicon film 33. (WSi _x N _y ) 34 is formed. Subsequently, a tungsten nitride film (WN _x ) 35 and a tungsten film 36 having a thickness of 30 kPa to 200 kPa are sequentially formed on the tungsten silicon nitride film 34.

Here, the tungsten silicon nitride film 34 and the tungsten nitride film 35 are reaction barrier films between the tungsten film 36 and the polysilicon film 33.

First, the tungsten silicon nitride film 34 is formed by sputtering, chemical vapor deposition, or atomic layer deposition using a tungsten-silicon target (W-Si target) or a tungsten-silicon source (W-Si source).

For example, in the case of using the sputtering method, first, a mixed gas of argon (Ar) gas and nitrogen (N ₂ ) gas is supplied between the tungsten-silicon target and the semiconductor substrate 31 in the deposition chamber under a high voltage applied vacuum. The argon gas is ionized to form an argon plasma, and the Ar ⁺ ions constituting the plasma are accelerated by an electric field with a tungsten-silicon target to collide with the surface of the tungsten-silicon target. The surface atoms or molecules of the tungsten-silicon target are protruded by the exchange of momentum due to such collision, and the protruding atoms or molecules (Si ⁺ , W ⁺ ) are chemically reacted with nitrogen (N ₂ ) gas, which is a reactant gas, A tungsten silicon nitride film WSiN is deposited on the substrate 31, that is, on the polysilicon film 33.

When using the above-mentioned sputtering method, the flow amount of nitrogen gas is maintained at 5% to 40%, the power is maintained at 50W to 10000W, and the substrate temperature is maintained at 200 ° C to 400 ° C. The reason why the flow rate of nitrogen gas, that is, the nitrogen content in the tungsten silicon nitride film 34 is maintained at 40% or less is because the lower the nitrogen content in the tungsten silicon nitride film 34, the lower the specific resistance. The flow amount of nitrogen gas provides a level similar to the specific resistance of the tungsten nitride film 35.

On the other hand, the deposition of the tungsten silicon nitride film 34, the tungsten nitride film 35 and the tungsten film 36 takes place in-situ or ex-situ.

As described above, the tungsten nitride film 35 is formed by inserting a laminate of the tungsten silicon nitride film 34 and the tungsten nitride film 35 as the reaction barrier film between the polysilicon film 33 and the tungsten film 36. When only 35 is inserted, the reactants are prevented from being formed at the interface between the polysilicon film 33 and the tungsten nitride film 35.

For example, although the tungsten nitride film is inserted as the reaction barrier film, the polysilicon film 33 and the tungsten nitride film 35 are subsequently subjected to the selective reoxidation process because it is a high temperature oxidation process containing an O ₂ or H ₂ O component. It is highly likely that a reactant such as SiON is formed at the interface of). Therefore, the formation of SiON is further suppressed by inserting the tungsten silicon nitride film 34 further.

As shown in FIG. 3B, after the photosensitive film pattern 37 for gate patterning is formed on the tungsten film 36, the tungsten film 36 and the tungsten nitride film 35 are formed using the photosensitive film pattern 37 as an etching mask. ), The tungsten silicon nitride film 34 and the polysilicon film 33 are sequentially etched to form the polysilicon film 33a, the tungsten silicon nitride film 34a, the tungsten nitride film 35a, and the tungsten film 36a. The stacked gate electrodes are formed in the order of.

When forming the above-described gate electrode, a portion of the gate oxide film 32 exposed by etching the polysilicon film 33a is damaged.

A, after removing the photoresist pattern 37, in order to restore damage to the gate oxide film 32, the temperature and the hydrogen of 850 ℃ ~950 ℃ many (H ₂ -rich) as shown in Figure 3c H ₂ O or The selective reoxidation process is carried out in an O ₂ atmosphere. In the selective reoxidation process, the gate oxide film 32 positioned on the edge of the polysilicon film 33a and the semiconductor substrate 31 is modified into a GGO film 32a having an increased thickness than the initial deposition thickness. As the exposed side of the film 33a is oxidized, an oxide film 38 is formed on the side of the polysilicon film 33a.

Here, the GGO film 32a is formed to have a thickness that is greater than the initial deposition thickness, and has a form that partially penetrates the edge of the polysilicon film 33a, and is also located at the lower portion of the polysilicon film 33a. 32) thicker than that.

In the selective reoxidation process described above, the tungsten silicon nitride film 34a formed between the tungsten nitride film 35a and the polysilicon film 33a suppresses the reaction between the tungsten film 36a and the polysilicon film 33a. And a reactant such as a silicon nitride film, a silicon oxynitride film, or a silicon oxide film is formed at the interface between the tungsten nitride film 35a and the polysilicon film 33a while maintaining its shape. Suppress what happens.

In a subsequent process, although not shown in the drawing, a low concentration impurity ion implantation for forming an LDD region is performed, and a high concentration impurity ion implantation for forming a source / drain region is formed after forming a spacer in contact with both side walls of the gate electrode pattern. Conduct.

Then, an interlayer insulating film is formed to insulate each transistor, and a metallization process is performed to connect the source, drain, and gate electrodes with external terminals.

4A through 4C are cross-sectional views illustrating a method of manufacturing a semiconductor device in accordance with a third embodiment of the present invention.

As shown in FIG. 4A, the gate oxide film 42 is formed on the semiconductor substrate 41, and the polysilicon film 43 is formed on the gate oxide film 42. Here, as the gate oxide film 42, silicon oxide films such as SiO ₂ , SiO _x N _y , x = 0.03 to 3, y = 0.03 to 3), HfO ₂ , ZrO ₂ , Hf-Al-O, Hf-silicate, A high dielectric metal oxide containing hafnium (Hf) or zirconium (Zr) such as Zr-silicate is used.

Next, in order to remove the natural oxide film generated when the polysilicon film 43 is formed, washing is performed using a solution containing HF, and a tungsten silicide film (W) having a thickness of 50 kPa to 200 kPa is formed on the cleaned polysilicon film 43. _x Si _y ) 44 is formed. Subsequently, a tungsten nitride film 45 and a tungsten film 46 having a thickness of 30 kPa to 200 kPa are sequentially formed on the tungsten silicide film 44.

First, the tungsten silicide layer 44 is formed by sputtering, chemical vapor deposition, or atomic layer deposition using a tungsten-silicon target (W-Si target) or a tungsten-silicon source (W-Si source).

For example, in the case of using the sputtering method, first, argon (Ar) gas is supplied between the tungsten-silicon target in the deposition chamber and the semiconductor substrate 31 in a vacuum under high voltage, and then the argon gas is ionized to form an argon plasma. Ar ⁺ ions constituting the plasma are accelerated by an electric field with a tungsten-silicon target to collide with the surface of the tungsten-silicon target. The surface atoms or molecules of the tungsten-silicon target are protruded by the exchange of momentum due to such collision, and the protruding atoms or molecules (Si ⁺ , W ⁺ ) are chemically reacted to form the semiconductor substrate 41, that is, the polysilicon film ( 43, a tungsten silicide film WSi is deposited.

When using the above-mentioned sputtering method, the power is maintained at 50W to 10000W and the substrate temperature is maintained at 200 ° C to 400 ° C.

On the other hand, the deposition of the tungsten silicide film 44, the tungsten nitride film 45 and the tungsten film 46 takes place in-situ or ex-situ.

As shown in FIG. 4B, after the photosensitive film pattern 47 for gate patterning is formed on the tungsten film 46, the tungsten film 46 and the tungsten nitride film 45 are formed by using the photosensitive film pattern 47 as an etching mask. ), The tungsten silicon nitride film 44 and the polysilicon film 43 are sequentially etched in order of the polysilicon film 43a, the tungsten silicide film 44a, the tungsten nitride film 45a, and the tungsten film 46a. The stacked gate electrodes are formed.

When forming the above-described gate electrode, a part of the gate oxide film 42 exposed by etching the polysilicon film 43a is damaged.

As shown in FIG. 4C, after the photoresist pattern 47 is removed, a temperature of 850 ° C. to 950 ° C. and H ₂ O-rich or H ₂ -rich to recover damage of the gate oxide film 42 or The selective reoxidation process is carried out in an O ₂ atmosphere. In the selective reoxidation process, the gate oxide film 42 positioned on the edge of the polysilicon film 43a and on the semiconductor substrate 41 is modified into a GGO film 42a having an increased thickness than the initial deposition thickness. As the exposed side of the film 43a is oxidized, an oxide film 48 is formed on the side of the polysilicon film 43a.

Here, the GGO film 42a is formed to have a thickness that is greater than the initial deposition thickness, and has a form that partially penetrates the edge of the polysilicon film 43a and is also located at the lower portion of the polysilicon film 43a. 42) thicker than that.

In the selective reoxidation process described above, the tungsten silicide film 44a formed between the tungsten nitride film 45a and the polysilicon film 43a is modified with the tungsten silicon nitride film 44b. This is because nitrogen in the tungsten nitride film 45a diffuses into the tungsten silicide film 44a during the selective reoxidation process. On the other hand, the nitrogen content in the tungsten silicon nitride film 44b is maintained at 5% to 40%.

As a result, in the above-described selective reoxidation process, the tungsten silicon nitride film 44b formed between the tungsten nitride film 45a and the polysilicon film 43a is formed between the tungsten film 46a and the polysilicon film 43a. It serves as a reaction barrier film that suppresses the reaction, and also maintains its shape at the interface between the tungsten nitride film 45a and the polysilicon film 43a, such as a silicon nitride film, a silicon oxynitride film, and a silicon oxide film. Suppresses the formation of reactants.

In a subsequent process, although not shown in the drawing, a low concentration impurity ion implantation for forming an LDD region is performed, and a high concentration impurity ion implantation for forming a source / drain region is formed after forming a spacer in contact with both side walls of the gate electrode pattern. Conduct.

Then, an interlayer insulating film is formed to insulate each transistor, and a metallization process is performed to connect the source, drain, and gate electrodes with external terminals.

On the other hand, although the tungsten film is taken as the metal gate electrode film as an example in the first, second and third embodiments described above, it is also applicable to the case where other metal films are applied.

Although the technical idea of the present invention has been described in detail according to the above preferred embodiment, it should be noted that the above-described embodiment is for the purpose of description and not of limitation. In addition, those skilled in the art will understand that various embodiments are possible within the scope of the technical idea of the present invention.

The present invention as described above has the effect of improving the reliability of the semiconductor device by suppressing the formation of the oxide film or the reaction layer at the interface between the polysilicon film and the metal film in the subsequent selective reoxidation and thermal process of the subsequent oxidation atmosphere.

Claims (11)

Forming a gate oxide film on the semiconductor substrate; Forming a polysilicon film on the gate oxide film; Forming a tungsten silicon nitride film on the polysilicon film; Forming a tungsten film on the tungsten silicon nitride film; Sequentially forming the tungsten film, the tungsten silicon nitride film and the polysilicon film to form a gate electrode; And Selectively reoxidizing the gate oxide film exposed after the gate electrode is formed; Method of manufacturing a semiconductor device, characterized in that it comprises a. The method of claim 1, In the step of forming the tungsten silicon nitride film, The method of manufacturing a semiconductor device, characterized in that the nitrogen content in the tungsten silicon nitride film is 5% to 40%. The method of claim 1, After forming the tungsten silicon nitride film, And forming a tungsten nitride film on the tungsten silicon nitride film. The method of claim 3, And the tungsten silicon nitride film, the tungsten nitride film and the tungsten film are formed in-situ or ex-situ. The method of claim 1, Forming the tungsten silicon nitride film, A sputtering method using a tungsten-silicon target, or a chemical vapor deposition method or an atomic layer deposition method using a tungsten-silicon source. The method of claim 5, Sputtering method using the tungsten-silicon target, A mixture of nitrogen gas and argon gas is used, and the power is maintained at 50W to 10000W, and the substrate temperature is maintained at 200 ° C to 400 ° C, but the flow rate of the nitrogen gas is maintained at 5% to 40%. A semiconductor device manufacturing method. The method of claim 1, The tungsten silicon nitride film is formed to a thickness of 30 ~ 200 Å semiconductor device manufacturing method. Forming a gate oxide film on the semiconductor substrate; Forming a polysilicon film on the gate oxide film; Forming a tungsten silicide film on the polysilicon film; Sequentially forming a tungsten nitride film and a tungsten film on the tungsten silicide film; Sequentially forming the tungsten film, the tungsten nitride film, the tungsten silicide film and the polysilicon film to form a gate electrode; And Modifying the tungsten silicide film to a tungsten silicon nitride film by performing an oxidation process to selectively reoxidize the gate oxide film exposed after the gate electrode is formed. Method of manufacturing a semiconductor device, characterized in that it comprises a. The method of claim 8, Forming the tungsten silicide film, A sputtering method using a tungsten-silicon target, or a chemical vapor deposition method or an atomic layer deposition method using a tungsten-silicon source. The method of claim 8, The tungsten silicon nitride film is formed by diffusion of nitrogen in the tungsten nitride film, the nitrogen content in the tungsten silicon nitride film is a method of manufacturing a semiconductor device, characterized in that 5% to 40%. The method of claim 8, An oxidation process for selectively reoxidizing the gate oxide film, A method of manufacturing a semiconductor device, characterized in that the hydrogen is composed of H ₂ O or O ₂ atmosphere at a temperature of 850 ℃ to 950 ℃.