JPH09186104A - Manufacture of semiconductor device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent degradation of characteristics of an element due to high- temperature processing by forming a high melting-point metal silicide layer for a fine element. SOLUTION: A first high melting-point metal film 107 is deposited on silicon substrates 101 and 104, and a second high melting-point metal film 108 containing nitrogen is formed on the first high melting-point metal film 107. Thereafter, heat processing is performed in an atmosphere not containing nitrogen to form a silicide layer 109. The nitrogen from the second high melting-point metal film 108 is diffused into the first high melting-point metal film 107 to promote nitriding reaction of titanium, and to suppress overgrowth due to the reaction between the diffused silicon and the titanium. Further, even when the film thickness of the high melting-point metal film is reduced, the nitriding reaction of the high melting-point metal film is suppressed in a region in contact with the silicon. Thus, a silicide layer having a preferably thickness and a uniformed layer resistance is formed.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method of manufacturing a semiconductor device, and more particularly, to a silicide of a refractory metal in a self-aligned manner on a surface of a diffusion layer or a gate electrode of an insulated gate field effect transistor (hereinafter referred to as a MOS transistor). It relates to a method of forming a layer.

[0002]

2. Description of the Related Art With the miniaturization and high density of semiconductor elements,
Currently, ultra-highly integrated semiconductor devices such as memory devices and logic devices designed on the basis of a size of 0.15 to 0.25 μm are provided. With the high integration of such semiconductor devices, it is required to reduce the gate electrode length of MOS transistors, the width of diffusion layers such as source / drain, and the film thickness of these. However, the reduction of the gate electrode length, the width of the diffusion layer, and the reduction of the film thickness inevitably lead to an increase in the electric resistance of these, and have a great influence on the delay of the circuit. Therefore, in the miniaturized device, it is an essential technique to reduce the resistance of the gate electrode using the refractory metal silicide. In particular, salicide using titanium metal as the refractory metal (Self-align
-Silicide) technology has become an important technology for fine MOS transistors. Further, in the MOS transistor having such a structure, it is necessary to suppress the diffusion of impurities forming the diffusion layer to suppress the short channel effect of the transistor in accordance with the tendency of higher integration of the semiconductor device. As a result, when the junction surface of the diffusion layer comes into contact with the silicide region layer, the crystal defect leak current increases and the switching operation of the transistor becomes impossible. Therefore, the thinning of the silicide layer becomes essential as the diffusion layer becomes shallower.

10 and 11 are shown in Japanese Patent Laid-Open No. 3-65658.
FIG. 6 is a diagram showing a method of manufacturing a MOS transistor described in Japanese Patent Publication in the order of steps, particularly a method of forming a salicide thereof. First, as shown in FIG. 10A, the element isolation insulating film 102 is formed in a predetermined region of the silicon substrate 101 by the LOCOS method. Next, the silicon substrate 101
Although not shown, the impurity for the channel stopper is ion-implanted around the element region. Further, a gate insulating film 103 is formed on the surface of the silicon substrate 101 by a thermal oxidation method, and then a film thickness of 150 n is formed on the entire surface by a CVD method.
A polysilicon film of about m is formed, and impurities such as phosphorus are doped to reduce the resistance. After that, pattern formation is performed by the photolithography technique to form the gate electrode 104. Then, a silicon oxide film is deposited on the entire surface by the CVD method, and the silicon oxide film is etched by anisotropic etching to obtain the gate electrode 10.
The spacer 105 is formed on the side surface of No. 4. Then, impurities such as arsenic and boron are ion-implanted into the silicon substrate 101, and a diffusion layer 106 as a source / drain region is formed by heat treatment at 800 to 1000 ° C.

Next, as shown in FIG. 10B, a titanium film 107 having a thickness of about 50 nm is formed on the entire surface by a sputtering method. Then, heat treatment is carried out at a temperature of 600 to 650 ° C. for 30 seconds to 60 seconds using a lamp annealing device or the like in a nitrogen atmosphere at atmospheric pressure. As a result, the titanium film 107 undergoes a silicidation reaction in a region in contact with silicon such as the gate electrode 104 and the diffusion layer 106,
As shown in FIG. 10C, the titanium silicide layer 109 is formed on the interface. Hereinafter, this heat treatment is referred to as the first heat treatment. This titanium silicide layer 109 has a thickness of 60 μΩ.
This is a C49 structure titanium silicide layer having a crystal structure with a high electrical resistivity of about cm. In addition, by the first heat treatment,
The titanium film 107 is a titanium nitride film (TiN) 108B in which the composition ratio of titanium and nitrogen is 1: 1.

Thereafter, as shown in FIG. 11 (a), the titanium silicide film 108B which has not been silicidized is removed by etching with a chemical solution in which an aqueous ammonia solution and a hydrogen peroxide solution are mixed. Thereby, the titanium silicide layer 109
Only is left on the surface of the silicon. Further, when the second heat treatment at about 850 ° C. is performed for about 60 seconds in a nitrogen atmosphere at normal pressure, the titanium silicide layer 109 having the C49 structure described above has an electrical conductivity of about 20 μΩ · cm as shown in FIG. 11B. It can be changed to a titanium silicide layer 111 having a C54 structure having a low resistivity crystalline structure. Hereinafter, this heat treatment is referred to as the second heat treatment.

Further, as a method of forming a silicide in another MOS transistor, for example, Japanese Patent Laid-Open No. 3-735 is known.
There is a technique described in Japanese Patent No. 33. This manufacturing method is shown in FIG.
12A, after forming the element isolation insulating film 102, the gate oxide film 103, the gate electrode 104, and the stopper 105 on the silicon substrate 101, as shown in FIG. As shown in b), a titanium film 107 having a thickness of 20 nm and a titanium nitride film 108C are formed in a laminated state on the entire surface by a sputtering method using an argon gas. Then, the first heat treatment is performed in a nitrogen atmosphere to form a titanium silicide layer 109 at the interface between the silicon and the titanium film 107 as shown in FIG. At this time, the titanium nitride film 108 is formed on the titanium film 107.
Since the heat treatment is performed in a nitrogen atmosphere in the presence of C, titanium oxide is not formed on the surface of the titanium film 107, and the layer resistance can be reduced (15 μΩ · cm). After that, as shown in FIGS. 13A and 13B, the titanium nitride film 108C and the nitrogen-diffused titanium film 107 are removed by an aqueous ammonia solution, and a second heat treatment is performed to change the C49 structure to the C54 structure of titanium. Silicide layer 1
By changing to 11, a titanium silicide layer is formed.

[0007]

The reason why the titanium silicide layer 109 is formed in a nitrogen atmosphere in each of the above techniques is as follows. In the silicide reaction of titanium and silicon, the diffusion species is silicon. Here, silicon is diffused also on the oxide film such as the element isolation insulating film 102, and when the silicon diffused on the oxide film reacts with titanium, a titanium silicide layer is formed also on the oxide film. As a result, insulation due to the oxide film becomes defective and so-called overgrowth occurs. In order to prevent this, heat treatment is performed in a nitrogen atmosphere to react titanium with nitrogen and form titanium nitride. Since the reaction temperature of this titanium nitride is lower than the silicide reaction temperature, the titanium on the oxide film is consumed in the film formation of titanium nitride, does not react with silicon, and the above titanium silicide layer is not formed. This allows the titanium silicide layer to be formed in a self-aligned manner only in the silicon region.

However, such a conventional manufacturing method is effective in forming the titanium silicide layer in a self-aligned manner, but when the titanium silicide layer is thinned as the semiconductor device is miniaturized, There is a problem that the titanium silicide layer may not be manufactured appropriately. That is, with the miniaturization of semiconductor devices, it is required to reduce the thickness of the titanium film for forming the titanium silicide layer. Here, if the titanium film is thinned, the nitriding reaction and the silicide reaction in titanium are likely to compete with each other. In particular, when arsenic impurities are present in silicon, the silicide reaction rate is reduced, the nitriding reaction is relatively increased, and as a result, the thickness of the silicide layer is extremely reduced. In some cases, titanium is completely consumed in the nitriding reaction,
This also occurs when the silicide layer is not formed.

For example, if the titanium film thickness is thicker than 30 to 50 nm, which is the depth at which nitrogen can diffuse into titanium at 700 ° C., the silicide reactions of the titanium film are independently formed without competition. However, when the titanium film thickness is reduced to 30 to 50 nm or less, which is the depth at which nitrogen can diffuse, the effect of the reaction rate of the titanium silicide reaction and the titanium nitride reaction affects the film thickness. Furthermore, when impurities are contained in silicon, the silicidation reaction is suppressed, and especially when arsenic is contained in silicon,
When the silicide reaction speed is reduced and the titanium film thickness is made thinner than the above-mentioned film thickness, the reaction speed of titanium nitride formation is relatively increased rather than the silicide reaction, and as a result, the silicide film thickness is extremely reduced. Will be done.

Further, in the latter prior art, since the titanium nitride films are laminated, the following problems occur.
That is, the silicide reaction in the region surrounded by the insulating film causes a phenomenon in which the silicide layer itself sinks into silicon as the silicide layer is formed. This is due to silicon diffusion caused by the silicide reaction. Furthermore, when the subsidence of the silicide layer occurs, the titanium film and the titanium nitride film are also plastically deformed as the silicide is deformed. At this point, in silicon having a narrow line width, the span length supported by the insulating film is reduced, so that the force required for plastic deformation of the refractory metal film of the titanium film and the titanium nitride film is increased. Due to the increase in the structural strength of the refractory metal film in the formation of the silicide in the thin line, the refraction of the refractory metal film is suppressed, and the silicide reaction rate is reduced. Due to the decrease in the silicide reaction rate in this thin line, the formation reaction of titanium nitride, which is a competitive reaction, becomes predominant, and silicide is not formed and only titanium nitride is formed.

Further, titanium nitride is a substance which is difficult to be etched, and particularly in a method including a step of performing heat treatment after forming a titanium nitride film as in the above-mentioned conventional method, titanium nitride is sintered by this heat treatment, The film strength is particularly high and the titanium nitride film is highly uniform. As a result, titanium can be removed with a mixed solution of ammonia, but it becomes difficult to remove the titanium nitride film by etching. For this reason, steps such as over-etching and dry-etching the titanium nitride film are added. However, since the etching selection ratio between titanium silicide and titanium nitride is low in either etching, the thin film silicide Since the layer is etched, variation in layer resistance increases, and the layer thickness of the silicide layer becomes extremely thin, which makes it difficult to reduce the layer resistance.

An object of the present invention is to provide a method of manufacturing a semiconductor device which enables formation of a refractory metal silicide layer on a fine element and prevents deterioration of characteristics of the element due to high temperature heat treatment. is there.

[0013]

According to the method of manufacturing a semiconductor device of the present invention, a refractory metal film is deposited on the surface of a silicon substrate and heat-treated to form a refractory metal silicide at the interface between silicon and the refractory metal film. In the method for manufacturing a semiconductor device for forming a layer, including the step of forming a refractory metal film containing nitrogen, which is the same refractory metal as the refractory metal film, on the refractory metal film,
The heat treatment is performed in an atmosphere containing no nitrogen atom. Alternatively, the method further comprises the step of thinly forming a nitrided refractory metal film of the same refractory metal on the refractory metal film, and the heat treatment is performed in an atmosphere containing no nitrogen atom. Here, the refractory metal film is preferably a titanium film, and the nitrided refractory metal film is preferably a titanium nitride film. The refractory metal film preferably has a thickness of 30 nm or less, and the nitride refractory metal film preferably has a thickness of 20 μm or less. Further, the atmosphere containing no nitrogen atom is an atmosphere of an inert gas such as argon or a vacuum atmosphere.

[0014]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Next, embodiments of the present invention will be described with reference to the drawings. 1 and 2 are sectional views showing a first embodiment of the present invention in the order of steps. First, FIG.
As shown in (a), the element isolation insulating film 102 is formed by a LOCOS method in a predetermined region of the silicon substrate 101 in which the P conductivity type or the P well is formed. Impurities for channel stoppers (not shown) are ion-implanted into the element region of the silicon substrate 101, and a gate insulating film 103 having a thickness of about 8 nm is formed thereon by thermal oxidation.

Next, a film thickness of 100 is formed on the entire surface by the CVD method.
A polysilicon film of about nm is formed, and impurities such as phosphorus are doped to reduce the resistance. After that, pattern formation is performed by the photolithography technique to form the gate electrode 104. Then, the film thickness is 1 on the entire surface by the CVD method.
A spacer 105 is formed on the side surface of the gate electrode 104 by depositing a silicon oxide film of about 00 nm and etching the silicon oxide film by anisotropic etching. Then, impurities such as arsenic and boron are ion-implanted into the silicon substrate 101, and the diffusion layer 10 as a source / drain region is subjected to heat treatment at about 900 temperature.
6 are formed. Here, the dose of arsenic ions is 1 ×
It is set to about 10 ¹⁵ ions / cm ² .

Next, as shown in FIG. 1B, a titanium film 107 having a thin film thickness of about 20 nm is formed on the entire surface by a sputtering method.
And a nitrogen-containing titanium film 108 is formed to a thickness of 50 nm.
It is formed to have a film thickness of about. Then, heat treatment is performed in an argon atmosphere at 700 ° C. for 30 seconds using a lamp annealing device or the like. As a result, the titanium film 107 undergoes a silicidation reaction in a region in contact with silicon such as the gate electrode 104 and the diffusion layer 106, and as shown in FIG. 1C, the interface has a C49 structure with a film thickness of 20 nm. The titanium silicide layer 109 is formed.

At this time, since the nitrogen-containing titanium film 108 is present on the titanium film 107 on the oxide film 102 constituting the element isolation insulating film, nitrogen from the nitrogen-containing titanium film 108 is converted to titanium during the heat treatment. The nitrogen-containing titanium film 110 is diffused in the film 107 and is deposited on the upper surface of the titanium film 107
Therefore, the nitriding reaction of titanium in the titanium film 107 is promoted, and overgrowth due to the reaction between the diffused silicon and titanium on the oxide film 102 is suppressed.

FIG. 3 shows the nitrogen-containing titanium film 110 after the argon heat treatment on the oxide film and the heat treatment in the nitrogen atmosphere.
3 shows the depth distribution of nitrogen atoms in the titanium film 107. In the heat treatment in the argon atmosphere, nitrogen is not supplied from the atmosphere, so that nitrogen is diffused into the titanium film 107, while the nitrogen concentration in the nitride-containing titanium film 108 is reduced. further,
In the heat treatment in the argon atmosphere, the diffusion depth of nitrogen in the titanium film 107 is shallower than that in the heat treatment in the nitrogen atmosphere. By suppressing the diffusion of nitrogen in the titanium film 107 in this way, the nitriding reaction of titanium in the region on the lower surface side where the titanium film 107 is in contact with silicon is suppressed. Therefore, as the device becomes finer, the titanium film 107
Even if the film thickness of is reduced, the required amount of titanium silicide reaction is secured in the contact area with silicon.
A silicide layer of suitable thickness is formed.

FIG. 4 shows the dependence of the layer resistance on the composition ratio of the nitrogen-containing titanium film. From this result, the composition ratio of nitrogen is 50%.
When it is set below, the layer resistance is stabilized to 10 Ω or less. It is considered that this is due to the fact that the silicide reaction becomes dominant due to the nitriding reaction of titanium, and the film strength of the titanium nitride film is weakened by about one digit. On the other hand, the lower limit of the nitrogen content is limited by the overgrowth of the silicide. FIG. 5 shows the result of examining the overgrowth by the leak current flowing between the gate and the diffusion layer, and the dependence of the read current of the gate and the diffusion layer on the composition ratio of the non-defective nitrogen containing titanium film. If the composition ratio of nitrogen is 30% or less,
The silicide cannot be formed in a self-aligned manner, the leak current between the gate and the diffusion layer increases, and the non-defective rate decreases. Therefore, it is understood that the case where the composition ratio of nitrogen is 30% to 50% is the condition under which the layer resistance can be made the lowest and the self-aligned silicide in which the leak current between the gate and the diffusion layer does not occur can be formed.

After that, as shown in FIG. 2A, the nitrogen-containing titanium film 108 and the nitrogen-containing titanium film 110 are removed by etching with a chemical solution in which an aqueous ammonia solution and a hydrogen peroxide solution are mixed. Thereby, the titanium silicide layer 10
Only 9 is left on the surface of silicon such as the gate electrode 104 and the diffusion layer 106. Here, FIG. 6 shows the dependence of the etching rate of the nitrogen-containing titanium film 108 on the flow ratio of nitrogen and argon in the sputtering process of the nitrogen-containing titanium film.
The etching rate of the nitrogen-containing titanium film 108 can be increased from 0.6 nm / min to 8 nm / min or more when the flow rate ratio of nitrogen and argon is set to about 1: 1. Therefore, since the etching rate of silicide is 2 nm / min, the selectivity with respect to silicide can be improved by using the nitrogen-containing titanium film from the state where the selectivity between titanium nitride and silicide was 1 or less. This improves the uniformity of the film thickness of the thin film silicide.

After that, when a second heat treatment at about 800 ° C. is performed for 10 seconds in an argon atmosphere, the titanium silicide layer 109 having the C49 structure becomes the titanium silicide layer 111 having the C54 structure as shown in FIG. 2B. be changed.
As described above, in the first embodiment, the nitrogen-containing titanium film is formed on the titanium film, and the silicide layer is formed by heat treatment in the nitrogen-free atmosphere on the titanium film, so that overgrowth is suppressed. In addition, even if the film thickness of the titanium film is reduced with the miniaturization of the element, the nitriding reaction of titanium in the region on the lower surface side where the titanium film is in contact with silicon is suppressed, and the titanium film having a suitable thinness is formed. A silicide layer is formed and the uniformity of the film thickness is improved.

7 and 8 are sectional views showing a second embodiment of the present invention in the order of manufacturing steps. In this embodiment, the film strength of titanium nitride is lowered by reducing the film thickness of titanium nitride (TiN) in which the composition ratio of nitrogen and titanium is 1: 1. First, as shown in FIG. 7A, an element isolation insulating film 102 having a thickness of 300 nm is formed by a LOCOS method in a predetermined region of a silicon substrate 101 in which a P conductivity type or a P well is formed. In addition, the silicon substrate 10
An impurity for a channel stopper is ion-implanted into the first element region, and a gate insulating film 103 having a film thickness of about 8 nm is formed thereon by a thermal oxidation method.

Next, a film thickness of 100 is formed on the entire surface by the CVD method.
A polysilicon film of about nm is formed, and impurities such as phosphorus are doped to reduce the resistance. After that, pattern formation is performed by the photolithography technique to form the gate electrode 104. Then, the film thickness is 100n by the CVD method.
A silicon oxide film is deposited on the entire surface of about m, and the silicon oxide film is etched by anisotropic etching to form a spacer 105 on the side surface of the gate electrode 104. Then, impurities such as arsenic and boron are ion-implanted into the silicon substrate 101, and the diffusion layer 10 as a source / drain region is subjected to heat treatment at about 900 temperature.
6 are formed.

Then, as shown in FIG. 7B, a titanium film 107 having a thin film thickness of about 20 nm is formed on the entire surface by a sputtering method.
Is formed. Subsequently, as shown in FIG. 7C, a titanium nitride film 108A is formed with a thin film thickness of 15 nm. Then, as shown in FIG. 8A, 700 ° C. in an argon gas atmosphere.
Heat treatment is performed at 30 ° C. for 30 seconds. As a result, the gate electrode 104 and the diffusion layer 1 are formed on the lower surface of the titanium film 107.
A silicidation reaction is performed in a region in contact with silicon such as 06, and a titanium silicide layer 109 having a C49 structure is formed at the interface. At this time, the element isolation insulating film 1
On the oxide film such as 02, since the titanium film 107 is formed as the nitrogen-containing titanium film 110, the nitriding reaction of titanium in the nitrogen-containing titanium film 110 is promoted and the diffused silicon and titanium are oxidized. Overgrowth due to the above reaction is suppressed.

FIG. 9 shows the titanium nitride film thickness dependence of the silicide layer resistance. The thickness of the titanium nitride film 108A is 20 nm.
By the following, the layer resistance of the silicide can be reduced to 10 ohm / sq up to the line width of 0.2 μm. The reason for this is that silicide reaction can be formed because the reaction of silicide is superior to the film strength of titanium nitride with a line width of 0.2 μm. Therefore, it is necessary to reduce the film thickness of the titanium nitride 108A as the line width becomes thinner. Thereafter, as shown in FIG. 8B, the titanium nitride film 108A is removed by etching with a chemical solution in which an aqueous ammonia solution and a hydrogen peroxide solution are mixed. As a result, only the titanium silicide layer 109 is left on the surface of silicon. Further, when a second heat treatment at about 800 ° C. is performed for 10 seconds in an argon atmosphere, the titanium silicide layer 1 having the above-mentioned C49 structure is formed.
09 is converted into a titanium silicide layer 111 having a C54 structure.

In the second embodiment, the titanium nitride film 1 is used.
The silicide reaction rate is improved by reducing the film thickness of 08A. Further, the titanium nitride film can be easily removed by etching, and the layer resistance can be stabilized without etching the thin silicide layer.

Here, in each of the above embodiments, the silicidation reaction is performed in an argon atmosphere, but an atmosphere of an inert gas, for example, a gas atmosphere of neon, helium, or the like,
Alternatively, the present invention can be similarly applied in a vacuum atmosphere. Further, as the refractory metal, it is possible to use other metals such as tungsten and molybdenum in addition to the above-mentioned titanium.

[0028]

As described above, according to the present invention, a refractory metal film containing nitrogen, which is the same refractory metal as the refractory metal film formed on a silicon substrate, is formed on the refractory metal film. Since the refractory silicide layer is formed by heat treatment in an atmosphere containing no atoms, overgrowth on the oxide film is suppressed and even when the film thickness of the titanium film is reduced as the element is miniaturized. , The nitriding reaction of titanium in the region on the lower surface side where the titanium film is in contact with silicon is suppressed, and a silicide layer having a suitable thickness is formed.
Moreover, the uniformity of the film thickness is improved. Moreover, since the nitrided refractory metal film is thinly formed on the refractory metal film and the refractory silicide layer is formed by heat treatment in an atmosphere containing no nitrogen atom, the overgrowth is suppressed, The silicide reaction rate is improved, the titanium nitride film is easily removed by etching, and the layer resistance can be stabilized without etching the thin silicide layer.

[Brief description of the drawings]

FIG. 1 is a first cross-sectional view showing the manufacturing method of the first embodiment of the present invention in the order of steps.

FIG. 2 is a second sectional view showing the manufacturing method according to the first embodiment of the present invention in the order of steps;

FIG. 3 is a diagram showing a comparison of diffusion depths of nitrogen atoms after heat treatment in an argon atmosphere and a nitrogen atmosphere.

FIG. 4 is a diagram showing the composition ratio dependence of nitrogen-containing titanium in sputtering.

FIG. 5 is a diagram showing the dependence of the non-defective rate on the nitrogen composition ratio.

FIG. 6 is a diagram showing the dependence of the etching rate of nitrogen-containing titanium on the nitrogen composition ratio.

FIG. 7 is a first sectional view showing the manufacturing method according to the second embodiment of the present invention in the order of steps;

FIG. 8 is a second sectional view illustrating the manufacturing method according to the second embodiment of the present invention in the order of steps;

FIG. 9 is a diagram showing the dependency of silicide layer resistance on the titanium nitride film thickness.

FIG. 10 is a first sectional view showing an example of the conventional manufacturing method in the order of steps.

FIG. 11 is a second sectional view showing an example of the conventional manufacturing method in the order of steps.

FIG. 12 is a first sectional view showing another example of the conventional manufacturing method in the order of steps.

FIG. 13 is a second sectional view showing another example of the conventional manufacturing method in the order of steps.

[Explanation of symbols]

 101 silicon substrate 102 element isolation insulating film 103 gate oxide film 104 gate electrode 105 stopper 106 diffusion layer 107 titanium film 108, 108A to 108C titanium nitride film 109 C49 structure silicide layer 110 nitrogen-containing titanium film 111 C54 structure silicide layer

Claims (7)

[Claims] 1. A method for manufacturing a semiconductor device, comprising: depositing a refractory metal film on a surface of a silicon substrate and performing heat treatment to form a refractory metal silicide layer at an interface between silicon and the refractory metal film. A method of manufacturing a semiconductor device, comprising the step of forming a refractory metal film of the same refractory metal and containing nitrogen on a metal film, wherein the heat treatment is performed in an atmosphere containing no nitrogen atoms. 2. A step of forming an oxide film for element isolation and a gate oxide film on a silicon substrate, forming a gate electrode on the gate oxide film, and a step of forming a stopper made of an insulating film on a side surface of the gate electrode. A step of introducing impurities into the silicon substrate to form source / drain diffusion layers, a step of depositing a first refractory metal film on the entire surface, and a step of depositing a first refractory metal on the same. And depositing a second refractory metal film containing nitrogen, and performing heat treatment in an atmosphere not containing nitrogen atoms to form a high temperature at a contact interface between the first refractory metal film and the gate electrode and the diffusion layer. A semiconductor including: a step of forming a melting point metal silicide layer; a step of removing the first and second refractory metal films; and a step of performing a heat treatment to cause a phase transition of the refractory metal silicide layer. Device manufacturing method. 3. A method of manufacturing a semiconductor device, comprising: depositing a refractory metal film on a surface of a silicon substrate and performing heat treatment to form a refractory metal silicide layer at an interface between silicon and the refractory metal film. A method of manufacturing a semiconductor device, comprising the step of thinly forming a nitrided refractory metal film of the same refractory metal on a metal film, wherein the heat treatment is performed in an atmosphere containing no nitrogen atoms. 4. A step of forming an oxide film for element isolation and a gate oxide film on a silicon substrate, forming a gate electrode on the gate oxide film, and a step of forming a stopper made of an insulating film on a side surface of the gate electrode. A step of introducing impurities into the silicon substrate to form source / drain diffusion layers, a step of depositing a refractory metal film on the entire surface, and a step of nitriding the same refractory metal on the refractory metal film. Forming a thin refractory metal film; forming a refractory metal silicide layer at a contact interface between the refractory metal film and the gate electrode and the diffusion layer by performing heat treatment in a nitrogen-free atmosphere; A step of removing the melting point metal film and the nitride refractory metal film,
And a step of performing a phase transition on the refractory metal silicide layer by heat treatment. 5. The method of manufacturing a semiconductor device according to claim 3, wherein the refractory metal film is a titanium film and the nitrided refractory metal film is a titanium nitride film. 6. The method for manufacturing a semiconductor device according to claim 3, wherein the refractory metal film has a film thickness of 30 nm or less, and the nitrided refractory metal film has a film thickness of 20 μm or less. 7. The method of manufacturing a semiconductor device according to claim 1, wherein the atmosphere containing no nitrogen atom is an atmosphere of an inert gas such as argon or a vacuum atmosphere.