JP2996644B2 - Method for manufacturing semiconductor device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for manufacturing a semiconductor device having a metal silicide whose oxide generation energy is higher in the positive direction than silicon oxide generation energy.

[0002]

2. Description of the Related Art For a silicon LSI transistor, a high melting point metal silicide is formed on a polysilicon gate and a source / drain region in order to reduce the resistance of the polysilicon gate and the diffusion layer resistance of the source / drain regions. A salicide process is being considered. Among them, the Co salicide process for forming CoSi ₂ is regarded as promising as a technology that can easily lower the resistance of a polysilicon gate or a diffusion layer having a small line width.

Hereinafter, a conventional Co salicide process will be described with reference to FIGS.
rti et al., Proceedings of IEEE VLSI Multilevel In
ternational Conference 1992, pp.267).

First, a transistor structure shown in FIG. 6A is formed. This transistor structure has a silicon substrate 1
(LOCOS) 3 formed on the surface of the substrate, source / drain regions 2 formed in the substrate 1, a gate oxide film 4 covering the channel region, and a gate electrode 5 formed on the gate oxide film 4. And an insulating sidewall spacer 6 formed on the side surface of the gate electrode 5.

Next, after the gate oxide film 4 and the natural oxide film on the source / drain regions 2 are removed, as shown in FIG. 6B, a cobalt (Co) film 7 and a titanium nitride film are formed by sputtering. A dry (TiN) film 8 is sequentially deposited.

Next, as shown in FIG. 6C, the substrate 1 is heated in an inert gas atmosphere such as nitrogen by using a rapid thermal annealing (RTA) technique.
A heat treatment is performed at 00 ° C. for about 60 seconds. Heating rate is 10
C / sec or more. By this heat treatment, the silicon region of the silicon substrate 1 and the gate electrode 5 react with the cobalt film 7 to form cobalt silicide (CoSi) 9.

An inert gas such as nitrogen is introduced into the lamp heating device, and the oxygen concentration in the atmosphere is kept low. However, about 5 ppm or more of oxygen remains in the apparatus. This corresponds to 5 × 10 ⁻⁶ atmospheres of oxygen at atmospheric pressure. T used for normal salicide
Although i is hardly affected by oxidation, Co is a metal which is very easily oxidized, so that even such a low level of oxygen is oxidized. Therefore, before the heat treatment for silicidation, it is necessary to cover the cobalt film 7 with the TiN film 8 functioning as an antioxidant film.

[0008] As shown in FIG.
Unreacted cobalt film and Ti with a mixture of H ₂ SO ₄ -H ₂ O ₂ of
The N film is removed by wet etching.

Finally, as shown in FIG. 6E, heat treatment is performed at 750 ° C. for about 30 seconds by rapid lamp heating at 10 ° C./second or more in an inert gas atmosphere such as nitrogen. Then C
The oSi film 9 further reacts with the silicon substrate 1 and the polysilicon of the gate electrode 5 to form a CoSi ₂ (cobalt disilicide) film 10. Since the specific resistance of this CoSi ₂ film is as low as about 16 μΩcm, the source / drain region 2
In addition, the resistance of the gate electrode 5 is reduced.

In the Co salicide process, the first rapid heat treatment is carried out at a relatively low temperature of 400 ° C. to 600 ° C. to form a CoSi film first.
_{This is because when the two} films are formed, CoSi ₂ goes up on the element isolation 3 and the insulating spacer 6, which may cause a short circuit between the source / drain region 2 and the gate electrode 5.

In recent years, by depositing a Ti film having a thickness of about 2 nm under a cobalt film, even if a rapid heat treatment at 700 ° C. or more is performed from the beginning, CoSi that does not go up
It has been reported that _two films can be formed (for example, S. Ogawa
et al., Extended Abstracts of International confe
rence on Solid State Devices and Materials, pp.19
5, 1993). Even in this case, in order to suppress oxidation of the surface of the cobalt film, the surface of the cobalt film is
It is considered necessary to cover with an N film or the like.

[0012]

Problems to be Solved by the Invention FIGS. 6 (a) to 6 (e)
In the technique described in (1), since a step of depositing a TiN film on a cobalt film is required, it is necessary to separately prepare a Ti target in a sputtering apparatus. Sputtering of a TiN film easily generates particles in a sputtering apparatus. When particles increase in the sputtering apparatus, the production yield of the semiconductor device tends to decrease.

A method has been proposed in which after depositing a cobalt film by a sputtering apparatus having a rapid thermal processing chamber, a semiconductor substrate is continuously moved to a rapid thermal processing chamber in a vacuum, and heat treatment is performed in the rapid thermal processing chamber. I have. (For example, K. Inoue et al., IEDM, pp. 445, 1
995). According to this method, C is deposited without depositing a TiN film.
An oSi ₂ film can be formed. However, this method has a low processing capability because the semiconductor substrate is moved in a vacuum and heat treatment is performed. Therefore, this method is not suitable for mass production.

SUMMARY OF THE INVENTION The present invention has been made in view of the above problems, and has as its object to provide a method of manufacturing a semiconductor device which enables silicidation without covering a metal film with an antioxidant film. It is in.

[0015]

A method of manufacturing a semiconductor device according to the present invention is a method of manufacturing a semiconductor device having a silicon region and a cobalt silicide film in contact with at least a part of the silicon region. Doping at least a portion of the silicon region to increase the boron concentration of the portion to 1 × 10 ¹⁵ cm ⁻³ or more; depositing a cobalt film on the surface of the silicon region; A first heat treatment step of causing a silicidation reaction in a portion in contact with the silicon region, thereby forming a cobalt silicide film, and a step of selectively removing an unreacted portion of the cobalt film that has not been silicided And causing a phase transition of the cobalt silicide film at a temperature higher than the temperature of the first heat treatment step. 2) a heat treatment step;
Is performed in a reducing atmosphere gas, and the temperature of the first heat treatment is about 400 ° C. or more and about 60 ° C.
0 ° C. or less.

[0016] The reducing atmosphere gas may be an inert gas containing hydrogen gas.

The reducing atmosphere gas may include an ammonia gas.

In one embodiment, a part of the silicon region is included in a single crystal silicon substrate, and another part of the silicon region is included in a wiring provided on the silicon substrate. ing.

The silicon region may be included in a single crystal silicon substrate.

The cobalt silicide film before the phase transition is made of CoSi, and after the phase transition, the cobalt silicide film is made of CoSi.
It may be changed to Si ₂ .

It is preferable that the volume fraction of the hydrogen gas with respect to the whole atmosphere gas is 4% or less.

The first heat treatment step is preferably performed using a lamp anneal.

[0023] The first heat treatment step is performed until the temperature reaches 1%.
It is preferable to raise the temperature of the cobalt film at a rate of 0 ° C./second or more.

Another method of manufacturing a semiconductor device according to the present invention is a method of manufacturing a semiconductor device having a metal silicide film whose oxide generation energy is higher in the positive direction than the oxide generation energy of silicon. Depositing a film of the metal on the surface of the region, a heat treatment step of causing a silicidation reaction between at least a portion of the metal and at least a portion of the silicon, thereby forming a silicide film of the metal; Wherein the heat treatment step is performed in a reducing atmosphere containing ammonia.

The heat treatment step is performed at a temperature of 400 ° C. to 700 ° C.
It is preferable to raise the temperature of the metal film at a rate of 10 ° C./sec or more up to a temperature between the two.

The method further includes a step of selectively removing an unreacted portion of the metal that has not been silicided, and another heat treatment step of causing a phase transition of the silicide film at a temperature higher than the temperature of the heat treatment step. It may be.

[0027] The metal may be cobalt.

Still another method of manufacturing a semiconductor device according to the present invention is a method of manufacturing a semiconductor device having a metal silicide film whose oxide generation energy is higher in the positive direction than silicon oxide generation energy, A substrate, a source region and a drain region formed in a silicon region on the surface of the substrate, a channel region sandwiched between the source region and the drain region on the surface of the silicon region, and formed on the channel region. Forming a transistor structure including a gate insulating film, a gate electrode formed on the gate insulating film, and an insulating sidewall covering a side surface of the gate electrode; Depositing a cobalt film so as to cover the region, and removing ammonia gas while exposing the cobalt film. Subjected to a heat treatment in an atmosphere containing,
Thereby, a step of forming a cobalt silicide film on the source region, the drain region and the gate electrode in a self-aligned manner is included.

The step of forming the cobalt silicide film is performed at a temperature of 10 ° C./400° C. to 700 ° C.
It is preferable to include a heat treatment step of raising the temperature of the cobalt film at a rate of at least seconds.

The step of forming the cobalt silicide film is performed at a temperature of 10 ° C./400° C. to 600 ° C.
A first heat treatment step of raising the temperature of the cobalt film at a rate of at least seconds, a step of selectively removing unreacted portions of the cobalt film that have not been silicided, and a step of lowering the temperature of the first heat treatment step. A second heat treatment step of causing a phase transition of the silicide film at a high temperature.

The doping of the source region and the drain region may be performed before the step of forming the cobalt silicide film.

The doping of the source region and the drain region may be performed after the step of forming the cobalt silicide film.

[0033]

Embodiments of the present invention will be described below with reference to the drawings. (First Embodiment) A first embodiment of a method for manufacturing a semiconductor device according to the present invention will be described with reference to FIGS.

First, according to a known manufacturing method, FIG.
The transistor structure shown in FIG. This transistor structure includes an element isolation (LOCOS) 3 formed on the surface of a silicon substrate 1, a source / drain region 2 formed in the substrate 1, a gate oxide film (SiO ₂ film) 4 covering a channel region, and A gate electrode 5 formed on the gate oxide film 4 and an insulating sidewall spacer 6 formed on a side surface of the gate electrode 5.

Instead of the silicon substrate 1, an insulating substrate supporting a silicon film may be used. In the future, when a highly integrated circuit is incorporated on an insulating substrate in a field such as a flat panel display, it is considered that the present invention is preferably applied.

The element isolation 3 is not limited to LOCOS,
Trench isolation may be used. Source / drain region 2
Preferably, after the gate electrode 5 and the insulating side wall spacer 6 are formed, impurity ions are implanted into the silicon substrate 1 using these as a mask, thereby forming the self-alignment with the gate electrode 5. The source / drain region 2 does not need to be formed from a single impurity diffusion layer, but may be formed from a combination of a plurality of impurity diffusion layers having several types of doping levels. For example, the source / drain regions 2 each have a relatively low concentration of an n ⁻ -type impurity diffusion layer (LDD).
And a relatively high concentration n ⁺ -type impurity diffusion layer. In this case, typically
The low-concentration impurity diffusion layer is formed by using an ion implantation technique before forming the insulating sidewall spacers 6.
Are formed in a self-aligned manner. The high-concentration impurity diffusion layer is formed after forming the insulating sidewall spacers 6.
It is formed in a region shifted outward from the gate electrode 5 by the insulating sidewall spacers 6 by using an ion implantation technique.

The gate electrode 5 according to the present embodiment is formed of polysilicon, and the line width of the gate electrode 5 is set to 0.1 in the present embodiment.
2 to 2.0 μm. This polysilicon is doped with an impurity such as arsenic.

Although a single transistor structure is shown in FIG. 1A for simplicity, a plurality of transistor structures are actually formed on one substrate. In this embodiment, at least a part of the plurality of transistor structures is a P-channel type, and the rest is an N-channel type. The source / drain region 2 of the P-channel transistor structure is doped with boron as a p-type impurity. Arsenic is doped in the source / drain region 2 of the N-channel transistor structure as an n-type impurity. The boron doping is preferably performed by implanting BF ₂ ions.

After forming the above transistor structure, FIG.
As shown in (b), a cobalt film 7 is deposited on the entire surface of the substrate 1. For depositing the cobalt film 7, it is preferable to use a sputtering method using a cobalt target. The thickness of the cobalt film 7 is, for example, about 5 nm to about 15 nm. A region of the surface of the silicon substrate 1 that contacts the cobalt film 7 is doped with p-type or n-type impurities at a high level. For example, in the source / drain region of a p-type transistor, boron having a dose of 3 × 10 ¹⁵ cm ⁻² is implanted, and in the source / drain region of an n-type transistor, arsenic having a dose of 2 × 10 ¹⁵ cm ⁻² is implanted. Have been. The cobalt film 7 is also in contact with polycrystalline silicon on the upper surface of the gate electrode 5. This polycrystalline silicon also has p
Type and / or n-type impurities are highly doped. For example, boron having a dose of 6 × 10 ¹⁵ cm ⁻² is implanted into the gate electrode 5 of the p-type transistor,
The gate electrode 5 of the type transistor has a dose of 7 × 10
Arsenic of ¹⁵ cm ^-2 is implanted.

Next, as shown in FIG.
In a nitrogen atmosphere containing hydrogen, for example, 30 ° C. /
A rapid lamp heating for 2 seconds is performed, and a heat treatment is performed at 500 ° C. for about 60 seconds. The heating rate may be 10 ° C./sec or more. By this heat treatment, a silicidation reaction proceeds in a portion where the silicon substrate 1 and the cobalt film 7 are in contact with each other and in a portion where the polysilicon of the gate electrode 5 is in contact with the cobalt film 7, thereby forming the CoSi film 9. You.
The portion of the cobalt film 7 that is in contact with the element isolation 3 and the insulating sidewall spacer 6 is not silicided,
It remains as an “unreacted portion”.

In this embodiment, in this heat treatment step, an inert gas to which hydrogen having a volume fraction of 4% is added is used as an atmosphere gas. As a result, the cobalt film 7 is
Even if not covered with an N film or the like, the oxidation of the cobalt film 7 can be effectively prevented.

After the heat treatment, as shown in FIG. 1D, unreacted portions of the cobalt film 7 are removed by wet etching using, for example, a mixed solution of H ₂ SO _{4 and} H ₂ O ₂ at 120 ° C. .

Finally, as shown in FIG. 1 (e), rapid lamp heating is performed at a rate of 10 ° C./sec or more in an inert gas atmosphere such as nitrogen, and heat treatment is performed at 750 ° C. for about 30 seconds. I do. In this second heat treatment, the CoSi film 9 is formed.
Further reacts with the silicon of the silicon substrate 1 and the gate electrode 5 to change into a CoSi ₂ (cobalt disilicide) film 10, and the sheet resistance further decreases.

FIGS. 2A and 2B respectively show C
The sheet resistance of a source / drain region formed by silicidizing the surface of the N ⁺ type impurity diffusion layer and the P ⁺ type impurity diffusion layer of the oSi ₂ film 10 is shown. CoSi ₂ film 10
Lamp heating equipment (lamp annealer) used for forming
The residual oxygen concentration is 5 to 20 ppm. When a rapid heat treatment is performed in a 100% nitrogen atmosphere as in the related art, N
^It can be seen that the sheet resistance of the P ⁺ -type impurity diffusion layer is higher than that of the ⁺ -type impurity diffusion layer, and the variation is larger. The reason will be described below.

First, reference is made to FIGS. 3A and 3B. FIGS. 3A and 3B both show the distribution in the depth direction of each element (nitrogen, oxygen, cobalt, and silicon) contained in the silicide film. The distribution was determined by XPS measurement. This measurement was performed after the first heat treatment step when forming a CoSi ₂ film by two-step heat treatment. FIG. 3A shows the results when heat treatment was performed in a mixed gas of hydrogen gas and nitrogen gas as an atmosphere, and FIG. 3B shows the results when heat treatment was performed in a nitrogen gas atmosphere. ing. The conditions for the heat treatment are the same as the conditions for the first rapid lamp heating described above.

When hydrogen gas is not contained in the atmosphere,
Oxygen is distributed from the surface of the cobalt silicide to a deep position, and the density of cobalt monotonously decreases from the deep position toward the surface. On the other hand, when hydrogen gas is contained in the atmosphere, the distribution of oxygen is limited to the vicinity of the surface of the silicide, and the density of cobalt also changes sharply near the surface. This means the following.

First, when hydrogen gas is not added to the atmospheric gas, the oxidation of cobalt proceeds sufficiently even at a relatively low temperature of about 60 seconds at 500 ° C. for a short time. Second, the addition of hydrogen gas sufficiently suppresses oxide formation on the cobalt surface even at a relatively low temperature of about 60 seconds at a temperature of 500 ° C. for a short time. Third,
This means that the oxidation suppressing effect is exhibited only by adding a slight amount of hydrogen gas (volume fraction of 4%) to the atmosphere gas.

Next, reference is made to FIGS. 4A and 4B. FIG. 4 (a) schematically shows how the oxidation of the cobalt surface being silicided proceeds in nitrogen gas, and FIG. 4 (b) shows the oxidation of the cobalt surface being silicided. It shows schematically how the process proceeds in nitrogen gas to which hydrogen gas has been added. The silicidation reaction occurring on the lower surface of the cobalt film competes with the oxidation reaction occurring on the upper surface of the cobalt film. The underlying silicon region is doped with boron (boron concentration: 1 × 1
0 ¹⁵ cm ⁻³ ), it is known that the rate of the silicidation reaction decreases. Therefore, on the boron-doped P ⁺ -type impurity diffusion region, surface oxidation of the cobalt film is superior to silicidation. However, when hydrogen is added to the atmosphere gas, the rate of the oxidation reaction is reduced, so that the influence of the oxidation on the sheet resistance is reduced.

As described above, according to this embodiment, even if the silicidation of the cobalt film is delayed by boron (B) doped in the P ⁺ -type source / drain regions, the surface oxidation of the cobalt film is suppressed.

In the case where hydrogen is not added, when the width of the N ⁺ type source / drain region is 1 μm or less, the sheet resistance increases and the variation is large. This is also caused by surface oxidation of the cobalt film. By adding hydrogen, the sheet resistance is kept low and the variation is small.

As described above, 4% by weight of H
_{When 2} is added, a result equivalent to that obtained when a TiN film is deposited on a cobalt film to prevent oxidation is obtained. In particular, the present invention is effective in performing silicidation between boron-doped silicon and a cobalt film.

Although nitrogen is used as the inert gas in this embodiment, another gas such as Ar may be used. In addition, instead of performing the heat treatment for silicidation in almost two stages as in the present embodiment, CoSi is performed only once by heat treatment.
_Two films may be formed. In the present embodiment, the hydrogen gas is added to the atmosphere gas only at the time of the first heat treatment, but the hydrogen gas may be added to the atmosphere gas also at the time of the second heat treatment.

(Second Embodiment) FIGS. 5A to 5E
A second embodiment of the method for manufacturing a semiconductor device according to the present invention will be described with reference to FIG.

First, according to a known manufacturing method, FIG.
The transistor structure shown in FIG. This transistor structure includes an element isolation (LOCOS) 3 formed on the surface of a silicon substrate 1, a source / drain region 2 formed in the substrate 1, a gate oxide film (SiO ₂ film) 4 covering a channel region, and A gate electrode 5 formed on the gate oxide film 4 and an insulating sidewall spacer 6 formed on a side surface of the gate electrode 5. This transistor structure may be the same as the structure in the above-described embodiment described with reference to FIG. The manufacturing method is the same as the method described above.

Next, as shown in FIG. 5B, a cobalt film 7 is deposited on the entire surface of the substrate 1 by a sputtering method using a cobalt target. Also in the present embodiment, the cobalt film 7
Is preferably about 5 nm to about 15 nm.

Next, as shown in FIG.
That is, 1% in a nitrogen atmosphere containing 1% ammonia gas.
The heat treatment is performed at 500 ° C. for about 60 seconds by rapid lamp heating at 0 ° C./sec or more, for example, at 30 ° C./sec. At this time, the polysilicon of the source / drain region 2 and the gate electrode 5 react with the cobalt film 7 to form CoSi9. At this time,
Ammonia (NH ₄ ) gas is thermally decomposed, active hydrogen is generated, and oxygen gas, water or other impurity gas which may oxidize the cobalt film is reduced to the atmosphere, and the cobalt film 7 is converted to Ti.
Oxidation of the cobalt film 7 can be prevented even if it is not covered with the N film or the like or is exposed. A preferable ratio of ammonia gas is a volume fraction of about 0.5% of the whole.
~ 100%.

Next, as shown in FIG.
Unreacted portions of the cobalt film are removed by wet etching using a mixed solution of H ₂ SO ₄ -H ₂ O ₂ at 20 ° C.

Next, as shown in FIG.
Perform rapid lamp heating at 10 ° C / sec or more in a nitrogen atmosphere,
Heat treatment is performed at 750 ° C. for about 30 seconds. Thereby, C
The oSi film 9 undergoes a phase transition to the CoSi ₂ film 10.

According to the present embodiment, since 1% ammonia gas is added to the atmosphere gas in the heat treatment step for silicidation, the sheet resistance is low and stable up to a minimum line width of 0.1 μm. Further, there is no difference in sheet resistance between the P ⁺ type source / drain region diffusion layer and the N ⁺ type source / drain region impurity diffusion layer.

By using ammonia gas instead of hydrogen gas, there is no danger of explosion and the cost required for equipment safety measures can be reduced, so that the unit cost of the manufacturing process can be reduced.

In this embodiment, nitrogen is used as the atmospheric gas of ammonia, but other gases such as Ar may be used. Although ammonia was added only at the time of the first heat treatment, ammonia gas may be added to the atmosphere gas at the time of the second annealing for forming the CoSi ₂ film.

Although the embodiment has been described by taking Co as an example of the metal material, the present invention provides that the oxide generation energy is greater in the positive direction than the oxide formation energy of Si,
It is also effective for forming a silicide film of a metal such as Ta or Hf, which is less susceptible to oxidation.

In this embodiment, the doping of the source region and the drain region is performed before the silicidation. However, after the silicidation, impurity ions may be implanted into the silicide film to use the silicide as a dopant source. This makes it possible to form a shallower junction than implanting impurity ions into a silicon substrate before silicidation.

[0064]

According to the method of manufacturing a semiconductor device of the present invention, cobalt silicide can be formed without covering the cobalt film with an antioxidant film such as TiN.

According to another method of manufacturing a semiconductor device of the present invention, when forming a metal silicide whose oxide generation energy is higher in the positive direction than the oxide formation energy of Si, an antioxidant film such as TiN is formed. Can form a silicide of the metal without covering the metal.

[Brief description of the drawings]

FIGS. 1A to 1E are process cross-sectional views for describing a first embodiment of a method for manufacturing a semiconductor device according to the present invention.

FIGS. 2A and 2B are graphs showing measurement results of a sheet resistance of the semiconductor device according to the first embodiment.

3 (a) and 3 (b) are graphs each showing the distribution in the depth direction of each element (nitrogen, oxygen, cobalt and silicon), and FIG. 3 (a) is a graph showing hydrogen gas and nitrogen gas. (B) shows the results when the heat treatment was performed in an atmosphere of a gas mixture of the above and (b).

4A is a cross-sectional view schematically showing how oxidation of a cobalt surface being silicided proceeds in a nitrogen gas, and FIG. 4B is a cross-sectional view showing a cobalt being silicided. It is sectional drawing which shows typically how the oxidation of a surface progresses in the nitrogen gas to which the hydrogen gas was added.

FIGS. 5A to 5E are process cross-sectional views for explaining a second embodiment of the method for manufacturing a semiconductor device according to the present invention.

FIGS. 6A to 6E are process cross-sectional views illustrating a conventional example of a method for manufacturing a semiconductor device.

[Explanation of symbols]

Reference Signs List 1 silicon substrate 2 source / drain region 3 element isolation 4 gate oxide film 5 gate electrode 6 insulating spacer 7 cobalt film 8 TiN film 9 CoSi 10 CoSi ₂

──────────────────────────────────────────────────続 き Continuation of the front page (72) Inventor Tatsuo Sugiyama 1-1, Sachimachi, Takatsuki City, Osaka Prefecture Inside Matsushita Electronics Corporation (56) References JP-A-9-260649 (JP, A) JP-A Heisei 8-274047 (JP, A) (58) Fields investigated (Int. Cl. ⁷ , DB name) H01L 21/28 301 H01L 21/336 H01L 29/78

Claims (18)

(57) [Claims] 1. A method of manufacturing a semiconductor device, comprising: a silicon region; and a cobalt silicide film in contact with at least a part of the silicon region, wherein boron is doped into at least a part of the silicon region. A step of increasing the boron concentration to 1 × 10 ¹⁵ cm ⁻³ or more; a step of depositing a cobalt film on the surface of the silicon region; and a step of silicidation in a portion where the cobalt film and the silicon region are in contact with each other. Causing a first heat treatment step to form a cobalt silicide film, thereby selectively removing unreacted portions of the cobalt film that have not been silicided; and a temperature higher than the temperature of the first heat treatment step. And a second heat treatment step for causing a phase transition of the cobalt silicide film. The method is performed in a reducing atmosphere gas, wherein the temperature of the first heat treatment step is about 400 ° C. or more and about 600 ° C. or less. 2. The method according to claim 1, wherein said reducing atmosphere gas is an inert gas containing hydrogen gas. 3. The method according to claim 1, wherein the reducing atmosphere gas includes an ammonia gas. 4. The method according to claim 1, wherein the silicon region is included in a single crystal silicon substrate. 5. The method according to claim 1, wherein a part of the silicon region is included in a single crystal silicon substrate, and another part of the silicon region is included in a wiring provided on the silicon substrate. Item 4. The method for manufacturing a semiconductor device according to any one of Items 1 to 3. 6. The cobalt silicide film before the phase transition is made of CoSi, and the cobalt silicide film is formed after the phase transition.
The method of manufacturing a semiconductor device according to claim 1 which changes the OSI _2. 7. The method of manufacturing a semiconductor device according to claim 2, wherein a volume fraction of the hydrogen gas with respect to the whole atmosphere gas is 4% or less. 8. The method according to claim 1, wherein the first heat treatment is performed using a lamp anneal. 9. The method according to claim 1, wherein in the first heat treatment step, the temperature of the cobalt film is increased at a rate of 10 ° C./sec or more to the temperature. 10. A method of manufacturing a semiconductor device comprising a metal silicide film having an oxide generation energy higher than an oxide generation energy of silicon in a positive direction, wherein the metal film is deposited on a surface of a silicon region. Performing a silicidation reaction between at least a portion of the metal and at least a portion of the silicon, thereby forming a silicide film of the metal,
A method of manufacturing a semiconductor device, wherein the heat treatment step is performed in a reducing atmosphere containing ammonia. 11. The heat treatment step is performed from 400 ° C. to 70 ° C.
The method of manufacturing a semiconductor device according to claim 9, wherein the temperature of the metal film is increased at a rate of 10 ° C./sec or more to a temperature between 0 ° C. 12. A step of selectively removing an unreacted portion of the metal that has not been silicided, and another heat treatment step of causing a phase transition of the silicide film at a temperature higher than the temperature of the heat treatment step. The method for manufacturing a semiconductor device according to claim 9, further comprising: 13. The method of claim 10, wherein said metal is cobalt.
Or a method for manufacturing a semiconductor device according to item 11. 14. A method of manufacturing a semiconductor device comprising a metal silicide film whose oxide generation energy is higher than the oxide generation energy of silicon in a positive direction, comprising: a substrate; and a silicon region on a surface of the substrate. A source region and a drain region formed, a channel region sandwiched between the source region and the drain region on the surface of the silicon region, a gate insulating film formed on the channel region, and Forming a transistor structure having a gate electrode formed on the substrate and an insulating sidewall covering a side surface of the gate electrode; and depositing a cobalt film so as to cover an exposed silicon region of the transistor structure. And performing a heat treatment in an atmosphere containing ammonia gas while exposing the cobalt film. Therefore, a method of manufacturing a semiconductor device including a step of forming a cobalt silicide film in a self-aligning manner on the source region, the drain region and the gate electrode. 15. The step of forming the cobalt silicide film is performed at a temperature between 400 ° C. and 700 ° C.
The method of manufacturing a semiconductor device according to claim 14, further comprising a heat treatment step of raising the temperature of the cobalt film at a rate of not less than ° C./sec. 16. The step of forming the cobalt silicide film includes: a first heat treatment step of raising the temperature of the cobalt film to a certain temperature between 400 ° C. and 600 ° C. at a rate of 10 ° C./sec or more; A step of selectively removing unreacted portions of the film that have not been silicided; a second heat treatment step of causing a phase transition of the silicide film at a temperature higher than the temperature of the first heat treatment step;
The method for manufacturing a semiconductor device according to claim 14, comprising: 17. The method according to claim 14, wherein doping of the source region and the drain region is performed before the step of forming the cobalt silicide film. 18. The method according to claim 14, wherein doping of the source region and the drain region is performed after the step of forming the cobalt silicide film.