JPH05251384A - Semiconductor device and manufacture thereof - Google Patents

Abstract

PURPOSE:To provide a semiconductor which is capable of preventing a drop in the reliability of this semiconductor device caused by disconnection in a connection hole and an increase in contact resistance. CONSTITUTION:This semiconductor device is formed on a semiconductor substrate 11 where the device comprises an insulation film 14 having a contact hole 15 on an impurity diffusion layer 13 formed on this semiconductor substrate 11, a reaction preventative film 16 formed on the sides and the bottom of the contact hole 15 and an Ni3Si film 17 which fills in the contact hole 15.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a semiconductor device and a method of manufacturing the same, and more particularly to improvement of a connection layer embedded in a connection hole.

[0002]

2. Description of the Related Art FIG. 8 shows a sectional view of the shape of a contact hole obtained by a conventional manufacturing method. This will be described according to the manufacturing process. First, the insulating film 92 for element isolation is formed on the silicon substrate 91.

Next, after forming an impurity diffusion layer 93 in the element forming region, an insulating film 94 is deposited on the entire surface. Then, a contact hole 95 is formed by a photolithography process and an etching process.

Finally, after removing the photoresist used in the above process, an aluminum film 96 is deposited on the entire surface by sputtering and the inside of the contact hole 95 is covered with the aluminum film 96.

However, this type of method has a problem in that the aluminum film 96a on the side of the contact hole 95 becomes very thin, which easily causes disconnection and is not suitable for fine elements. Further, the overhang shape of the aluminum film 96 on the contact hole 95 is also a problem. That is, such an overhang portion causes a void in the insulating film at the time of depositing the insulating film in a later step, and causes a reliability problem.

Therefore, in order to solve such a problem, a method of burying a conductive material in the contact hole has been proposed. Specifically, the contact hole is made of a metal such as aluminum or tungsten by using the selective CVD method.
There is a method in which the contact hole is filled with polysilicon after the entire surface of the polysilicon film is etched back after filling polysilicon or depositing polysilicon by using the LPCVD method.

However, when a metal is used, it is difficult to control the interface between the semiconductor substrate and the metal, and the reaction between the semiconductor substrate and the metal lowers the reliability. Moreover, there is also a problem that it is difficult to obtain a good embedded shape because metal is difficult to process. Further, the selective CVD method has a problem that it is difficult to simultaneously embed contact holes having different depths. Also,
When polysilicon is used, a good embedded shape can be obtained, but there is a problem that the electric resistance becomes high.

[0008]

As described above, in the prior art, in order to prevent disconnection in the contact hole, which tends to occur with the miniaturization of the element, the contact hole is embedded with a conductive material. However, good shape and low resistance could not be satisfied at the same time.

The present invention has been made in view of the above circumstances, and an object thereof is to provide a semiconductor device and a semiconductor device which can prevent a decrease in reliability due to a disconnection or the like in a contact hole and an increase in contact resistance. It is intended to provide a manufacturing method thereof.

[0010]

The essence of the present invention resides in that the contact hole is filled with a silicide film in which the metal composition ratio is larger than that of silicon.

In other words, in order to achieve the above object, the semiconductor device of the present invention includes an insulating film formed on a semiconductor substrate and having a connection hole on a predetermined element or wiring provided on the semiconductor substrate, The present invention is characterized by comprising a reaction preventive film formed at least at the bottom of the contact hole, and a silicide film filling the contact hole and having a metal composition ratio higher than that of silicon.

Another semiconductor device of the present invention is an insulating film which is formed on a semiconductor substrate and has a plurality of connection holes of different depths on a predetermined element or wiring provided on the semiconductor substrate. A reaction prevention film formed at least at the bottom of the connection hole; and a silicide film that fills the connection hole and has a larger metal composition ratio as the connection hole is shallower, and at least one of the silicide films has a metal composition. It is characterized in that the ratio is greater than that of silicon.

The method of manufacturing a semiconductor device according to the present invention is
A step of forming an insulating film having a connection hole on a semiconductor substrate on which an element or a wiring is formed, a step of forming a reaction preventing film on at least the bottom of the connection hole, and a step of embedding silicon in the connection hole, After depositing a metal film on the entire surface, a step of reacting the metal film with the silicon by heat treatment at a predetermined temperature to form a silicide film in which the metal composition ratio is larger than that of silicon is formed. Is characterized by.

[0014]

Since the semiconductor device of the present invention is provided with the reaction preventive film, when the silicide film is filled in the connection hole, an unnecessary reaction occurs in the semiconductor substrate or a problem occurs. Can be prevented. In addition, since the metal composition ratio of the silicide film is larger than that of silicon, the silicide film is more stable than the case where the silicon composition ratio is larger than that of metal. It can be prevented from changing. Therefore, a semiconductor device having predetermined element characteristics can be obtained. Further, a silicide film in which the composition ratio of silicon is larger than that of metal can be reliably formed by, for example, filling the connection hole with silicon, depositing a sufficient amount of the metal film, and performing heat treatment. Therefore, it is possible to easily fill all the contact holes with the silicide film having the same composition, and obtain a semiconductor device with less variation in element characteristics.

In another semiconductor device of the present invention, the shallower the contact hole, the larger the metal composition ratio of the silicide film. Such a silicide film has an advantage that it can be easily formed by burying silicon in the connection hole, then depositing a metal film on the entire surface and performing heat treatment. Further, since the metal has a silicide film whose composition ratio is higher than that of silicon, a semiconductor device having excellent element characteristics can be obtained as compared with the case where the composition ratio of silicon is higher than that of metal for all the silicide films. Be done.

According to the method of manufacturing a semiconductor device of the present invention,
For example, when a low temperature of 450 ° C. or lower is selected as the predetermined temperature and silicon and nickel are reacted with each other, nickel silicide having a low specific resistance is formed.
Further, since the reaction temperature is low, even if the wirings are made of a wiring material having a low melting point such as Al, the wirings will be damaged.
There is no problem of giving up. If polycrystalline silicon is used as the above-mentioned silicon, the workability is superior to that of metal, so that a good embedded shape can be obtained and the reliability can be prevented from lowering due to disconnection or the like.

[0017]

Embodiments will be described below with reference to the drawings.

FIG. 1 is a sectional view of the shape of a contact hole according to the first embodiment of the present invention. On the surface of the semiconductor substrate 11, an impurity diffusion layer 13 such as a MOS transistor, which is separated from other elements by an insulating film 12, is formed. The semiconductor substrate 11 is covered with an insulating film 14 in which a contact hole 15 is formed on the impurity diffusion layer 13. A reaction preventing film 16 made of titanium nitride is formed on the side and bottom of the contact hole 15. Then, the contact hole 15 is filled with the Ni ₃ Si film 17 which is a silicide film, and has a good contact filling shape.

According to this embodiment, the contact hole 15
Since the reaction preventive film 16 is provided inside the Ni ₃ Si film 1
It is possible to prevent a problem that an unnecessary reaction occurs in the semiconductor substrate 11 or the semiconductor substrate 11 is damaged during the formation of 7. Further, since the Ni ₃ Si film 17 lowers the resistance, a low contact resistance can be obtained.

Although Ni ₃ is used as the material of the silicide film in this embodiment, instead of Cr ₃ Si,
Co ₃ Si, Fe ₃ Si, Hf ₃ Si, Ir ₃ Si, M
o ₃ Si, pd ₃ Si, pt ₃ Si, Ti ₃ Si, V ₃
A material having a composition of M ₃ Si (M is a metal element) such as Si or W ₃ Si may be used. Further, instead of a material having a composition of M ₃ Si, Rh ₂ Si, Ta ₂ Si, Ti ₂ S
A material having a composition of M ₂ Si such as i and SiZr ₂ may be used.

FIG. 2 is a sectional view showing the shape of a contact hole according to the second embodiment of the present invention. This will be described according to the manufacturing process. First, the semiconductor substrate 21 is separated by the insulating film 22, and then n ⁺ A type impurity diffusion layer 23 and a polysilicon film 24 having a predetermined shape to be a wiring are formed.

Next, after depositing an insulating film 25 on the entire surface, the insulating film 35 is etched to have a depth of 0.4 μm and an opening area of 0.6 μm × 0 on the polysilicon film 24 and the impurity diffusion layer 23, respectively. 6 μm contact hole 28a,
A contact hole 28b having a depth of 1 μm and an opening area of 0.6 μm × 0.6 μm is formed.

Next, the inner surfaces of the contact holes 28a and 28b are covered. A reaction prevention film 27 made of a titanium nitride film is deposited on the front surface. Then, after depositing a polysilicon film on the entire surface, the polysilicon film is left only on the contact holes 28a and 28b by etching back.

Next, a thickness of 0.5 is obtained by using a sputtering method.
After depositing Ni of Ni on the entire surface, in an argon atmosphere,
Heat treatment is performed at 600 ° C. for about 1 minute. As a result, in the deep contact hole 28b, the NiSi film 30 is formed by the reaction between the polysilicon film and Ni. On the other hand, in the shallow contact hole 28a, the Ni ₃ Si film 31 is formed by the reaction between the polysilicon film and Ni. here,
The Ni ₃ Si film 30 is not formed in the deep contact hole 28b because Ni is insufficient. Also, N
The specific resistances of iSi and Ni ₃ Si are 14 μΩc respectively.
m, 93 μΩcm, but since the Ni ₃ Si film 30 is embedded in the shallow contact 28a, there is no practical problem.

In this embodiment, the heat treatment at 600 ° C. was performed, but the same effect can be obtained at 800 ° C. or lower. The heat treatment temperature is set to 800 ° C. or lower because the reaction preventive film 27 does not perform its function at a temperature higher than 800 ° C., for example, Ni in the NiSi film 30 and the Ni ₃ Si film 31 penetrates the reaction preventive film 27. And reacts with the semiconductor substrate 21.

As described above, according to this embodiment, the contact holes 28a and 28b are formed of the Ni ₃ Si film 3 respectively.
Since it is filled with the 1, Ni ₃ Si film 30, the disconnection of the silicide film is eliminated. Furthermore, the Ni ₃ Si film 31, the Ni ₃
Since the Si film 30 has a lower resistance than the polysilicon film, it is possible to realize a low resistance nickel silicide region which is connected to the impurity diffusion 23 through the reaction preventing film 27. In the method of this embodiment, it is not possible to fill all the contact holes with the Ni ₃ Si film, but since a plurality of contact holes are simultaneously filled with the silicide film, the individual contact holes are not filled. The step of filling the contact holes is simplified as compared with the case of filling the Ni ₃ Si film in separate steps.

FIG. 3 is a sectional view of the shape of a contact hole according to the third embodiment of the present invention. The parts corresponding to those in FIG. 2 are designated by the same reference numerals as those in FIG. 2, and detailed description thereof will be omitted.

This embodiment differs from the second embodiment in that
This is because a Ni film having a thickness of 0.8 μm was deposited on the entire surface.
As a result, sufficient Ni is supplied to the deep contact hole 28b, and Ni ₃ Si is also supplied to the deep contact hole 28b.
It can be filled with a membrane 31. Next, the advantage of being able to form a silicide film of the same composition regardless of the depth of the contact hole as in this embodiment will be described. In general, in the silicidation reaction, the composition of the silicide film changes depending on the ratio of the amount of reacting silicon to the amount of metal and the reaction temperature.

When the composition of the silicide film changes, various properties thereof, for example, crystalline properties such as crystal structure and lattice constant, thermal properties such as melting point and expansion coefficient, and electrical properties such as specific resistance and Hall coefficient. Changes in properties and chemical properties such as chemical resistance and corrosion resistance.

If these properties change due to slight differences in the manufacturing process, a stable semiconductor device cannot be realized. Therefore, it is important to control the ratio of the amount of silicon to the amount of metal and the reaction temperature. By the way, although the reaction temperature can be controlled relatively easily, it is difficult to keep the ratio of the amount of silicon and the amount of metal constant. This is for the following reasons.

The amount of metal is not so difficult because the film thickness can be easily controlled by using a sputtering method or the like. However, the amount of silicon in the contact hole is determined by the volume of the contact hole, unlike the case where almost infinite amount of silicon is present as in the case of silicidation of a normal silicon substrate.

The volume of the contact hole is determined by the opening area of the contact hole and the depth of the contact hole. In one LSI, the opening areas and depths of the contact holes are not always the same. This makes it difficult to maintain a predetermined ratio between the amount of silicon and the amount of metal. Moreover, in the case of nickel silicide, as the amount of nickel increases, NiSi ₂ , NiSi, Ni ₃ S
The composition may be i ₂ , Ni ₂ Si, Ni ₅ Si ₂ , Ni ₃ Si, or the like. The crystal structure changes with each composition, and the physical properties also change.

Therefore, as in this embodiment, thick Ni is used.
If a film is deposited to form a Ni ₃ Si film 31, Ni ₃ S
i is stable, so Ni ₂ Si, Ni ₃ S
Since the composition such as i ₂ does not change, it is possible to obtain a stable device with little variation in characteristics.

In this embodiment, a deep contact hole is used.
28b is Ni ₃ Si, which has a larger specific resistance than the NiSi film.
Although it is filled with the film 31, if the depth of the deep contact hole 28b of this embodiment is about the depth of the shallow contact hole of the previous embodiment, there is no problem with the contact resistance.

In the present embodiment, the case where the number of contact holes is two has been described. However, even if the number of contact holes is larger than that, all contact holes have the same composition, that is, a silicide film, that is, a Ni ₃ Si film. Can be filled with. Furthermore, even when the contact hole opening areas are different, a sufficient amount of N
If i can be supplied to the polysilicon film of each contact hole, all contact holes can be filled with the Ni ₃ Si film. 4A to 4D are process cross-sectional views for explaining a connection method according to a fourth embodiment of the present invention.

First, as shown in FIG. 4A, a thickness of 0.6 is formed on a Si substrate 41 on which a desired element (not shown) is formed.
A μm insulating film 42 is deposited by the CVD method. Next, after forming a connection hole having a depth of 0.5 μm on the element, a reaction preventing film 43 having a two-layer structure of a TiN film having a thickness of 100 nm and a Ti film having a thickness of 20 nm is formed on the entire surface. Note that Ti
The N film is the upper layer film and the Ti film is the lower layer film.

Next, as shown in FIG. 4B, a polysilicon film 44 to be a connecting layer having a thickness of about 1.0 μm is formed on the entire surface.
After being deposited by the CVD method at a temperature of about 00 ° C., the entire surface of the polysilicon film 44 is etched by using reactive ion etching so that the polysilicon film 44 is formed only in the connection holes.
To leave. Since polysilicon has better workability than metal, a good embedded shape can be obtained, and a decrease in reliability due to disconnection or the like can be prevented.

Next, the Si substrate 41 is loaded into a vacuum device,
The Si substrate 41 is irradiated with an inert gas such as Ar. As a result, the oxygen and oxide layers on the surface of the polysilicon film 44, which hinder the silicide reaction, are removed. Next, as shown in FIG. 4C, a Ni film 45 having a thickness of 0.6 μm is deposited on the entire surface by sputtering Ni in the same vacuum.

Next, as shown in FIG. 4D, the silicide reaction, that is, the Ni film 45 and the polysilicon film 44 are reacted by annealing at 450 ° C. for 3 hours in an Ar atmosphere, and the polysilicon film 44. To the Ni ₂ Si film 46.

Here, the reason why the silicidation reaction is performed at a low temperature of 450 ° C. is to form nickel silicide having a small specific resistance. Ni ₂ Si has a specific resistance of about 20 μΩcm, and other nickel silicide (for example, N ₂ Si).
i ₃ Si has a smaller specific resistance than about 80 μΩcm). Next, as shown in FIG. 4E, an unreacted Ni film 45 is formed.
Is removed by a solution containing H ₂ O ₂ and HCl.
Finally, a wiring material such as Al is deposited on the entire surface and then patterned to form the wiring 47 on the Ni ₂ Si film 47.

Thus, according to this embodiment, since the polysilicon film 44 is used, a good embedded shape can be obtained,
Since it is possible to prevent a decrease in reliability due to voids, overhangs, disconnections, and the like, and because the silicide reaction is performed at a low temperature, it is possible to form a Ni ₂ Si film 46 having a small specific resistance among nickel silicide, and to reduce contact resistance. Can be achieved.

Further, since the silicidation reaction is carried out at a low temperature, there is a concern that the reaction speed may be slowed down. In the present embodiment, however, the oxygen and oxide layers on the surface of the polysilicon film 44 which hinder the silicidation reaction are removed. Since it has been removed, there is no practical problem in that respect. In this embodiment, 4
Although the Ni ₂ Si film 47 was formed at 50 ° C., it can be formed at a lower temperature. 5A to 5D are process cross-sectional views for explaining a connection method according to a fifth embodiment of the present invention. The present embodiment differs from the previous embodiments in the method of removing impurities that interfere with the silicide reaction.

First, as shown in FIG. 5A, an insulating film 52 is formed on a Si substrate 51 on which desired elements (not shown) are formed.
After forming, the connection hole, the reaction preventive film (TiN / Ti laminated film) 53 and the polysilicon film 54 are formed. The process up to this point is the same as in the fourth embodiment. Next, instead of irradiating the surface of the polysilicon film 54 with Ar as in the previous embodiment, the Ni film is deposited and then the impurities are removed.

That is, as shown in FIG. 5B, after the Ni film 55 having a thickness of 0.6 μm is deposited on the entire surface, the acceleration voltage 30 is applied.
Ar ²⁺ is ion-implanted under the conditions of 0 keV and a dose of 1 × 10 ¹⁵ cm ^-2 . By this ion implantation, the Ni film 55
Impurities such as oxygen and oxide existing between the polysilicon film 54 and the polysilicon film 54 are dispersed in the polysilicon film 54, and the adverse effects of the impurities that hinder the silicide reaction can be removed as in the previous embodiment.

Next, as shown in FIG. 5C, the polysilicon film 54 and the Ni film 55 are reacted by annealing at 450 ° C. for 3 hours in an Ar atmosphere, and the Ni ₂ Si film 5 is formed.
6 is formed. Finally, as shown in FIG. 5D, the wiring 57 is formed after removing the unreacted Ni film 55. Even with the method described above, it is possible to prevent the reliability of the wiring from decreasing and the contact resistance from increasing, as in the previous embodiment. Figure 6
It is process sectional drawing for demonstrating the connection method which concerns on the 6th Example of this invention.

First, as shown in FIG. 6A, the desired element was formed by the same method as in the fourth embodiment.
After forming the insulating film 62 on the i substrate 61 and opening the connection hole, a reaction preventing film (TiN / Ti film) 63 is formed. Next, a 0.2 μm thick Ni film 64 is formed on the reaction preventing film 63 by a sputtering method or a CVD method.

Next, as shown in FIG. 6B, a 0.7 μm-thick polysilicon film 65 is deposited on the entire surface, and then the entire surface of the polysilicon film 65 is etched by reactive ion etching to form the inside of the connection hole. The polysilicon film 65 is left alone.

Next, as shown in FIG. 6C, once again,
The Ni film 66 is deposited on the entire surface by about 0.5 μm by the sputtering method or the CVD method. As a result, the entire surface of the polysilicon film 65 is covered with the Ni films 64 and 66.

Next, as shown in FIG. 6D, similar to the fifth embodiment, the Ni films 64 and 66 and the polysilicon film 65 are reacted by annealing at a low temperature of 450 ° C. in an Ar atmosphere. Then, a Ni ₂ Si film 67 having a low specific resistance among nickel silicide is formed. In the case of this embodiment, Ni
The contact area between the polysilicon film and the Ni film is increased by the amount of the film 64 as compared with the previous embodiment. Therefore, there is no concern that the reaction rate will decrease even if the impurities that hinder the silicide reaction are not removed.

Finally, as shown in FIG. 6E, the unreacted Ni films 64 and 66 are removed by wet etching using a solution containing H ₂ O ₂ and HCl, as in the previous embodiment. After that, the wiring 68 is formed on the Ni ₂ Si film 67. Even with the method described above, similarly to the previous embodiment, it is possible to prevent a decrease in the reliability of the wiring without increasing the contact resistance. FIG. 7 is a cross-sectional view of a via hole according to a seventh embodiment of the present invention.

In the above embodiment, the case of the contact hole which is a connection hole between the element formed on the substrate and the wiring has been described, but the present invention can be applied to the via hole which is a connection hole between the wirings.

That is, as shown in FIG. 7, first, the insulating film 72 is formed on the Si substrate 71, and then the first Al wiring 73 is formed on the insulating film 72. Next, the interlayer insulating film 7
4 is formed, a via hole is opened in this interlayer insulating film 74, and then a reaction preventing film 75 is formed. And
Using the same method as in the above embodiment, the inside of the via hole is Ni
_{A second} Al wiring 77 that is filled with the ₂ Si film 76 and is connected to the first Al wiring 72 through the Ni ₂ Si film 76 is formed. Since the Ni ₂ Si film 76 is formed at a low temperature, the low melting point Al wiring 73 is not damaged.

Thus, according to this embodiment, since the wirings can be connected in the low temperature process, even if the wirings are made of a wiring material having a low melting point such as Al, no damage is given to the wirings. In addition, the same effect as that of the previous embodiment can be obtained.

Although Ni ₂ Si is used as the nickel silicide in the fourth to sixth embodiments, Ni ₃ Si may be used instead. Since Ni ₃ Si is formed at a temperature higher than 400 ° C., the reaction is more stable than Ni ₂ Si. Also, because it takes less time to form,
It is advantageous in terms of mass productivity as compared with Ni ₂ Si. Further, since the volume expansion during the reaction is small, it is advantageous for flattening the contact surface and reducing the stress on the contact portion.

The present invention is not limited to the above embodiment. For example, in the above embodiment, the case of the nickel silicide film has been described, but other silicide films, for example, molybdenum silicide film, tungsten silicide film, cobalt silicide film, titanium silicide film, vanadium silicide film, palladium silicide film, platinum silicide film. Even in the case of a film, if the composition ratio of the metal is increased, for example, M ₃ Si (M is a metal element) can achieve the same effect.

In the above embodiment, the side wall and bottom of the contact hole are covered with the reaction preventive film, but only the bottom may be covered with the reaction preventive film. Further, a reaction preventive film other than the TiN / Ti film may be used.

Further, in the first embodiment, the embedding of the contact hole in the impurity diffusion layer such as the MOS transistor has been described, but the present invention can be applied to the embedding of the contact hole in the element such as the bipolar. In addition, various modifications can be made without departing from the scope of the present invention.

[0058]

As described above in detail, according to the present invention, since the connection hole is filled with a stable silicide film having a good shape, it is possible to prevent variations in device characteristics and decrease in reliability. It is possible to connect the element to the wiring and to connect the wirings.

[Brief description of drawings]

FIG. 1 is a sectional view showing the shape of a contact hole according to a first embodiment of the present invention.

FIG. 2 is a sectional view of the shape of a contact hole according to a second embodiment of the present invention.

FIG. 3 is a sectional view showing the shape of a contact hole according to a third embodiment of the present invention.

FIG. 4 is a process sectional view for explaining a connection method according to a fourth embodiment of the present invention.

FIG. 5 is a process sectional view for explaining a connection method according to a fifth embodiment of the present invention.

FIG. 6 is a process sectional view for explaining a connecting method according to a sixth embodiment of the present invention.

FIG. 7 is a sectional view showing the shape of a via hole according to a seventh embodiment of the present invention.

FIG. 8 is a sectional view of the shape of a contact hole obtained by a conventional manufacturing method.

[Explanation of symbols]

11, 21, 41, 51, 61, 71 ... Substrate, 12, 1
4, 22, 25, 42, 52, 62, 72, 74 ... Insulating film, 13, 23 ... Impurity diffusion layer, 15, 28a, 28b
... Contact holes, 16, 27, 43, 53, 63,
75 ... Reaction prevention film, 17, 31 ... Ni ₃ Si film, 24,
44, 54, 65 ... Polysilicon film, 30 ... NiSi
film. 41 ... Si substrate, 45, 55, 64, 66 ... Ni
Film, 46, 56, 67, 76 ... Ni ₂ Si film.

Claims (3)

[Claims] 1. An insulating film formed on a semiconductor substrate and having a connection hole on a predetermined element or wiring provided on the semiconductor substrate; a reaction prevention film formed on at least a bottom portion of the connection hole; A semiconductor device having a silicide film which fills a contact hole and has a metal composition ratio higher than that of silicon. 2. An insulating film which is formed on a semiconductor substrate and has a plurality of connection holes of different depths on a predetermined element or wiring provided on the semiconductor substrate, and an insulating film which is formed at least on the bottom of the connection holes. A reaction prevention film and a silicide film that fills the connection hole and has a larger metal composition ratio as the connection hole is shallower, and at least one of the silicide films has a metal composition ratio higher than that of silicon. A semiconductor device characterized by being large. 3. A step of forming an insulating film having a connection hole on a semiconductor substrate on which an element or a wiring is formed, a step of forming a reaction preventing film on at least a bottom portion of the connection hole, and a silicon inside the connection hole. And a step of depositing a metal film on the entire surface and reacting the metal film with the silicon by heat treatment at a predetermined temperature to form a silicide film in which the metal composition ratio is larger than that of silicon. A method of manufacturing a semiconductor device, comprising: