JPH1174222A - Manufacturing of semiconductor device, and target for sputtering device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To form a metal, silicide film in a diffused layer having a shallow junction and to realize a sufficiently low resistance. SOLUTION: This method includes a step for forming a refractory metal film 12 containing silicon(Si) on a silicon(Si) layer 11, and a step for forming a metal silicide film 13 on the Si layer 11 by causing the Si layer 11 and the Si-containing refractory metal film 12 to react for silicification. As the Si- containing refractory metal film 12, a refractory metal film having a silicon concentration such that it realizes selective etching with respect to the metal silicide film 13 is used.

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 and a target for a sputtering device, and more particularly to a method for manufacturing a semiconductor device involving formation of a metal silicide and a target for a sputtering device used for forming the metal silicide.

[0002]

2. Description of the Related Art MOS type field effect transistors (hereinafter, referred to as MOS type field effect transistors)
MOSFETs) have been miniaturized in accordance with a scaling law in a method of manufacturing a semiconductor device. The technical problems arising at that time have been solved by the following conventional techniques.

[0003] It is difficult to achieve both the formation of the source / drain diffusion layer of the MOSFET with a shallow junction and the reduction of the resistance value of the source / drain diffusion layer. That is, it is effective to form the source / drain diffusion layers shallow in order to suppress the short channel effect that becomes more pronounced as the device is miniaturized. However, since the resistance values of the source / drain diffusion layers increase, the MOS transistor The current driving capability decreases. In order to avoid such a problem, for example, a method of performing an excimer laser annealing process of irradiating an excimer laser beam and heating after performing an ion implantation process for forming a source / drain diffusion layer has been proposed. I have. When the substrate is irradiated with excimer laser light, only the very surface of the substrate is heated in a short time. For this reason, excimer laser annealing is suitable for forming a shallow junction. Further, the excimer laser annealing process is performed by RTA because of the high temperature annealing process.
Compared with (Rapid Thermal Annealing), the crystallinity of the source / drain diffusion layers becomes excellent. Therefore, the source / drain diffusion layers are formed as low resistance diffusion layers.

As a method of lowering the resistance of the source / drain diffusion layers by the above excimer laser annealing, a metal silicide film made of a refractory metal such as titanium (for example, titanium silicide (eg, titanium silicide) is formed on the surface of the source / drain diffusion layers. salicide to form a TiSi _x) film] (Self-Aligned Silicidation: sALICIDE) process, IEEE (Institute of Electrical and Electron
ics Engineers) TRANSACTIONS ON ERECTRON DEVICE,
38 [2] (1991) Chin-Yuan Lu, Janmye James Sung, Rui
chen Liu, Nun-Sian Tsai, Ranbir Singh, Steaven JH
illenius, Howard C. Kirsch p.246-253. In this method, the surface of the source / drain diffusion layer is
By forming a compound of titanium and silicon, this source
Attempts to lower the resistance of the drain diffusion layer.

Further, there has been proposed a method of forming titanium silicide sufficiently thin so as not to penetrate a shallow source / drain diffusion layer. As this method, 20n
In this method, an ultra-thin titanium film having a thickness of m or less is deposited on the source / drain diffusion layer, and is reacted with the silicon substrate to form a thin titanium silicide film.

[0006] Further, a cobalt silicide film is used as a refractory metal silicide film that hardly causes agglomeration even when subjected to a high-temperature heat treatment.
ronDevices Meeting) '95 Tech. Dig., K. Goto et a
l., p449-452.

[0007]

However, in the above-described excimer laser annealing process, it is difficult to sufficiently reduce the resistance of a diffusion layer having a shallow junction because the junction depth and the resistance value are in an opposite relationship.

In the salicide process for forming the titanium silicide film, it is difficult to form a shallow source / drain diffusion layer because it is necessary to prevent leakage between the titanium silicide film and the substrate. When the source / drain diffusion layers are formed shallow, the titanium silicide film penetrates into the substrate. Therefore, in the salicide process, the resistance of the source / drain diffusion layers can be reduced, but a problem of leakage occurs. In order to solve this problem, the source / drain diffusion layers must be formed so deep that titanium silicide does not penetrate the source / drain diffusion layers. As described above, even if an excimer laser annealing process or a salicide process is performed to reduce the resistance of the source / drain diffusion layers, there are advantages and disadvantages.

In the case where ultra-thin titanium is silicided, the activation energy becomes higher, and a problem arises in that a low-resistance film cannot be stably obtained. To obtain a low-resistance thin-film titanium silicide film, heat treatment at a higher temperature is required.However, the high-temperature heat treatment agglomerates the titanium silicide film, making it difficult to obtain a low-resistance titanium silicide film. (Nikkei Microdevices, "Technical White Paper for Low-Power LSI ... Challenge to 1 milliwatt" p21
8-222).

[0010] Even in the method using a cobalt silicide film, there is a problem that spikes of locally grown cobalt silicide are suppressed to prevent an increase in leak. Spike growth of cobalt silicide is a serious problem when a cobalt silicide layer is formed from a titanium nitride (TiN) / cobalt (Co) laminated film. Although not seen, an oxide film is formed on the cobalt single layer, and the cobalt silicide layer cannot be formed to a sufficient thickness. Therefore, it is difficult to obtain a low resistance cobalt silicide layer.

[0011]

SUMMARY OF THE INVENTION The present invention is directed to a method of manufacturing a semiconductor device and a target of a sputtering apparatus, which have been made to solve the above-mentioned problems.

That is, a method of manufacturing a semiconductor device includes a step of forming a high-melting point metal film containing silicon on a silicon layer, and a step of causing a silicidation reaction between the silicon layer and the high-melting point metal film containing silicon. Forming a metal silicide film on the substrate, and using a silicon-containing high melting point metal film having a silicon concentration that is selectively etched with respect to the metal silicide film.

In the method of manufacturing a semiconductor device, a refractory metal film containing silicon is formed on a silicon layer, and a metal silicide film is formed by a silicidation reaction from the film. Even if the film is exposed to the atmosphere, the mixing of oxygen into the film is reduced because silicon atoms are contained in the film. Therefore, in the silicidation reaction from the silicon-containing high melting point metal film, the reaction between the high melting point metal and oxygen in the film hardly occurs during the reaction. Therefore, oxidation of the high melting point metal is prevented. Further, since silicon is contained in the high melting point metal film, its surface is hardly oxidized. Therefore, during the silicidation reaction, a reduction in the metal silicide film thickness due to surface oxidation of the refractory metal film is prevented, and the metal silicide film of a desired thickness is reduced without reducing the amount of the refractory metal consumed in the silicidation reaction. Is formed.

In the method of amorphizing the silicon layer before performing the silicidation reaction, the silicon atoms consumed in the silicidation reaction can be made to exist alone as atoms. Energy is reduced. That is, since it is not necessary to cut off the bond of the silicon crystal at the time of the silicidation reaction, the silicidation reaction is completed in a short time, and the reduction in the thickness of the metal silicide film due to the surface oxidation is further prevented.

In the method of performing ion implantation at the interface on the silicon layer after forming the high-melting-point metal film containing silicon and before performing the silicidation reaction, a natural oxide film on the silicon layer is formed by ion implantation. Destroyed. As a result, the crystal grains of the formed metal silicide film become small, so that the crystal of the metal silicide grows stably up to a thin line width of 0.1 μm or less.

The first target of the sputtering apparatus is made of an alloy or sintered body in which silicon is almost uniformly contained in a cobalt material.

Since the first target is made of an alloy or a sintered body in which silicon is almost uniformly contained in a cobalt material, when a film is formed on a wafer by sputtering using this target, Cobalt and silicon are deposited on the wafer corresponding to the ratio of cobalt and silicon contained in the target, and a cobalt film containing silicon is formed.

The second target of the sputtering apparatus is
It is made by incorporating a high melting point metal material and a silicon material.

In the second target, a refractory metal material and a silicon material are incorporated. When a film is formed on a wafer by sputtering using this target, the refractory metal and the silicon material are used. Cobalt and silicon are deposited on the wafer corresponding to the ratio of silicon to form a cobalt film containing silicon.

[0020]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment relating to a method of manufacturing a semiconductor device according to the present invention will be described with reference to a manufacturing process diagram of FIG.

As shown in FIG. 1A, silicon (S)
i) Refractory metal film 1 containing silicon (Si) on layer 11
As No. ₂ , for example, a cobalt silicon (Co ₂ Si) film is formed to a thickness of, for example, 15 nm. As the refractory metal film 12 containing Si, a film having a silicon concentration that is selectively etched with respect to a CoSi ₂ film formed later is used.

Next, the Si layer 11 is heat-treated. As a result, the cobalt of the refractory metal film 12 containing silicon (Si), the Si of the refractory metal film 12 containing the same Si, and the Si of the Si layer 11 undergo a silicidation reaction, and as shown in FIG. As shown, a cobalt silicide (CoSi ₂ ) film is formed on the Si layer 11 as the metal silicide film 13. When performing the heat treatment, the Si layer 11 is once exposed to the atmosphere and then carried into a heat treatment device (not shown). Therefore, the refractory metal film 12 containing Si [see FIG.
(1)], a thin oxide film (thin cobalt oxide film) 14 is formed on the surface layer.

In the preliminary experiments, the composition ratio of the refractory metal (Co) film containing Si is Co: Si = 21: 1, Co: S
When i = 9: 1 and Co: Si = 3.25: 1, selective etching was possible. On the other hand, Co: Si =
When the ratio was 1: 1, Co: Si = 1: 2, selective etching could not be performed. This etching is performed using sulfuric acid and hydrogen peroxide (H
₂ SO ₄ : H ₂ O ₂ = 15: 2). TEM was used for observation.
Co ₂ Si, which is considered to be capable of selective etching based on the results of the preliminary experiment, was used. As a result, the Co ₂ Si
Was selectively etched with respect to CoSi ₂ . For this reason, it is possible to use a Co film containing Si in which the number of Si atoms contained in the film is up to half the number of Co atoms contained in the film. .

Next, a comparative example will be described with reference to FIG. As shown in FIG. 2A, a silicon layer (Si layer)
For example, cobalt (C)
o) Form a film. At this time, Co per unit volume of the cobalt silicon (Co ₂ Si) film formed in FIG.
The Co film is formed with the number of Co atoms substantially equal to the number of atoms. Therefore, the thickness of the Co film is set to 10 nm. Next, the Si layer 21 is heat-treated. As a result, the refractory metal film 22
Co and Si of the Si layer 21 undergo a silicidation reaction,
As shown in FIG. 2B, a cobalt silicide (CoSi ₂ ) film is formed as a metal silicide film 23 on the Si layer 21. When performing the heat treatment, the Si layer 21 is once exposed to the air and then carried into a heat treatment device (not shown). Therefore, an oxide film (a mixed film of cobalt, silicon, and oxygen) 24 is formed on the surface layer of the refractory metal film 22 by reacting with oxygen in the atmosphere.

As described above with reference to FIG. 2, a single-layer high melting point metal film (Co film) 22 is changed to a metal silicide film 23.
When the CoSi ₂ film is formed, the surface of the metal silicide (CoSi ₂ ) film 23 is oxidized by the influence of oxygen that is exposed when the film is once opened to the atmosphere. When a silicidation reaction is performed from a single-layer Co film in this manner, Co
→ Co ₂ Si → CoSi → CoSi ₂
Si ₂ is formed. In this reaction, Co → Co ₂ Si
Is caused by diffusion of Co atoms, so that CoSi ₂ is not instantaneously formed. Therefore, if oxygen is present in the Co film at the time of the above reaction, the oxidation of Co proceeds, so that an oxide film is formed.

On the other hand, S described with reference to FIG.
When a metal silicide (CoSi ₂ ) 13 film is formed from a high-melting metal film (Co ₂ Si film) 12 containing i, the metal silicide film 13
Oxidation of the surface is very slight. Thus, in the case of the silicidation reaction from the refractory metal (Co ₂ Si) film 12 containing Si, the reaction in which the process of Co → Co ₂ Si in the case of the silicidation reaction from the single-layer Co film is directly removed, That is, CoSi ₂ is formed by the reaction of Co ₂ Si → CoSi → CoSi ₂ . Therefore, Co → Co ₂ S
The oxidation of Co in the process of i can be prevented. Furthermore, when the Co ₂ Si film 12 is deposited, even if the film is taken out to the atmosphere for the subsequent heat treatment, since the Si atoms are contained in the film, the incorporation of oxygen into the film is reduced. .

As a result, in the manufacturing method described with reference to FIG. 1, a reduction in the silicide film thickness due to surface oxidation of the Co film is prevented, and a thick metal silicide ( A CoSi ₂ ) film 13 is formed, and its sheet resistance decreases.

Before depositing the refractory metal film 12,
For example, when the crystal of the Si layer 11 is broken and made amorphous by ion implantation, the Si atoms consumed in the silicidation reaction can be in a state where they are not in a crystalline state but exist alone as atoms. Therefore, the activation energy of the silicidation reaction can be reduced (because it is not necessary to break the bond of the Si crystal during the reaction).
As a result, the silicidation reaction can be completed in a short time, so that the metal silicide (C
A decrease in the thickness of the oSi ₂ ) film 13 is further prevented, and the metal silicide film 13 having a desired film thickness is formed without substantially reducing the amount of Co consumed in the silicidation reaction.
Therefore, the sheet resistance is further reduced.

In the ion implantation for amorphizing the Si layer 11, an impurity for mainly amorphizing a region to be silicided is implanted. As such an impurity, for example, germanium is used. By implanting germanium in this manner, only a narrow range in the depth direction of the Si layer 11 can be made amorphous. Note that the impurities are implanted as ions.

In the ion implantation for making the Si layer 11 amorphous, an impurity for compensating crystal defects can be implanted. As such an impurity, for example, fluorine or a molecule containing fluorine such as silicon fluoride (SiF) or nitrogen is used. Note that the impurities are implanted as ions. When an impurity for compensating for such a crystal defect is implanted, a region that is not silicided also becomes amorphous. However, in an amorphous region, in other words, in a region where a crystal defect occurs, a lattice is formed. Between the Si atoms and the implanted impurities (fluorine,
Nitrogen, etc.). Therefore, especially when the substrate is doped with boron, it is possible to suppress the enhanced diffusion of boron. This is particularly effective in the well of an N-channel transistor and the source / drain of a P-channel transistor, and the switching characteristics (ON / OFF characteristics) of a MOS (or MIS) type field-effect transistor due to accelerated diffusion of boron. Deterioration is suppressed.

When a region which is not to be silicided becomes amorphous when the above-described germanium is implanted, an impurity for compensating the crystal defect may be implanted into the region.

Further, for example, by ion implantation, Co ₂ Si / Si if the crystal at the interface Oke destroyed, before forming the refractory metal (Co ₂ Si) film 12 containing Si Co ₂ Si / Si The natural oxide film (not shown) grown on the interface is also destroyed. Therefore, the metal silicide film 13 is formed by small crystal grains,
It is possible to stably grow a CoSi ₂ crystal to a thin line width of about 0.1 μm or less. Therefore, the resistance can be further reduced without being affected by the thin wire effect.

In the manufacturing method described with reference to FIG.
Forming a refractory metal film 12 containing Si on a Si layer 11;
Since the metal silicide film 13 is formed by a silicidation reaction from the film, even if the refractory metal film 12 containing Si is exposed to the atmosphere, Si atoms are contained in the film. The mixing of oxygen into the gas is reduced. Therefore, in the silicidation reaction from the refractory metal film 12 containing Si, the refractory metal and oxygen hardly react in the film during the reaction, so that oxidation of the refractory metal is prevented. Further, since silicon is contained in the high melting point metal film, its surface is hardly oxidized.
Therefore, during the silicidation reaction, a reduction in the thickness of the metal silicide film 13 due to surface oxidation of the refractory metal film is prevented, and the desired thickness of the refractory metal film is reduced without reducing the amount of the refractory metal consumed in the silicidation reaction. A metal silicide film 13 is formed.

As described above, the refractory metal film 12 containing Si, which is an extremely thin film of about 20 nm or less, is formed.
Can be used to form the metal silicide film 13. In addition, the sheet resistance of the metal silicide film 13 is reduced, and the low-resistance metal silicide film 13 can be formed up to a region having a small line width of 0.1 μm or less without depending on the line width. Further, since the metal silicide film 13 is formed by using the refractory metal 12 containing Si as an extremely thin film, the depth of the consumed Si layer 11 can be reduced. When forming the silicide film 13,
The metal silicide film 13 can be formed even on a very shallow junction of about 0.15 μm or less. Therefore, the silicide technology can be used also for MOS transistors of the sub-half micron generation or later.

Next, an example in which the manufacturing method described with reference to FIG. 1 is applied to a MOS transistor will be described with reference to FIGS.
This will be described with reference to a manufacturing process diagram of FIG.

As shown in FIG. 3A, an element isolation insulating film 32 for isolating an element formation region on a semiconductor substrate (for example, a Si substrate) 31 is formed by, for example, a local oxidation method [for example, LOC.
OS (Local Oxidation of Silicon) method] to a thickness of, for example, 300 nm. Subsequently, although not shown, ion implantation for forming a well, so-called D
Deep ion implantation, ion implantation for forming a channel stop layer, ion implantation for adjusting Vth, and the like are performed.

Next, as shown in FIG. 3B, the semiconductor substrate 31 is subjected to a thermal oxidation treatment to form a gate insulating film 33 of, for example, 4 nm in thickness on the surface of the element forming region using SiO ₂ .

Next, as shown in FIG. 3C, a polysilicon film 34 serving as a gate material is deposited on the gate insulating film 33 to a thickness of, for example, 200 nm by, for example, a CVD method.

Next, as shown in FIG. 3D, the polysilicon film 34 is patterned using a lithography technique and an etching technique to form a gate electrode 35. At this time, the gate insulating film 33 is also patterned.

Then, as shown in FIG. 4 (5), the semiconductor substrate 31 on both sides of the gate electrode 35 is subjected to LDD (light) by ion implantation using the gate electrode 35 as a mask.
tlyDoped Drain) 36, 37 are formed. In some cases, so-called pocket ion implantation or the like may be performed.
Subsequently, an insulating film serving as a side wall is formed of, for example, SiO ₂ so as to cover the gate electrode 35, and then etched back to form a side wall insulating film 38, 39 on the side wall of the gate electrode 35, for example, about 0.1 μm. Formed to a width of

Next, as shown in FIG. 4 (6), impurities for forming source / drain diffusion layers in the semiconductor substrate 31 are formed by ion implantation using the gate electrode 35 and the sidewall insulating films 38 and 39 as a mask. Is ion-implanted. Thereafter, activation annealing is performed to form an LDD 3 on the semiconductor substrate 31 on both sides of the gate electrode 35 and on the side of the gate electrode 35 (below the sidewalls 26 and 37).
Source / drain diffusion layers (corresponding to the Si layer 11 in FIG. 1) 41 and 42 are formed so as to leave 6 and 37. In forming a shallow junction, arsenic (As) is ion-implanted with an implantation energy of about 20 keV when forming an NMOS transistor, and boron ketone (BF ₂ ) is about 10 keV when forming a PMOS transistor. Is implanted with the implantation energy of. The activation annealing is performed by RTA (Rapid Thermal Annealing).
, For example, at 1000 ° C. for about 10 seconds. Under such conditions, the diffusion depth Xj = 0.1 μm to 0.15 μm
Is formed.

Subsequently, for example, germanium ions (Ge ⁺ ) are implanted into the entire surface of the Si substrate 31 by an ion implantation method, and the surface layer of the Si substrate 31 is made amorphous. As an example of the ion implantation conditions, the implantation energy is set to 20 keV and the dose is set to 1 × 10 ¹⁴ / cm ² .

Next, a refractory metal film 51 containing Si (hereinafter referred to as a Co ₂ Si film) 51 is formed on the entire surface of the Si substrate 31.
For example, it is deposited by sputtering to a thickness of about 15 nm. Then, for example, silicon ions (Si ⁺ ) are implanted into the Si substrate 31 from above the Co ₂ Si film 51 by an ion implantation method. The ion implantation conditions at this time are, for example, an implantation energy of 15 keV and a dose of 3
× 10 ¹⁴ pieces / cm ² . By this ion implantation, a natural oxide film (not shown) generated at the interface between the Si substrate 31 and the Co ₂ Si film 51 is destroyed.

Next, as shown in FIG.
A first heat treatment at 550 ° C. is performed on the i-substrate 31. By this first heat treatment, the Co ₂ Si film 51 and the Si substrate 31 are formed.
Are made into silicidation reaction to form cobalt silicide (CoSi ₂ ) films 52, 53, 54 only on the gate electrode 35 and the source / drain diffusion layers 41, 42.

Next, unreacted Co ₂ Si film 51 on element isolation insulating film 32, sidewall insulating films 38 and 39, etc.
Is removed by wet etching using, for example, sulfuric acid and hydrogen peroxide. Next, as shown in FIG.
A second heat treatment is performed at 800 ° C. to make the crystallinity of the i ₂ films 52, 53, and 54 more complete. By this second heat treatment, junction leak in the source / drain diffusion layers 41 and 42 is reduced.

Thereafter, although not shown, the gate electrode 35 is formed on the Si substrate 31 by a method similar to the conventional technique.
Is formed, and CoS is formed on the interlayer insulating film.
Source / drain diffusion layer 4 via i ₂ films 53 and 54
A contact hole leading to 1, 42, etc. is formed, a plug is formed in the contact hole, a wiring connected to the plug is formed, and a MOS transistor is manufactured.

The various conditions described in the above-described manufacturing method are merely examples, and the present invention is not limited to these values, and conditions suitable for device characteristics are appropriately selected.

[0048] For example the thickness of the Co ₂ Si film 51, when the depth of the source and drain diffusion layers 41 and 42 is shallower than 0.15 [mu] m, CoSi ₂ film 53 is formed and C
The source / drain diffusion layer 4 under the oSi ₂ films 53 and 54
The film thickness of 1,42 remains. For example, when the depth of the source / drain diffusion layers 53 and 54 is set to 0.15 μm, the Co ₂ Si film 51 is formed to a thickness of, for example, about 20 nm or less.

The implanted atoms (or implanted molecules) and the implantation conditions in the ion implantation for making the Si substrate 31 amorphous are not limited to the above-mentioned values, but are limited to the regions consumed in the silicide reaction. Any condition may be used as long as the Si crystal can be made amorphous.

[0050] The ion implantation performed from the top Co ₂ Si film 51 is also not limited to the values shown above, at the atomic or molecular not impair the silicidation reaction, Co ₂ Si
Any condition can be used as long as it can destroy a natural oxide film (not shown) at the / Si substrate interface. In particular, it is preferable that both the implantation energy and the dose be small in the sense that crystal defects in the Si substrate 31 are not formed more than necessary, in other words, more than promoting the silicidation reaction.

The Co ₂ Si film 51 to be further deposited is not limited to this, and the Si concentration in Co is set to Co ₂ S
S that is smaller than i-film and whose surface oxidation is suppressed
i concentration of Co ₂ Si _x (provided that 0 <x ≦ 1) may be any.

In the above description of the embodiment, the process of forming a cobalt silicide (CoSi ₂ ) film by _two heat treatments has been described. However, the method of the present invention is also applied to the case of forming CoSi ₂ by one heat treatment. It is effective to do. That is, in the above-described embodiment, the second heat treatment may be omitted.

The method of the present invention for obtaining the CoSi ₂ films 52 to 54 from the Co ₂ Si film 51 is based on titanium silicide (TiSi ₂ ), platinum silicide (PtSi ₂ ),
The present invention can be applied to formation of nickel silicide (NiSi), molybdenum silicide (MoSi ₂ ), and the like. In that case, for example, from Ti ₂ Si to TiSi ₂
To obtain PtSi ₂ from Pt ₂ Si, to obtain Ni ₂ Si
NiSi from Mo ₂ Si, MoSi ₂ from Mo ₂ Si, and the like.

Next, C is used as the refractory metal film containing Si.
A first embodiment of a target mounted on a sputtering device used when forming an o ₂ Si film by sputtering will be described with reference to a schematic configuration sectional view of FIG.

As shown in FIG. 5, the first target 61
Is a material in which Si is uniformly contained in a Co material.
The content of Si is defined so that the composition ratio of o and Si becomes a desired value. Further, it is preferable to determine the Si content in the Co material in consideration of the plasma density on the first target 61.

The first target 61 is, for example, C
It may be a solid solution formed by fusing and solidifying an o material and a Si material, or a sintered body obtained by sintering a mixture obtained by mixing or kneading a Co powder and a Si powder.

Although not shown, the first target 61 is made of an alloy or a sintered body in which silicon is almost uniformly contained in a cobalt material. When a film is formed on a wafer, cobalt and silicon are deposited on the wafer in accordance with the ratio of cobalt and silicon contained in the first target 61, and a cobalt film containing silicon is formed. .

Next, C is used as the refractory metal film containing Si.
A second embodiment of a target mounted on a sputtering apparatus used when forming an o ₂ Si film by sputtering will be described with reference to a schematic configuration sectional view of FIG.

As shown in the plan view of (1) in FIG. 6 and the cross-sectional view taken along the line AA in (1) of (2), the refractory metal material 82 The configuration is such that the Si material 83 and the Si material 83 are combined in shape. In the second target 81 of this example,
Refractory metal materials 82 and Si materials 83 are alternately arranged concentrically. Note that the ratio between the high melting point metal material 82 and the Si material 83 may be appropriately determined depending on, for example, the width of each annular portion. For example, when a film is formed so as to have a composition ratio of Co: Si = 2: 1, the area ratio of the Co: Si target is 0.8 in consideration of the sputtering ratio of Co and Si.
2: 1. Further, it is desirable to determine the content of Si in the Co material of the target in consideration of the plasma densities on Co and Si of the target. The area ratio is defined as the area of the high melting point metal material 82 exposed on the sputtering surface of the target and the Si material 8
3 represents the ratio to the area.

Although not shown, the second target 81 is formed by incorporating a high melting point metal material 82 and a silicon material 83 onto the wafer by sputtering using the second target 81. When a film is formed on the wafer, cobalt and silicon are deposited on the wafer corresponding to the ratio of the refractory metal and silicon,
A cobalt film containing silicon is formed.

The high melting point metal material 8 of the second target 81
The configuration of 2 and the Si material 83 is not limited to the above configuration. Other examples of the configuration of the second target are described below.
This will be described with reference to the plan view of FIG. In FIG. 7, the high melting point metal material is indicated by a black portion, and the Si material is indicated by a white portion.

As shown in FIG. 7A, the Si material 83
As shown in (2), a target 81a in which a high melting point metal material 82 is radially arranged, and a Si material 83 is radially arranged in the high melting point metal material 82 and a high melting point metal material 8
As shown in (3), the targets 81b and (3) are arranged so that the ratio between the Si material 83 and the Si material 83 is concentric.
A target 81c in which the refractory metal material 82 and the Si material 83 are arranged in a checkerboard pattern, as shown in (4), a target 81d in which the refractory metal material 82 is arranged in the Si material 83 in a dot-like manner and vertically and horizontally, As shown in (5), a target 81e in which a refractory metal material 82 is radially and concentrically arranged in a Si material 83, as shown in (6),
As shown in (7), a target 81f in which a high melting point metal material 82 is arranged in a lattice in a Si material 83, as shown in (7).
g. In the case where the high melting point metal material 82 described in the above (4) is arranged in a dot shape and vertically and horizontally, the shape of the high melting point metal material 82 forming one point is circular, square,
Any shape such as a cross shape may be used.

Each of the targets described with reference to FIGS. 6 and 7 may have a configuration in which the arrangement of the Si material and the refractory metal material is reversed. The ratio between the high melting point metal material 82 and the Si material 83 may be appropriately determined according to, for example, the size (eg, width, length, etc.), quantity, etc. of each material portion. The refractory metal material includes cobalt,
Nickel, molybdenum, titanium, tungsten, platinum,
It can be used by selecting from palladium, hafnium, chromium, zirconium, gold and the like.

[0064]

As described above, according to the method of manufacturing a semiconductor device of the present invention, a refractory metal film containing silicon is formed on a silicon layer, and a metal silicide film is formed by a silicidation reaction from the film. Since it is formed, a reaction between the high melting point metal and oxygen hardly occurs due to silicon in the high melting point metal film containing silicon. Therefore, oxidation of the refractory metal is prevented, so that a reduction in the thickness of the metal silicide film can be prevented, and a metal silicide film having a desired thickness can be formed. Therefore, it is possible to form a silicide into a shallow junction, and to reduce the resistance.

According to the first and second targets of the present invention, the target is made of an alloy or sintered body in which silicon is almost uniformly contained in the cobalt material. Thus, a refractory metal (eg, Co ₂ Si) film containing silicon can be formed.

[Brief description of the drawings]

FIG. 1 is a manufacturing process diagram of an embodiment relating to a method of manufacturing a semiconductor device of the present invention.

FIG. 2 is a manufacturing process diagram of a comparative example with respect to the embodiment.

FIG. 3 is a manufacturing process diagram (part 1) of an example in which the manufacturing method of the embodiment is applied to a MOS transistor;

FIG. 4 is a manufacturing process diagram (part 1) of an example in which the manufacturing method of the embodiment is applied to a MOS transistor;

FIG. 5 is a schematic configuration sectional view of a first embodiment relating to a target of the present invention used in a sputtering apparatus.

FIG. 6 is an explanatory diagram of a second embodiment relating to a target of the present invention used in a sputtering apparatus.

FIG. 7 is an explanatory diagram of another configuration example related to the target of the second embodiment.

[Explanation of symbols]

11: silicon (Si) layer, 12: high melting point metal film containing silicon (Si), 13: metal silicide film

Claims (31)

[Claims] A step of forming a high-melting point metal film containing silicon on a silicon layer; and causing a silicidation reaction between the silicon layer and the high-melting point metal film containing silicon to form a metal silicide film on the silicon layer. And forming a high melting point metal film containing silicon having a silicon concentration selectively etched with respect to the metal silicide film. 2. The method for manufacturing a semiconductor device according to claim 1, wherein the refractory metal film containing silicon is formed of a cobalt film containing silicon, and the silicon film containing silicon contains silicon atoms contained in the film. A method of manufacturing a semiconductor device, wherein the number of silicon atoms is up to 1/2 of the number of cobalt atoms contained in the film. 3. The method of manufacturing a semiconductor device according to claim 1, wherein said semiconductor device is formed of an insulated gate transistor, and a source / drain diffusion layer of said insulated gate transistor is formed in said silicon layer. When the depth of the source / drain diffusion layer is set to within 150 nm and the refractory metal film containing silicon is formed to a thickness not less than the thickness at which the metal silicide film is formed and the metal silicide film is formed. A method for manufacturing a semiconductor device, wherein the source / drain diffusion layer is formed to have a remaining film thickness. 4. The method for manufacturing a semiconductor device according to claim 1, wherein the silicon layer is made amorphous before the silicidation reaction is performed. 5. The method for manufacturing a semiconductor device according to claim 2, wherein the silicon layer is made amorphous before the silicidation reaction is performed. 6. The method for manufacturing a semiconductor device according to claim 3, wherein the silicon layer is made amorphous before the silicidation reaction is performed. 7. The method of manufacturing a semiconductor device according to claim 4, wherein the amorphization of the silicon layer is performed by implanting impurities into the silicon layer by ion implantation. Method. 8. The method of manufacturing a semiconductor device according to claim 5, wherein the silicon layer is made amorphous by implanting impurities into the silicon layer by ion implantation. Method. 9. The method of manufacturing a semiconductor device according to claim 6, wherein the amorphization of the silicon layer is performed by implanting impurities into the silicon layer by ion implantation. Method. 10. The method for manufacturing a semiconductor device according to claim 7, wherein said impurity is an impurity which mainly turns the region to be silicided into an amorphous state. 11. The method for manufacturing a semiconductor device according to claim 8, wherein the impurity is an impurity that mainly turns the region to be silicided into an amorphous state. 12. The method for manufacturing a semiconductor device according to claim 9, wherein the impurity is an impurity that mainly turns the region to be silicided into an amorphous state. 13. The method of manufacturing a semiconductor device according to claim 10, wherein germanium is used as the impurity that mainly amorphizes the region to be silicided. 14. The method of manufacturing a semiconductor device according to claim 11, wherein germanium is used as the impurity that mainly amorphizes the region to be silicided. 15. The method of manufacturing a semiconductor device according to claim 12, wherein germanium is used as the impurity that mainly amorphizes the region to be silicided. 16. The method of manufacturing a semiconductor device according to claim 7, wherein the impurity is an impurity that compensates for a crystal defect. 17. The method for manufacturing a semiconductor device according to claim 8, wherein an impurity for compensating crystal defects is used as the impurity. 18. The method for manufacturing a semiconductor device according to claim 9, wherein said impurity is an impurity for compensating crystal defects. 19. The method for manufacturing a semiconductor device according to claim 16, wherein the impurity for compensating for the crystal defect is fluorine, a molecule containing fluorine, or nitrogen. 20. The method for manufacturing a semiconductor device according to claim 17, wherein the impurity for compensating for the crystal defect is fluorine, a molecule containing fluorine, or nitrogen. 21. The method for manufacturing a semiconductor device according to claim 18, wherein the impurity for compensating for the crystal defect is fluorine, a molecule containing fluorine, or nitrogen. 22. The method of manufacturing a semiconductor device according to claim 1, wherein after the formation of the refractory metal film containing silicon and before the silicidation reaction is performed, ion implantation is performed on an interface on the silicon layer. A method for manufacturing a semiconductor device, comprising: 23. The method of manufacturing a semiconductor device according to claim 2, wherein after forming the refractory metal film containing silicon and before performing the silicidation reaction, ion implantation is performed on an interface on the silicon layer. A method for manufacturing a semiconductor device, comprising: 24. The method of manufacturing a semiconductor device according to claim 3, wherein after forming the refractory metal film containing silicon and before performing the silicidation reaction, ion implantation is performed on an interface on the silicon layer. A method for manufacturing a semiconductor device, comprising: 25. The method of manufacturing a semiconductor device according to claim 22, wherein the refractory metal film is formed of a cobalt film containing silicon, and silicon atoms contained in the cobalt film containing silicon after the ion implantation. Characterized in that the number of GaAs is at most half the number of cobalt atoms contained in the film. 26. The method of manufacturing a semiconductor device according to claim 23, wherein the refractory metal film is formed of a cobalt film containing silicon, and silicon atoms contained in the cobalt film containing silicon after the ion implantation. Characterized in that the number of GaAs is at most half the number of cobalt atoms contained in the film. 27. The method of manufacturing a semiconductor device according to claim 24, wherein the refractory metal film is formed of a cobalt film containing silicon, and silicon atoms contained in the cobalt film containing silicon after the ion implantation. Characterized in that the number of GaAs is at most half the number of cobalt atoms contained in the film. 28. A target for a sputtering apparatus, wherein the target is made of an alloy or a sintered body in which silicon is substantially uniformly contained in a cobalt material. 29. The sputtering apparatus according to claim 28, wherein the target contains at least half of the number of silicon atoms of cobalt atoms in the target. Target. 30. A target for a sputtering apparatus, wherein the target includes a refractory metal material and a silicon material incorporated therein. 31. The target for a sputtering apparatus according to claim 30, wherein the high-melting point metal material is made of a cobalt material, and at least silicon atoms up to half the number of cobalt atoms in the target are contained in the target. A target for a sputtering apparatus, wherein the target is included.