JP3357782B2 - Method for manufacturing semiconductor device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

[0001] 1. Field of the Invention [0002] The present invention relates to a semiconductor device having a wiring and an electrode pattern made of a high melting point metal and a method of manufacturing the same.

[0002]

2. Description of the Related Art In recent years, demands for high integration ratio and high speed of semiconductor devices have been increasing. In order to fulfill these demands, reductions and miniaturizations between elements and element dimensions have been promoted, while resistance reduction of internal wiring materials has been studied.

[0003] Particularly, in a word line in which an RC delay appears remarkably, resistance reduction is a major problem. Therefore, recently, in order to reduce the resistance, a polycide gate having a two-layer structure of a metal silicide film and a polycrystalline silicon film has been widely adopted.

However, since the 0.25 μm generation, a gate electrode having lower resistance than polycide is required, and a polymetal gate structure comprising a refractory metal film, a reaction barrier layer, and a polycrystalline silicon film has recently been receiving attention. . For example the resistivity of tungsten is from about 1 order of magnitude smaller than in the tungsten silicide (WSi _x), it is possible to significantly reduce the RC delay.
Tungsten easily reacts with the polycrystalline silicon film by heat treatment at about 800 ° C. However, by sandwiching a reaction barrier layer between the tungsten and the polycrystalline silicon film, a low-resistance gate structure having excellent heat resistance is obtained. It can be formed. Further, a metal gate having a single layer of a high melting point metal is considered to be promising in the future, and the use of a high melting point metal is indispensable for lowering the resistance of the gate electrode.

[0005]

As described above, a polymetal structure composed of a high melting point metal, a lamination of a reaction barrier layer and a polycrystalline silicon film is expected as a next-generation low-resistance gate material. However, refractory metal films such as tungsten (W) are soluble in aqueous hydrogen peroxide or an acid-based mixed aqueous solution containing the same.

Generally, in an LSI manufacturing process, a process for removing metal contamination after forming a gate electrode pattern is required. An acid-based mixed aqueous solution containing hydrogen peroxide is used for removing metal contamination. The need for polymetal structures and metal gates remains the same,
As described above, since the refractory metal film is soluble, this process cannot be performed with the refractory metal exposed.

In order to increase the resistance of the refractory metal film to acid-based chemical treatment, there is a method of completely covering the refractory metal film with an insulating film such as a silicon oxide film or a nitride film. However, it is difficult to completely surround the high-melting-point metal film with an insulating film on a substrate having severe irregularities or on the outermost peripheral portion of the substrate.

[0008]

[Means for Solving the Problems]

(Summary) As described above, in a wiring using a high-melting-point metal film, the high-melting-point metal dissolves in an aqueous solution containing a hydrogen peroxide solution, and thus a chemical solution for removing heavy metal contamination from a semiconductor manufacturing apparatus. Processing cannot be performed.

The present invention is a method of manufacturing a semiconductor device which has been made in view of the above-mentioned problems.
Semiconductor device having electrode or wiring made of point metal
Manufacturing method, a silicon film or
Forms a silicon oxide film on which a refractory metal film is deposited.
Forming a first insulating film on the refractory metal film.
Forming the first insulating film as a mask;
Anisotropically etching the melting point metal film;
A step of covering the side surface of the metal film with a second insulating film;
A step of heating the refractory metal film in the
It is a sign.

[0010] The second means of the present invention is made of a refractory metal.
Method for manufacturing a semiconductor device having electrodes or wirings
A silicon film or silicon acid on the substrate to be processed.
Of forming a passivation film and depositing a refractory metal film on it
Forming a first insulating film on the refractory metal film
And using the first insulating film as a mask, the refractory metal film
Anisotropically etching the side of the refractory metal film
Covering the surface with a second insulating film;
Heat the melting point metal film, and form a high melting point metal oxide layer on the surface.
Forming and treating the substrate to be treated with sulfuric acid and hydrogen peroxide.
Water, a mixed solution of sulfuric acid and hydrogen peroxide, hydrofluoric acid, ammonia,
A step of immersion in one of nitric acid and the high melting point in a reducing atmosphere.
Having a step of heating the point metal oxide layer.
ing.

Further, in the reducing atmosphere of the second means,
In the step of heating the refractory metal oxide layer,
While reducing the refractory metal oxide layer, the silicon film is acidified.
Is characterized by

[0012] A third means of the present invention is to use a high melting point metal.
Method for manufacturing a semiconductor device having electrodes or wirings
A silicon film or silicon acid on the substrate to be processed.
Forming a passivation film, and depositing a first refractory metal film thereon
Forming a first insulating film on the refractory metal film
And forming the first insulating film using the first insulating film as a mask.
Anisotropically etching the melting point metal film;
Covering the side surface of the refractory metal film with a second insulating film;
Heating the first refractory metal film in an atmosphere,
Forming a refractory metal oxide layer on the substrate,
Depositing a second refractory metal film on the plate;
The silicidation reaction of the high melting point metal film of
Sulfuric acid, hydrogen peroxide solution, sulfuric acid and hydrogen peroxide
Immerse in a mixture of water, hydrofluoric acid, ammonia, or nitric acid
And removing the unreacted second refractory metal film.
It is characterized by having.

[0013]

[0014]

[0015]

In the present invention, an electrode or wiring made of a high-melting-point metal or a high-melting-point metal film refers to not only a pure high-melting-point metal film but also a film mainly composed of a high-melting-point metal.

(Function) According to the present invention, a chemical solution containing a solution containing active oxygen, such as a solution containing hydrogen peroxide, is employed by adopting a structure in which a high melting point metal film is surrounded by a high melting point metal oxide layer. Even if the treatment is performed, there is no fear that the high melting point metal is melted away by these chemicals. Therefore, it is possible to remove only metal contamination from the manufacturing apparatus without melting the wiring.

Further, by reducing the refractory metal oxide layer after the chemical treatment, it is possible to avoid the problem that the resistance of the wiring material increases with the oxide layer. Further, the step of reducing the refractory metal oxide can be used in combination with the step of oxidizing silicon.

After the side wall of the wiring made of the high melting point metal film is surrounded by the insulating film, the high melting point metal film is oxidized to protect the portion having low resistance to the chemical treatment, especially the protection by the insulating film. Incomplete portions can be selectively protected. Further, as the high melting point metal, W, Mo,
Ni, Cu or an alloy thereof may be used.

[0020]

BEST MODE FOR CARRYING OUT THE INVENTION

<Embodiment 1> An embodiment to which the present invention is applied will be described with reference to FIG. As shown in FIG. 1A, a tungsten film 101 (thickness: 100 nm) was deposited on a single crystal silicon substrate 100 by a sputtering method.

Next, as shown in FIG. 1B, a heat treatment was performed at 450 ° C. for about 30 minutes in an oxygen atmosphere to form a tungsten oxide layer 102 having a thickness of about 50 nm on the tungsten surface.

Thereafter, the tungsten oxide layer 102 was immersed in a mixed solution of sulfuric acid and hydrogen peroxide, but the tungsten oxide layer 102 was not dissolved, and it was found that the tungsten oxide layer 102 had an effect of suppressing the dissolution of the tungsten 101 thereunder. Was.

Then, as a result of investigating the structure of the tungsten oxide layer 102 by a thin film X-ray diffraction method, diffraction peaks of tungsten as well as tungsten oxide (WO ₃ , WO _2.9 , WO _2.72 ) were observed. That is, the tungsten film 10
1 is not completely oxidized and is in a state where tungsten and tungsten oxide are mixed. Furthermore, as a result of examining the composition by the XPS method, W: O = 1: 2.4.

The tungsten oxide layer 102 is not soluble in an acid-based solution such as hydrofluoric acid or aqueous ammonia in addition to sulfuric acid and hydrogen peroxide, and is found to be resistant to these solutions. Was. The tungsten film 101 is instantaneously dissolved in the treatment with a hydrogen peroxide solution or a nitric acid solution, but by forming the tungsten oxide layer 102 on the surface thereof, it becomes possible to make the solution resistant to these solutions.

In this embodiment, the refractory metal oxide layer is formed by oxidizing the refractory metal, but the refractory metal oxide may be formed by chemical vapor deposition (CVD) or the like. Effects can be obtained. Further, in this embodiment, tungsten (W) is selected as the high melting point metal, but Mo, Ni,
Cu or an alloy thereof may be used.

Second Embodiment A case where the present invention is applied to a gate electrode of a field effect transistor (MOSFET) will be described with reference to FIG.

First, as shown in FIG. 2A, a gate oxide film 201 (5 nm thick) is formed on a substrate 200 made of single crystal silicon, and a polycrystalline silicon film 202 (film) is formed thereon by CVD. (Thickness 100 nm). A tungsten nitride film 203 (5 nm thick) was deposited thereon by a reactive sputtering method. Subsequently, a tungsten film 204 (thickness: 100 nm) was deposited thereon by a sputtering method.

Thereafter, as shown in FIG.
By performing a heat treatment at about ° C, the tungsten film 204
A very thin WSiN layer 205 is formed at the interface between the substrate and the polycrystalline silicon film 202.

Next, a silicon nitride film 206 (200 nm thick) was deposited thereon by the CVD method. Note that the above heat treatment may be combined with the step of forming the silicon nitride film 206 having a film formation temperature of about 800 ° C.

Thereafter, a photoresist (thickness: 1 μm) is applied on the silicon nitride film 206 by spin coating, and the photoresist is exposed to light through a photomask and developed to form a resist pattern having a width of, for example, 0.25 μm. 207 are formed.

Next, as shown in FIG. 3A, the silicon nitride film 206 was etched along the resist pattern 207 using a dry etching apparatus. The remaining resist pattern 207 was peeled off by O ₂ ashing.

Further, as shown in FIG. 3B, the tungsten (W) film 204, the WSiN layer 205, and the polycrystalline silicon film 202 were etched using the silicon nitride film 206 as an etching mask.

Thereafter, as shown in FIG. 3C, oxidation was performed at 400 ° C. for about 10 minutes in an oxygen atmosphere, for example.
By this oxidation, the side wall portion 20 of the tungsten film 204 is formed.
8 is oxidized by about 200 angstroms. As a result of analyzing the composition of the side wall portion, the composition was W: O = 1: 2.
It was 4.

Next, as a treatment after the etching, the substrate was immersed in, for example, a mixed solution of sulfuric acid and hydrogen peroxide solution. Here, tungsten is easily dissolved in this mixed solution, but a tungsten oxide film formed by thermal oxidation is hardly dissolved.

If the side wall of the tungsten film 204 is not covered with the oxide, the tungsten is instantaneously dissolved in the hydrogen peroxide solution, and the tungsten wiring is naturally eliminated.

However, by protecting the side wall portion with the oxide, even if the substrate to be processed is immersed in a mixed solution of sulfuric acid and hydrogen peroxide, the wiring surrounded by the tungsten oxide is not dissolved. It is possible to remove only metal contamination from an etching device such as aluminum, iron, and titanium.

As shown in FIG. 3D, after that, in order to recover the irradiation damage of the thin silicon oxide film 201 shaved during the etching of the polycrystalline silicon 202 and to round the corner portion 209 of the bottom of the polycrystalline silicon film, N while controlling the respective gas partial pressure at ₂ / H ₂ / H ₂ in O atmosphere, 700-900
The silicon was selectively oxidized at ℃. Here, for example, the partial pressure ratio of H ₂ and H ₂ O in the atmosphere is such that the value of H ₂ O / H ₂ is 0.0.
1 or more and 1 or less. As a result of this oxidation, only silicon is oxidized, and a decrease in reliability due to electric field concentration at the bottom corner portion 209 can be prevented.

In this oxidizing atmosphere, since the tungsten oxide is reduced to tungsten, the tungsten film 20
Four sidewall portions 208 return to tungsten. As a result, it is possible to form a highly reliable gate electrode without dissolving the refractory metal that is the electrode material.

In this embodiment, the reducing atmosphere is N
_{Although a 2} / H ₂ / H ₂ O atmosphere was used, a similar effect was confirmed in a trace amount of oxygen, a trace amount of water vapor, a mixed gas atmosphere of H ₂ and O ₂ , or a mixed gas atmosphere of CO and CO ₂ .

<Embodiment 3> FIG. 3 shows a case where the present invention is applied to a field effect transistor (MOSFET).
This will be described with reference to FIG.

First, as shown in FIG. 4A, an element isolation 301 and a gate oxide film 302 (thickness: 5 nm) are formed on a substrate 300 made of single crystal silicon, and CVD is performed thereon.
A polycrystalline silicon film 303 (thickness: 100 nm) was deposited by the method. A tungsten nitride film 304 (thickness: 5 nm) was deposited thereon by a reactive sputtering method. Subsequently, a tungsten film 305 (thickness: 100 nm) was deposited thereon by a sputtering method.

Thereafter, as shown in FIG.
By performing a heat treatment at about ° C, the tungsten film 305 is formed.
An ultra-thin WSiN layer 306 is formed at the interface between the substrate and the polycrystalline silicon film 303.

Next, a silicon nitride film 307 (200 nm thick) was deposited thereon by the CVD method. Note that the above heat treatment may be combined with the film formation step of the silicon nitride film 307 having a film formation temperature of about 800 ° C.

Thereafter, a photoresist (thickness: 1 μm) is applied on the silicon nitride film 307 by spin coating, and the photoresist is exposed through a photomask and developed to form a resist pattern having a width of, for example, 0.25 μm. 308 is formed.

Next, as shown in FIG. 4C, the silicon nitride film 307 was etched along the resist pattern 308 using a dry etching apparatus. The remaining resist pattern 308 was peeled off by O ₂ ashing.

Further, using the silicon nitride film 307 as an etching mask, the tungsten (W) film 305 and the WSi
The N layer 306 and the polycrystalline silicon film 303 were etched.

As shown in FIG. 5A, after that, in order to recover the irradiation damage of the thin silicon film 302 shaved during the etching of the polycrystalline silicon film 303 and to round the corner portion 303a of the bottom of the polycrystalline silicon film, N while controlling the respective gas partial pressure at ₂ / H ₂ / H ₂ in O atmosphere, 700-900
The silicon was selectively oxidized at ℃. Due to this oxidation, only silicon is oxidized, and a decrease in reliability due to electric field concentration at the bottom corner can be prevented.

Next, as shown in FIG. 5B, after a shallow impurity diffusion layer 309 is formed by ion implantation or the like, a silicon nitride film 310 is formed as a side wall insulating film. As a result, the tungsten film 305 becomes the silicon nitride films 307 and 3
Surrounded by 10.

However, not all the tungsten films 305 on the substrate to be processed are covered with the silicon nitride film. For example, as shown in FIG.
It is difficult to completely cover a place with a width of about m or more. Normally, the resist pattern 308 is subjected to a heat treatment called post-bake, ultraviolet irradiation, or the like after development. This is performed in order to remove the solvent remaining in the film or to promote cross-linking of the molecules in the film to increase dry etching resistance. However, at the same time, the resist pattern 308 shrinks, resulting in a tapered shape.

Next, as shown in FIG. 6A, when the silicon nitride film 307, the tungsten 305, the WSiN layer 306, and the polycrystalline silicon film 303 are etched using the resist pattern 308 as an etching mask, naturally, these laminated structures are formed. Has a tapered shape.

Therefore, as shown in FIG. 6B, even if a silicon nitride film is deposited thereon and the sidewall insulating film 310 is formed by an etch-back method, the tungsten film 305 cannot be completely covered. Even if it can be covered, the connecting portion 311 between the silicon nitride films 307 and 310 is thin, which allows intrusion of the hydrogen peroxide solution.

Similarly, it is difficult to completely cover the refractory metal film with the silicon nitride film even at the outermost peripheral portion of the silicon substrate. Generally, the outermost peripheral portion of a silicon substrate is gripped when transported in an apparatus such as an etching apparatus. for that reason,
If the resist etc. is applied to the outermost periphery of the substrate,
When the silicon substrate is transported, the resist adheres to the transport system that grips the substrate, which causes dust.

Therefore, after the resist is applied to the silicon substrate, usually, an organic solvent such as a thinner is sprayed while rotating the silicon substrate to remove the resist at the outermost peripheral portion. We call this process a perimeter cut. However, since the peripheral cut portion is peeled off by spraying the organic solvent, the resist has a skirt over a few mm on the outermost periphery of the substrate. Therefore, the gate electrode at the outermost peripheral portion is etched in accordance with the resist pattern having a large skirt, so that the gate electrode also has a tapered shape over several mm.

Therefore, as in the case of the wide pattern, it is difficult to completely cover the outermost peripheral gate electrode with the silicon nitride film. For example, in order to avoid this problem, it is possible to form the outermost peripheral portion by exposing and developing with an exposure apparatus. However, in order to perform this step, a new exposure apparatus is required, and the problem of developing a wide pattern cannot be avoided.

Therefore, the present invention is characterized in that the high melting point metal is oxidized after forming the side wall of the insulating film. That is, as shown in FIG. 6C, after the formation of the sidewall insulating film 310, the substrate to be processed is exposed to an oxidizing atmosphere at 300 to 500 ° C. As a result, the oxidizing agent such as oxygen does not easily enter the portion completely covered by the silicon nitride films 307 and 310, so that the oxidation of the refractory metal does not proceed. However, the silicon nitride film 307 such as a wide portion of the pattern and the outermost peripheral portion of the substrate is used.
And 310, where it is difficult to completely protect the tungsten film 305, oxidation of the tungsten film 305 proceeds, and a tungsten oxide layer 312 is formed.

That is, the tungsten film 305 that is weak to the invasion of the oxidizing agent is selectively oxidized, and a tungsten oxide layer 312 is formed. Next, as a treatment after the etching, the substrate was immersed in a mixed solution of sulfuric acid and hydrogen peroxide solution. However,
The tungsten film 305 is a silicon nitride film 307, 310
Or a part of it is changed to the tungsten oxide layer 312 by the previous oxidation.

Therefore, the tungsten film 305 will not be melted by the hydrogen peroxide-based chemical treatment. This is because tungsten is easily dissolved in this chemical solution, but the tungsten oxide oxide layer 312 formed by thermal oxidation is hardly dissolved.

Therefore, even if the substrate to be processed is immersed in, for example, a mixed solution of sulfuric acid and hydrogen peroxide, the silicon nitride film 30
7, 310 and the wiring surrounded by the tungsten oxide layer 312 are not dissolved, and only metal contamination from an etching apparatus such as aluminum, iron, and titanium can be removed.

Further, as shown in FIGS. 7A and 7B, after forming a deep impurity diffusion layer 313 by ion implantation or the like, a titanium film 314 (thickness: 20 nm) was deposited by a sputtering method.

Thereafter, as shown in FIGS. 7C and 7D, a heat treatment is performed in a nitrogen atmosphere at, for example, 900 ° C. for 20 seconds to form a silicide layer 315 on the source / drain portions of the MOS transistor. . After that, element isolation 3
01 or the unreacted titanium on the silicon nitride films 307 and 310 is removed by a sulfuric acid and aqueous hydrogen peroxide solution. At this time, the tungsten film 30 used for the wiring is used.
Since 5 is protected by the silicon nitride films 307 and 310 or the tungsten oxide layer 312, it does not dissolve in the chemical solution.

Finally, as shown in FIGS. 8A and 8B, the tungsten oxide layer 312 is reduced by performing a heat treatment at 500 ° C. for about 30 minutes in an H ₂ / N ₂ atmosphere, for example. As a result, a MOS transistor using a gate electrode containing tungsten was formed.

Fourth Embodiment A case where the present invention is applied to a gate electrode of a field effect transistor (MOSFET) will be described with reference to FIG.

First, as shown in FIG. 9A, a gate oxide film 401 (5 nm thick) was formed on a substrate 400 made of single crystal silicon. A WSiN film 402 (5 nm thick) was deposited thereon by a reactive sputtering method. Subsequently, a tungsten film 403 (thickness: 100 nm) was deposited thereon by a sputtering method.

Then, a silicon nitride film 404 (200 nm thick) was deposited thereon by the CVD method. After this,
A photoresist (1 μm thick) is formed on the silicon nitride film 404.
After m) is applied by a spin coating method, the photoresist is exposed through a photomask and developed to form a resist pattern 405 having a width of, for example, 0.15 μm.

Next, as shown in FIG. 9B, the silicon nitride film 404 was etched along the resist pattern 405 using a dry etching apparatus. The remaining resist pattern 405 was peeled off by O ₂ ashing.

Further, using the silicon nitride film 404 as an etching mask, the tungsten (W) film 403 and the WSi
The N layer 402 was etched. Thereafter, as shown in FIG. 9C, oxidation was performed at 350 ° C. for about 10 minutes in an oxygen atmosphere, for example. This oxidation allows the tungsten film 40
A tungsten oxide layer 406 is formed on the sidewalls of the second and WSiN layers 403 at about 100 Å.

Next, as a treatment after the etching, the substrate was immersed in, for example, a mixed solution of sulfuric acid and hydrogen peroxide solution. Here, tungsten is easily dissolved in the mixed solution, but the tungsten oxide layer 406 formed by thermal oxidation is hardly dissolved.

Therefore, even if the substrate to be processed is immersed in a mixed solution of sulfuric acid and hydrogen peroxide, the wiring surrounded by the tungsten oxide layer 406 does not dissolve, and metal contamination from an etching device such as aluminum, iron, and titanium is caused. Only one can be removed.

As shown in FIG. 9D, after that, in order to recover the irradiation damage of the thin silicon oxide (gate oxide film) 401 shaved during the etching of the tungsten 402 and the WSiN layer 403, the same as in the second embodiment. in N ₂ / H ₂ / H
While controlling the partial pressure of each gas in a ₂ O atmosphere, 700
Selective oxidation of silicon was performed at ９００900 ° C. Due to this oxidation, only silicon is oxidized, and the thickness of the silicon oxide film 401 returns to its original state, so that a decrease in the reliability of the oxide film can be prevented. Since the tungsten oxide layer 406 is reduced to tungsten in this oxidizing atmosphere, the tungsten film 40
The sidewall portion of 2 returns to tungsten.

[0070]

According to the present invention, by adopting a structure in which the high melting point metal film is surrounded by the high melting point metal oxide layer, the high melting point metal can be treated even if a chemical solution containing hydrogen peroxide is applied. There is no need to dissolve away with these chemicals. Therefore, it is possible to remove only metal contamination from the manufacturing apparatus without melting the wiring. Further, by reducing the refractory metal oxide layer after the chemical treatment, it is possible to avoid the problem that the resistance of the wiring material increases with the oxide layer.

By oxidizing the refractory metal film after surrounding the side wall of the wiring made of the refractory metal film with the insulating film, the portion having low resistance to the chemical solution treatment, especially the protection by the insulating film, is obtained. Incomplete portions can be selectively protected.

[Brief description of the drawings]

FIG. 1 is a sectional view showing a first embodiment of the present invention.

FIG. 2 is a process sectional view showing a second embodiment of the present invention.

FIG. 3 is a process sectional view following FIG. 2;

FIG. 4 is a process sectional view showing a third embodiment of the present invention.

FIG. 5 is a process sectional view following FIG. 4;

FIG. 6 is a process sectional view following FIG. 5;

FIG. 7 is a process sectional view following FIG. 6;

FIG. 8 is a process sectional view following FIG. 7;

FIG. 9 is a process sectional view showing a fourth embodiment of the present invention.

[Explanation of symbols]

100: substrate, 101: tungsten film, 101: tungsten oxide layer, 200: substrate, 201: thin oxide film, 202: polycrystalline silicon film, 203: tungsten nitride film, 204: tungsten film, 205: WSiN
Layer, 206: silicon nitride film, 207: resist pattern, 208: tungsten oxide layer, 209: bottom edge portion of gate electrode, 300: substrate, 301: element isolation, 302: thin oxide film, 303: polycrystalline silicon film ,
304: tungsten nitride film, 305: tungsten film, 306: WSiN film, 307: silicon nitride film, 3
08: resist pattern, 309: shallow impurity diffusion layer,
310: sidewall insulating film, 311: insulating portion of silicon nitride film, 312: tungsten oxide layer, 313: deep impurity diffusion layer, 314: titanium film, 315: silicide layer,
400: substrate, 401: thin oxide film, 402: WSiN
Film, 403: tungsten film, 404: silicon nitride film, 405: resist pattern, 406: tungsten oxide layer.

──────────────────────────────────────────────────続 き Continued on the front page (58) Fields surveyed (Int. Cl. ⁷ , DB name) H01L 21/28 301 H01L 21/3205 H01L 29/78 H01L 21/336

Claims (4)

(57) [Claims] 1. A method of manufacturing a semiconductor device having an electrode or a wiring made of a high melting point metal, comprising: forming a silicon film or a silicon oxide film on a substrate to be processed; and depositing a high melting point metal film thereon. , forming a first insulating film on the refractory metal film, a step of anisotropically etching the refractory metal film and the first insulating film as a mask, the side surface of the refractory metal film having a the step of covering with a second insulating film, a step of heating the refractory metal film in an oxidizing atmosphere
The method of manufacturing a semiconductor device, characterized in that that. 2. A method for manufacturing a semiconductor device having an electrode or a wiring made of a high melting point metal, comprising: forming a silicon film or a silicon oxide film on a substrate to be processed; and depositing a high melting point metal film thereon. , forming a first insulating film on the refractory metal film, a step of anisotropically etching the refractory metal film and the first insulating film as a mask, the side surface of the refractory metal film and a step of covering with a second insulating film, and heating the refractory metal film in an oxidizing atmosphere, on the surface
Forming a refractory metal oxide layer, and subjecting the substrate to be processed to sulfuric acid, hydrogen peroxide, sulfuric acid and peroxide.
A step of immersing in a mixture of deionized water, hydrofluoric acid, ammonia, or nitric acid; and a step of heating the refractory metal oxide layer in a reducing atmosphere
The method of manufacturing a semiconductor device according to claim Rukoto to have a. 3. A step of heating the refractory metal oxide layer in said reducing atmosphere while reducing the refractory metal oxide layer, in claim 2, characterized by oxidizing the silicon film The manufacturing method of the semiconductor device described in the above. 4. A method of manufacturing a semiconductor device having an electrode or a wiring made of a high melting point metal, wherein a silicon film or a silicon oxide film is formed on a substrate to be processed, and a first high melting point metal film is deposited thereon. Performing a step of forming a first insulating film on the high melting point metal film, a step of using the first insulating film as a mask, and anisotropically etching the first high melting point metal film; Covering a side surface of the first refractory metal film with a second insulating film; heating the first refractory metal film in an oxidizing atmosphere ;
Forming a refractory metal oxide layer on the surface; and depositing a second refractory metal film on the substrate to be processed.
And a process for causing a silicidation reaction on the second refractory metal film.
And treating the substrate to be treated with sulfuric acid, hydrogen peroxide solution, sulfuric acid and peroxide solution.
Mixture Motomi, hydrofluoric acid, ammonia, immersion <br/> to one of nitric acid, a step of removing said second refractory metal film unreacted
The method of manufacturing a semiconductor device according to claim Rukoto to Yusuke.