JPH0621059A - Semiconductor device and manufacture thereof - Google Patents

Abstract

PURPOSE:To prevent oxidation of interconnections made of polyside, to eliminate a stress at the interconnection and an insulating film formed around the interconnection and to obtain high yield and high reliability by increasing a thickness of a layer insulating film on the interconnection of the polyside thicker than that of a layer insulating film on the other interconnection. CONSTITUTION:The semiconductor device comprises at least three-layers or more of interconnections. In such a device, a thickness Ta of a layer insulating film between a first interconnection 107 and a second interconnection of polyside formed of a polycrystalline silicon film 105 and a silicide film 106 formed under the interconnection 107 is thicker than that Tb of a second layer insulating film formed between a third interconnection 103 and the interconnection 107 formed under the second interconnections 105, 106. Thus, oxygen is diffused in the interlayer insulating film by later heat treating in an atmosphere containing oxygen to increase a time arriving at the interconnection, thereby scarcely oxidizing due to reaction of the silicon with the oxygen in the interconnection.

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 a MIS type semiconductor device having a wiring made of polycide composed of a polycrystalline silicon film and a silicide film on a semiconductor substrate, The manufacturing method is related.

[0002]

2. Description of the Related Art In a conventional MIS type semiconductor device,
After forming a wiring made of polycide composed of a polycrystalline silicon film and a silicide film, a silicon oxide film was deposited as an interlayer insulating film, and the silicon oxide film was left as it was.

[0003]

However, in the conventional semiconductor device and its manufacturing method, since the subsequent heat treatment is performed in an atmosphere containing oxygen, an interconnection made of polycide composed of a polycrystalline silicon film and a silicide film is formed. Oxidation occurs due to the reaction of silicon and oxygen inside, and stress is generated in the wiring and the insulating film around it. Therefore, current leakage between the wirings is likely to occur, and the insulating film around the wirings is easily broken, which causes a problem that the semiconductor device causes defective characteristics.

Therefore, the present invention solves such a problem,
An object of the present invention is to provide a semiconductor device with high yield and high reliability, and a manufacturing method thereof.

[0005]

According to the present invention, in a semiconductor device having at least three layers of wiring, a first wiring and a polycrystalline silicon film or a silicide film formed under the first wiring are provided. The first interlayer insulating film between the second wirings made of polycide is composed of a second wiring formed between the third wirings formed under the second wirings and the first wirings. A semiconductor device having at least three or more layers of wiring,
Forming a first wiring on a semiconductor substrate;
A step of forming a first insulating film on the wiring, a step of depositing a polycrystalline silicon film on the first insulating film, a step of forming a silicide film on the polycrystalline silicon film, Selectively remove the crystalline silicon film and the silicide film,
Forming a second wiring, and forming a second wiring on the second wiring.
A step of depositing an interlayer insulating film, a step of selectively reducing the second interlayer insulating film on a region excluding the second wiring, and a step of forming a third wiring on the second interlayer insulating film. It is characterized by including a step of forming.

In a semiconductor device having at least three layers of wiring, an interlayer insulating film formed in the middle and on the wiring made of polycide composed of a polycrystalline silicon film and silicide, A step of depositing a polycrystalline silicon film on a semiconductor substrate, and a silicide film formed on the polycrystalline silicon film, in a semiconductor device including at least three layers of wirings, including a silicon nitride film And a step of selectively removing the polycrystalline silicon film and the silicide film to form a second wiring, and a step of depositing a silicon nitride film on the second wiring. .

In a semiconductor device having at least three layers of wiring, an interlayer insulating film formed in the middle and on a wiring made of polycide composed of a polycrystalline silicon film and silicide, a step of depositing a polycrystalline silicon film on a semiconductor substrate in a semiconductor device having at least three or more wiring layers, characterized in that it contains SiO _x N _y satisfying x, y>0; A step of forming a silicide film on the crystalline silicon film; a step of selectively removing the polycrystalline silicon film and the silicide film to form a second wiring; and a step of depositing a silicon oxide film on the second wiring. a step of, then comprising a step of performing heat treatment in an atmosphere containing NH _3, the NH ₃
The atmosphere containing is characterized by being diluted only with NH ₃ , or with N ₂ , an inert gas.

In a semiconductor device having at least three layers of wiring, a step of depositing a polycrystalline silicon film on a semiconductor substrate, a step of forming a silicide film on the polycrystalline silicon film, A step of selectively removing the polycrystalline silicon film and the silicide film to form a second wiring, a step of depositing a silicon oxide film on the second wiring, and then in an atmosphere containing N ₂ O The method is characterized in that the atmosphere containing N ₂ O is diluted with N ₂ O alone or N ₂ and an inert gas.

In a semiconductor device having at least three layers of wiring, a step of depositing a polycrystalline silicon film on a semiconductor substrate, a step of forming a silicide film on the polycrystalline silicon film, A step of selectively removing the polycrystalline silicon film and the silicide film to form a second wiring, a step of depositing a silicon oxide film on the second wiring, and then nitrogen ions in the silicon oxide film. Is included.

[0010]

In the semiconductor device and the method of manufacturing the same according to the present invention, the silicon oxide film as the interlayer insulating film on the wiring made of polycide composed of the polycrystalline silicon film and the silicide film is thickened to prevent the subsequent oxygen. By heat treatment in an atmosphere containing oxygen, the time for oxygen to diffuse into the interlayer insulating film and reach the wiring is lengthened, and oxidation due to the reaction between silicon and oxygen in the wiring is less likely to occur.

Further, a silicon nitride film or SiO _x N _y (hereinafter referred to as oxynitride) satisfying x, y> 0 is used as an interlayer insulating film on the wiring made of polycide composed of a polycrystalline silicon film and a silicide film. Is formed), oxygen is prevented from reaching the wiring, and oxidation due to a reaction between silicon and oxygen in the wiring is less likely to occur.

[0012]

EXAMPLES The present invention will be described in detail below based on examples. 1, 3, and 5 are sectional views of a semiconductor device according to an embodiment of the present invention, and FIGS. 2, 4, 6, and 8 are manufacturing methods of a semiconductor device according to an embodiment of the present invention. FIG. 6 is a cross-sectional view along the order of steps.

Now, description will be given in order of steps based on the embodiment of the present invention shown in FIG.

Here, 201 is a silicon substrate, and 2
Reference numerals 02, 204 and 207 are silicon oxide films, and 20
3, 205 and 209 are polycrystalline silicon, 206 is Mo (molybdenum), and 208 is a resist.
First, a thermal oxide film or a CVD film is formed on the silicon substrate 201.
A silicon oxide film 202 is formed by the method. (Fig. 2
(See (a)) Next, according to the CVD method, in a monosilane atmosphere at a temperature of 600 ° C. to 650 ° C., about 100 n is formed on the entire surface of the silicon substrate.
A polycrystalline silicon film 203 having a thickness of m to 500 nm is deposited, and P (phosphorus) ions are diffused in the polycrystalline silicon film by heat treatment using POCl ₃ at about 900 ° C. for several tens of minutes. Alternatively, BF ₂ ions that are P-type impurities or As (arsenic) and P (phosphorus) ions that are N-type impurities have an energy of 30 keV to 120 keV and a dose amount of 1
Implantation is performed under the condition of × 10 ¹⁴ cm ^-2 or more to form a high concentration impurity layer.

Next, after patterning by the photo-etching method, etching is performed under a pressure of several mTorr using a mixed gas of Freon 123 and O ₂ and SF ₆ to form a polycrystalline silicon film 203. One wiring is formed.
(See FIG. 2B.) Then, a silicon oxide film 204 of 100 nm to 200 nm is deposited by the CVD method, patterned by the photolithography method, and then the silicon oxide film is selectively etched. (See FIG. 2 (c)) Then, by thermal oxidation or CVD for 5 minutes to 1 hour in an oxygen atmosphere diluted with Ar (argon) or N _{2 at a} temperature of 900 ° C. to 1000 ° C. to 50% or less.
A silicon oxide film of 10 nm to 30 nm is formed.

Next, a temperature of 600 ° C. to 6 ° C. is obtained by the CVD method.
A polycrystalline silicon film 20 of about 100 nm to 300 nm is formed on the entire surface of the silicon substrate in a monosilane atmosphere at 50 ° C.
5 was deposited and POCl ₃ was used to form a number 1 at around 900 ° C.
P (phosphorus) in the polycrystalline silicon film by heat treatment for 0 minutes
Diffuse ions. Alternatively, BF ₂ which is a P-type impurity
Ions or As (arsenic), which is an N-type impurity, P
(Phosphorus) ions with an energy of 30 keV to 120 keV,
Implantation is performed under the condition of a dose amount of 1 × 10 ¹⁴ cm ⁻² or more to form a high concentration impurity layer.

Further, Mo (molybdenum) or, on the polycrystalline silicon film, is formed by the CVD method or the sputtering method.
Mo206 containing Si is deposited from 50 nm to 200 nm. Next, after patterning by a photo-etching method, a mixed gas of Freon 123 and O ₂ and SF ₆ is used,
Etching is performed under a pressure of several mTorr to form a second wiring. (See FIG. 2D) Then, a silicon oxide film 207 having a thickness of about 200 nm is deposited on the entire surface by the CVD method. (See FIG. 2E.) Next, after patterning is performed by the photolithography method, the silicon oxide film on the region other than the second wiring layer region is selectively changed by the reaction gas CHF ₃ by about 100 nm. Isotropically etched. (See FIG. 2 (f)) Then, the entire surface is 70 nm to 150 nm by a CVD method in a monosilane atmosphere at a temperature of 600 ° C. to 650 ° C.
Of polycrystalline silicon film 209 is deposited, and ions of BF ₂ which is a P-type impurity or As (arsenic) and P (phosphorus) ions which are N-type impurities have an energy of 30 keV to 120 keV.
Implantation is performed under the conditions of keV and dose of 1 × 10 ¹⁴ cm ⁻² or more to form a high concentration impurity layer. (See FIG. 2G) In this manner, the structure of the semiconductor device according to the embodiment of the present invention shown in FIG. 1 can be obtained.

After that, thermal oxidation is performed for 5 minutes to 1 hour in an oxygen atmosphere at 850 ° C. to 1000 ° C.

Conventionally, here, the interlayer film is composed of a polycrystalline silicon film or a silicide film which is an intermediate wiring between the film thickness Td (see FIG. 9) of the silicon oxide film formed on the lower wiring and the lower wiring. Wiring made of polycide and a silicon oxide film Tc formed under the upper wiring (see FIG. 9)
Is thin, oxygen diffuses into the silicon oxide film, reacts with silicon in the second wiring layer to oxidize the second wiring layer, thins the wiring layer, and Stress was born.

However, in the present invention, as the interlayer film, a polycrystalline silicon film or a silicide film which is an intermediate wiring between the film thickness Tb (see FIG. 1) of the silicon oxide film formed on the lower wiring and the lower wiring is used. Since the wiring made of polycide and the silicon oxide film Ta (see FIG. 1) formed under the upper wiring are thick, oxygen diffuses into the silicon oxide film and takes a long time to reach the wiring. It is difficult to react with the silicon in the wiring layer. Therefore, it is difficult for the second wiring layer to be thinned, stress of the wiring film is less likely to occur, and stress in the wiring and its surroundings can be reduced.

Now, description will be given in order of steps based on the embodiment of the present invention shown in FIG.

Here, 401 is a silicon substrate, and 4
02, 404 and 408 are silicon oxide films,
3, 405 and 409 are polycrystalline silicon films, and 406
Is Mo (molybdenum), and 407 is a silicon nitride film.

First, a thermal oxide film or a silicon oxide film 402 is formed on a silicon substrate 401 by a CVD method. (See FIG. 4 (a)) Next, by CVD, about 100 n is deposited on the entire surface of the silicon substrate in a monosilane atmosphere at a temperature of 600 ° C. to 650 ° C.
m to 500 nm of polycrystalline silicon film is deposited,
P (phosphorus) ions are diffused in the polycrystalline silicon film by heat treatment using Cl ₃ at about 900 ° C. for several tens of minutes. Alternatively, BF ₂ ions that are P-type impurities or As (arsenic) and P (phosphorus) ions that are N-type impurities have an energy of 30 keV to 120 keV and a dose amount of 1 × 1.
Implantation is performed under the condition of 0 ¹⁴ cm ^-2 or more to form a high concentration impurity layer.

Then, after patterning by the photo-etching method, etching is performed using a mixed gas of Freon 123 and O ₂ and SF ₆ under a pressure of several mTorr to form a first wiring 403. (See FIG. 4B.) Next, a silicon oxide film 404 of 100 nm to 200 nm is deposited by the CVD method, patterning is performed by the photo-etching method, and then the silicon oxide film is selectively etched. (See FIG. 4C) Next, thermal oxidation is performed for 5 minutes to 1 hour in an oxygen atmosphere diluted with Ar (argon) or N _{2 at} a temperature of 900 ° C. to 1000 ° C. to 50% or less, or by a CVD method. ,
A silicon oxide film of 10 nm to 30 nm is formed.

Then, a temperature of 600 ° C.
The polycrystalline silicon film 40 having a thickness of about 100 nm to 300 nm is formed on the entire surface of the semiconductor substrate in a monosilane atmosphere at 650 ° C.
5 was deposited and POCl ₃ was used to form a number 1 at around 900 ° C.
P (phosphorus) in the polycrystalline silicon film by heat treatment for 0 minutes
Diffuse ions. Alternatively, BF ₂ which is a P-type impurity
Ions or As (arsenic), which is an N-type impurity, P
(Phosphorus) ions with an energy of 30 keV to 120 keV,
Implantation is performed under the condition of a dose amount of 1 × 10 ¹⁴ cm ⁻² or more to form a high concentration impurity layer.

Further, Mo (molybdenum) or, on the polycrystalline silicon film, is formed by the CVD method or the sputtering method.
Mo 406 containing Si is deposited to a thickness of 50 nm to 200 nm. Then, after patterning by the photo-etching method, using a mixed gas of Freon 123 and O ₂ and SF ₆ ,
Etching is performed under a pressure of several mTorr to form a second wiring. (See FIG. 4D) Next, a silicon nitride film 407 is deposited to 50 nm to 150 nm on the entire surface of the silicon substrate by the CVD method. (Fig. 4
Then, a silicon oxide film 408 having a thickness of about 100 nm is deposited by the CVD method. (See FIG. 4 (f)) Next, by a CVD method in a monosilane atmosphere at a temperature of 600 ° C. to 650 ° C., 70 nm to 1 on the entire surface of the semiconductor substrate.
A 50 nm polycrystalline silicon film 409 is deposited, and BF ₂ ions which are P-type impurities or As (arsenic) and P (phosphorus) ions which are N-type impurities have an energy of 30 keV.
Implantation is performed under conditions of 120 keV and a dose of 1 × 10 ¹⁴ cm ^-2 or more to form a high concentration impurity layer. (Fig. 4
(See (g)) Thus, the structure of the semiconductor device according to the embodiment of the present invention shown in FIG. 3 can be obtained.

Then, thermal oxidation is performed for 5 minutes to 1 hour in an oxygen atmosphere at 850 ° C. to 1000 ° C.

Conventionally, since the silicon oxide film alone formed on the wiring made of polycide composed of a polycrystalline silicon film and a silicide film is used as the interlayer film here, the subsequent heat treatment in an oxygen atmosphere causes oxygen to be generated. Diffused into the silicon oxide film and reacted with silicon in the wiring layer to oxidize the wiring layer, thin the wiring layer, and generate stress in the wiring and its surroundings.

However, in the present invention, a polycrystalline silicon film,
Since the silicon nitride film is formed as the interlayer film formed on the wiring made of polycide made of the silicide film, oxygen is prevented from diffusing into the silicon oxide film and reaching the wiring. Therefore, oxidation of the second wiring layer does not occur, and it is difficult for the second wiring layer to be thinned, and the stress on the wiring and its periphery can be reduced.

Now, description will be given in order of steps based on the embodiment of the present invention shown in FIG. Here, 601 is a silicon substrate, 602, 604, 607 and 609 are silicon oxide films, 603, 605 and 610 are polycrystalline silicon films, 606 is Mo (molybdenum), 608.
Is an oxynitride film.

First, a thermal oxide film or a silicon oxide film 602 is formed on the silicon substrate 601 by the CVD method. (See FIG. 6 (a)) Next, by CVD, about 100 n is formed on the entire surface of the silicon substrate in a monosilane atmosphere at a temperature of 600 ° C. to 650 ° C.
A polycrystalline silicon film 603 having a thickness of m to 500 nm is deposited, and P (phosphorus) ions are diffused in the polycrystalline silicon film by heat treatment using POCl ₃ at about 900 ° C. for several tens of minutes. Alternatively, BF ₂ ions that are P-type impurities or As (arsenic) and P (phosphorus) ions that are N-type impurities have an energy of 30 keV to 120 keV and a dose amount of 1
Implantation is performed under the condition of × 10 ¹⁴ cm ^-2 or more to form a high concentration impurity layer.

Then, after patterning by the photo-etching method, etching is performed under a pressure of several mTorr using a mixed gas of Freon 123 and O ₂ and SF ₆ to form a first wiring. (See FIG. 6B.) Next, a 100 nm to 200 nm silicon oxide film 604 is deposited by the CVD method, patterned by the photolithography method, and then the silicon oxide film is selectively etched. (See FIG. 6C) Next, thermal oxidation is performed for 5 minutes to 1 hour at a temperature of 900 ° C. to 1000 ° C. in an oxygen atmosphere diluted with Ar (argon) or N ₂ to 50% or less, and 10 nm to 10 nm 30n
m silicon oxide film is formed.

Then, a temperature of 600 ° C.
A polycrystalline silicon film 60 of about 100 nm to 300 nm is formed on the entire surface of the semiconductor substrate in a monosilane atmosphere at 650 ° C.
5 was deposited and POCl ₃ was used to form a number 1 at around 900 ° C.
P (phosphorus) in the polycrystalline silicon film by heat treatment for 0 minutes
Diffuse ions. Alternatively, BF ₂ which is a P-type impurity
Ions or As (arsenic), which is an N-type impurity, P
(Phosphorus) ions with an energy of 30 keV to 120 keV,
Implantation is performed under the condition of a dose amount of 1 × 10 ¹⁴ cm ⁻² or more to form a high concentration impurity layer.

Further, Mo (molybdenum) or Mo containing 606 containing Si is deposited to 50 nm to 200 nm on the polycrystalline silicon film 605 by the CVD method or the sputtering method.
accumulate.

Then, after patterning by the photo-etching method, etching is performed under a pressure of several mTorr using a mixed gas of Freon 123 and O ₂ and SF ₆ to form a second wiring. (See FIG. 6D.) Then, a silicon oxide film 607 of 20 nm to 50 nm is deposited by thermal oxidation or a CVD method in an oxygen atmosphere at about 900 ° C. (See FIG. 6E) Next, in an NH ₃ atmosphere at a temperature of 950 ° C. to 1100 ° C., 5
Oxynitride film 60 after heat treatment for 1 minute to 1 minute
8 is formed. (See FIG. 6F) Then, a silicon oxide film 609 of about 100 nm is deposited by the CVD method. (See FIG. 6 (g)) Next, by a CVD method, in a monosilane atmosphere at a temperature of 600 ° C. to 650 ° C., the entire surface of the semiconductor substrate is 70 nm to 1 nm.
A 50 nm polycrystalline silicon film 610 is deposited, and BF ₂ ions which are P-type impurities or As (arsenic) and P (phosphorus) ions which are N-type impurities have an energy of 30 keV.
Implantation is performed under conditions of 120 keV and a dose of 1 × 10 ¹⁴ cm ^-2 or more to form a high concentration impurity layer. (Fig. 6
(H)) In this way, the structure of the semiconductor device according to the embodiment of the present invention shown in FIG. 5 can be obtained.

Then, thermal oxidation is performed for 5 minutes to 1 hour in an oxygen atmosphere at 850 ° C. to 1000 ° C.

Conventionally, since the silicon oxide film alone formed on the wiring made of polycide composed of a polycrystalline silicon film and a silicide film is used as the interlayer film here, the subsequent heat treatment in an oxygen atmosphere results in oxygen. Diffused into the silicon oxide film and reacted with silicon in the wiring layer to oxidize the wiring layer, thin the wiring layer, and generate stress in the wiring and its surroundings.

However, in the present invention, the polycrystalline silicon film,
Since the oxynitride film is formed as the interlayer film formed on the wiring made of polycide made of the silicide film, oxygen is prevented from diffusing into the silicon oxide film and reaching the wiring. Therefore, oxidation of the second wiring layer does not occur, and it is difficult for the second wiring layer to be thinned, and the stress on the wiring and its periphery can be reduced.

Although FIG. 6 shows an example in which the heat treatment for forming the oxynitride film is performed in an NH ₃ atmosphere, the temperature is from 850 ° C. to 1 in an N ₂ O atmosphere.
By performing heat treatment at 000 ° C. for 5 minutes to 1 hour to form an oxynitride film, the structure of the semiconductor device according to the embodiment of the present invention shown in FIG. 5 can be obtained. In this case, NH ₃
Since the treatment can be performed at a temperature lower than that in the atmosphere, the MIS transistor is less affected.

The NH ₃ atmosphere and the N ₂ O atmosphere are N
₂ or may be a mixed gas diluted with an inert gas such as Ar (argon), the same effect can be obtained. Now, description will be given in order of steps based on the embodiment of the present invention shown in FIG. Here, 801 is a silicon substrate, 802, 804, 807, 810 are silicon oxide films, 803, 805, 811 are polycrystalline silicon, 806Mo (molybdenum), 808 is nitrogen ion, 809 is an oxynitride film.

First, a thermal oxide film or a silicon oxide film 802 is formed on the silicon substrate 801 by the CVD method. (See FIG. 8A) Next, by CVD, about 100 n is formed on the entire surface of the silicon substrate in a monosilane atmosphere at a temperature of 600 ° C. to 650 ° C.
A polycrystalline silicon film 803 having a thickness of m to 500 nm is deposited, and P (phosphorus) ions are diffused in the polycrystalline silicon film by heat treatment using POCl ₃ at about 900 ° C. for several tens of minutes. Alternatively, BF ₂ ions that are P-type impurities or As (arsenic) and P (phosphorus) ions that are N-type impurities have an energy of 30 keV to 120 keV and a dose amount of 1
Implantation is performed under the condition of × 10 ¹⁴ cm ^-2 or more to form a high concentration impurity layer.

After patterning by the photo-etching method, etching is performed under a pressure of several mTorr using a mixed gas of Freon 123 and O ₂ and SF ₆ to form a first wiring. (See FIG. 8B) Next, a silicon oxide film 804 of 100 nm to 200 nm is deposited by the CVD method, and after patterning by the photo-etching method, the silicon oxide film is selectively etched. (See FIG. 8C) Next, thermal oxidation is performed for 5 minutes to 1 hour at a temperature of 900 ° C. to 1000 ° C. in an oxygen atmosphere diluted with Ar (argon) or N ₂ to 50% or less, and 10 nm to 10 nm 30n
m silicon oxide film is formed.

Then, a temperature of 600 ° C.
A polycrystalline silicon film 80 having a thickness of about 100 nm to 300 nm is formed on the entire surface of the semiconductor substrate in a monosilane atmosphere at 650 ° C.
5 was deposited and POCl ₃ was used to form a number 1 at around 900 ° C.
P (phosphorus) in the polycrystalline silicon film by heat treatment for 0 minutes
Diffuse ions. Alternatively, BF ₂ which is a P-type impurity
Ions or As (arsenic), which is an N-type impurity, P
(Phosphorus) ions with an energy of 30 keV to 120 keV,
Implantation is performed under the condition of a dose amount of 1 × 10 ¹⁴ cm ⁻² or more to form a high concentration impurity layer.

Further, Mo (molybdenum) or, on the polycrystalline silicon film by the CVD method or the sputtering method,
Mo806 containing Si is deposited to a thickness of 50 nm to 200 nm. Then, after patterning by the photo-etching method, using a mixed gas of Freon 123 and O ₂ and SF ₆ ,
Etching is performed under a pressure of several mTorr to form a second wiring. (See FIG. 8D) Then, a silicon oxide film 807 of 50 nm to 150 nm is deposited by the CVD method. (See FIG. 8E) Next, energy 30 keV to 80 keV, dose 1
Nitrogen ions 808 are implanted under the condition of × 10 ¹⁴ cm ^-2 or more, and the temperature is about 900 ° C. in an N ₂ atmosphere for 5 minutes to 3 minutes.
An oxynitride film 809 is formed by performing heat treatment for 0 minutes. (See FIG. 8F) Then, a silicon oxide film 810 of about 50 nm is deposited by the CVD method. (See FIG. 8 (g)) Next, according to the CVD method, 70 nm to 1 nm is formed on the entire surface of the semiconductor substrate in a monosilane atmosphere at a temperature of 600 ° C. to 650 ° C.
A polycrystalline silicon film 811 having a thickness of 50 nm is deposited, and BF ₂ ions which are P-type impurities or As (arsenic) and P (phosphorus) ions which are N-type impurities have an energy of 30 keV.
Implantation is performed under the conditions of 120 keV and a dose of 1 × 10 ¹⁴ cm ⁻² or more to form a high concentration impurity layer. (Fig. 8
(See (h)) In this way, the structure of the semiconductor device according to the embodiment of the present invention shown in FIG. 7 can be obtained.

Then, thermal oxidation is performed for 5 minutes to 1 hour in an oxygen atmosphere at 850 ° C. to 1000 ° C.

As described with reference to FIG. 6, conventionally, stress is generated in the wiring and its surroundings.

However, in the present invention, a polycrystalline silicon film,
Since the oxynitride film is formed as the interlayer film formed on the wiring made of polycide made of the silicide film, oxygen is prevented from diffusing into the silicon oxide film and reaching the wiring. Therefore, oxidation of the second wiring layer does not occur, and it is difficult for the second wiring layer to be thinned, and the stress on the wiring and its periphery can be reduced.

The semiconductor device thus formed, and
In the manufacturing method, it is possible to prevent the wiring from being oxidized by the heat treatment in the oxygen atmosphere after forming the polycide wiring formed of the polycrystalline silicon film and the silicide film.

As a result, it is possible to reduce the thickness of the wiring due to the oxidation of the wiring and to reduce the stress on the wiring and the insulating film around the wiring.

Therefore, it becomes possible to reduce the current leakage from the wiring and to reduce the breakdown of the insulating film around the wiring.

[0051]

As described above, according to the semiconductor device and the method of manufacturing the same of the present invention, it is possible to reduce the current leakage from the wiring and the breakdown of the insulating film around the wiring. As a semiconductor device, a device with high yield and high reliability can be provided.

[Brief description of drawings]

FIG. 1 is a cross-sectional view of a semiconductor device according to an embodiment of the present invention.

FIG. 2 is a cross-sectional view of the method for manufacturing the semiconductor device according to the exemplary embodiment of the present invention.

FIG. 3 is a sectional view of a semiconductor device according to an embodiment of the present invention.

FIG. 4 is a cross-sectional view along the method for manufacturing a semiconductor device according to the embodiment of the present invention.

FIG. 5 is a sectional view of a semiconductor device according to an embodiment of the present invention.

FIG. 6 is a cross-sectional view of the method for manufacturing the semiconductor device according to the exemplary embodiment of the present invention.

FIG. 7 is a sectional view of a semiconductor device according to an example of the present invention.

FIG. 8 is a sectional view taken along the method for manufacturing a semiconductor device according to the embodiment of the present invention.

FIG. 9 is a sectional view of a conventional semiconductor device.

[Explanation of symbols]

 101, 201 Silicon substrate 102, 202 Silicon oxide film 103, 203 Polycrystalline silicon film 104, 204 Silicon oxide film 105, 205 Polycrystalline silicon film 106, 206 Mo (molybdenum) 107 Polycrystalline silicon film 207 Silicon oxide film 208 Resist 209 Polycrystalline silicon film 301, 401 Silicon substrate 302, 402 Silicon oxide film 303, 403 Polycrystalline silicon film 304, 404 Silicon oxide film 305, 405 Polycrystalline silicon film 306, 406 Mo (molybdenum) 307, 407 Silicon nitride film 308, 408 Silicon oxide film 309, 409 Polycrystalline silicon film 501, 601 Silicon substrate 502, 602 Silicon oxide film 503, 603 Polycrystalline silicon film 504, 604 Silicon oxide film 505, 60 5 Polycrystalline Silicon Films 506 and 606 Mo (Molybdenum) 507 and 607 Silicon Oxide Films 508 and 608 Oxynitride Films 509 and 609 Silicon Oxide Films 510 and 610 Polycrystalline Silicon Films 701 and 801 Silicon Substrates 702 and 802 Silicon Oxide Films 703 803 polycrystalline silicon film 704, 804 silicon oxide film 705, 805 polycrystalline silicon film 706, 806 Mo (molybdenum) 707, 807 silicon oxide film 708, 809 oxynitride film 808 nitrogen ion 709, 810 silicon oxide film 710, 811 polycrystalline silicon film 901 silicon substrate 902 silicon oxide film 903 polycrystalline silicon film 904 silicon oxide film 905 polycrystalline silicon film 906 Mo (molybdenum) 907 polycrystalline silicon film

Claims (10)

[Claims] 1. A semiconductor device comprising at least three or more layers of wiring, comprising a polycide composed of a first wiring and a polycrystalline silicon film or a silicide film formed under the first wiring. The film thickness of the first interlayer insulating film between the two wirings is greater than the film thickness of the second interlayer insulating film formed between the third wiring formed under the second wiring and the first wiring. A semiconductor device characterized by being thick. 2. A semiconductor device having at least three layers of wiring, a step of forming a first wiring on a semiconductor substrate, and a step of forming a first insulating film on the first wiring. A step of depositing a polycrystalline silicon film on the first insulating film, a step of forming a silicide film on the polycrystalline silicon film, and a step of selectively removing the polycrystalline silicon film and the silicide film, Forming a second wiring;
A step of depositing a second interlayer insulating film on the wiring, a step of selectively reducing the second interlayer insulating film on a region excluding the second wiring, and a step of depositing the second interlayer insulating film on the second interlayer insulating film. A method of manufacturing a semiconductor device, comprising the step of forming a third wiring. 3. A semiconductor device comprising at least three layers of wiring, which is located in the middle and is a polycrystalline silicon film,
A semiconductor device, wherein an interlayer insulating film formed on a wiring made of polycide made of silicide includes a silicon nitride film. 4. A semiconductor device comprising at least three or more layers of wiring, depositing a polycrystalline silicon film on a semiconductor substrate, forming a silicide film on the polycrystalline silicon film, A method of manufacturing a semiconductor device, comprising: a step of selectively removing a polycrystalline silicon film and a silicide film to form a second wiring; and a step of depositing a silicon nitride film on the second wiring. . 5. A semiconductor device having at least three layers of wiring, which is located in the middle and has a polycrystalline silicon film,
An interlayer insulating film formed on the wiring made by made polycide from silicide, x, SiO satisfies y> 0 _x
A semiconductor device comprising N _y . 6. In a semiconductor device having at least three layers of wiring, a step of depositing a polycrystalline silicon film on a semiconductor substrate, a step of forming a silicide film on the polycrystalline silicon film, A step of selectively removing the polycrystalline silicon film and the silicide film to form a second wiring, a step of depositing a silicon oxide film on the second wiring, and then in an atmosphere containing NH _3. A method of manufacturing a semiconductor device, comprising the step of performing heat treatment. 7. The method of manufacturing a semiconductor device according to claim 6, wherein the atmosphere containing NH ₃ is diluted with only NH ₃ , or with N ₂ and an inert gas. 8. In a semiconductor device having at least three layers of wiring, a step of depositing a polycrystalline silicon film on a semiconductor substrate, a step of forming a silicide film on the polycrystalline silicon film, A step of selectively removing the polycrystalline silicon film and the silicide film to form a second wiring, a step of depositing a silicon oxide film on the second wiring, and then an atmosphere containing N ₂ O A method of manufacturing a semiconductor device, comprising the step of performing heat treatment in step 1. 9. The method of manufacturing a semiconductor device according to claim 8, wherein the atmosphere containing N ₂ O is diluted with N ₂ O alone or N ₂ and an inert gas. 10. In a semiconductor device having at least three layers of wirings, a step of depositing a polycrystalline silicon film on a semiconductor substrate, a step of forming a silicide film on the polycrystalline silicon film, A step of selectively removing the polycrystalline silicon film and the silicide film to form a second wiring, a step of depositing a silicon oxide film on the second wiring, and then nitrogen ions in the silicon oxide film. A method of manufacturing a semiconductor device, comprising the step of implanting.