JPH09249972A - Forming method of thin film, semiconductor device and its production - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a semiconductor device having a fine pattern of iridium film by selectively depositing iridium or iridium oxide film on a first area where a first material on a substrate is exposed. SOLUTION: When an iridium film or iridium oxide film is formed by CVD method, a film forming chamber 10 is first evacuated, a substrate 14 is heated by a heater of a susceptor 16, Ar gas with a carrier gas is made to flow to introduce sublimated Ir(DPM)3 (iridium dipivaloylmethane) into the film forming chamber 10. At the same time, H2 gas is introduced through a gas supply tube 18 to react with the Ir(DPM)3 on the substrate 14 to form an iridium film on the substrate 14. Or, oxygen is introduced to form an iridium oxide film. In this method, by controlling the temp. of the substrate 14 to about 400-550 deg.C and the pressure in the film forming chamber 10 to about 0.1-20Torr, a film can be formed only in the exposed part of the base film in the first region of the substrate 14.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to thin film formation, and more particularly to a thin film forming method for forming an iridium thin film and an iridium oxide thin film, a semiconductor device and a method for manufacturing the same.

[0002]

2. Description of the Related Art Iridium thin films are made of SrTiO ₃ , (B
a, Sr) Used as an electrode of a high dielectric material such as TiO ₃ . Conventionally, heat C has been used to form an iridium film or an iridium oxide film in a semiconductor device manufacturing process.
VD (Chemical Vapor Deposition)
Method, plasma CVD method, sputtering method and the like have been used.

In the method of depositing an iridium film or an iridium oxide film by the CVD method, iridium dipivaloylmethane (Iridium dipivalo) is used as an iridium raw material.
ylmethane: hereinafter referred to as Ir (DPM) ₃ ) was used. Since Ir (DPM) ₃ is a powdery solid at room temperature, it needs to be a gas for use in the CVD method. Therefore, Ir (DPM) ₃ was sublimated by the following procedure.

First, powdery Ir (DPM) ₃ is filled in a low vapor pressure raw material container and placed in a constant temperature bath. Then
The temperature inside the thermostatic chamber is raised to the sublimation temperature of Ir (DPM) ₃ , and I
Sublimate r (DPM) ₃ . Subsequently, Ir (DPM) ₃ was bubbled with an inert gas to sublimate Ir (DP
M) ₃ is introduced into the film forming chamber together with an inert gas. Thus, the raw material introduced into the film forming chamber was decomposed and reacted on the substrate heated and held at about 300 to 500 ° C., and the iridium film was deposited on the substrate.

Further, the iridium oxide film is formed of Ir (DP
It was deposited by introducing oxygen gas into the film formation chamber simultaneously with the introduction of M) ₃ . The iridium film or the iridium oxide film thus deposited needs to be processed into a pattern according to the application, but since the iridium film or the iridium oxide film does not generate a reactant having a high vapor pressure, the RIE
It has been difficult to use a patterning method utilizing a reaction such as (Reactive Ion Etching) method.

Therefore, when patterning an iridium film or an iridium oxide film, a so-called ion milling method has been used in which a target is physically processed by impact of ions.

[0007]

However, since it is difficult to process a fine pattern by patterning the iridium film or the iridium oxide film by the above-mentioned conventional ion milling method, it is difficult to process a fine pattern. Was difficult to apply to. From this point of view, selective growth of an iridium film or an iridium oxide film is a desirable technique, but the possibility of selective growth has not been found under conventional film forming conditions.

An object of the present invention is to provide a thin film forming method for selectively growing an iridium film and an iridium oxide film. Another object of the present invention is to provide a semiconductor device having a fine pattern of an iridium film and an iridium oxide film by selectively growing the iridium film and the iridium oxide film, and a manufacturing method thereof.

[0009]

[Means for Solving the Problems] The above-mentioned object is Ir (DP
M) ₃ is a thin film forming method for forming an iridium film or an iridium oxide film by a chemical vapor deposition method using a raw material, wherein the first substance is exposed in the first region and the second substance is exposed in the second region. In the first region on the substrate on which the substance is exposed,
This is achieved by a thin film forming method characterized by selectively depositing an iridium film or an iridium oxide film. Since the iridium film or the iridium oxide film is selectively formed in this manner, it is not necessary to pattern the iridium film or the iridium oxide film by the ion milling method, and the iridium film or the iridium oxide film having a fine pattern can be easily formed. be able to.

In the above thin film forming method, it is desirable that the first substance is Ti or TiN and the second substance is silicon oxide. If the deposition target substrate is configured in this way, the iridium film or the iridium oxide film can be deposited only on Ti or TiN. Further, in the above thin film forming method, when depositing the iridium film, a substrate on which the iridium film is deposited,
It is desirable to set the temperature higher than 400 ° C. and lower than 550 ° C., and set the film forming chamber for forming the iridium film to a pressure higher than 0.1 Torr and lower than 20 Torr. By setting the thin film forming conditions in this way, the iridium film can be selectively grown.

Further, in the above thin film forming method, when depositing the iridium oxide film, the substrate on which the iridium oxide film is deposited is set to a temperature higher than 400 ° C. and lower than 600 ° C. It is desirable to set the film forming chamber for forming the film to a pressure higher than 0.1 Torr and lower than 30 Torr. By setting the thin film forming conditions in this way, the iridium oxide film can be selectively grown.

The present invention can also be achieved by a semiconductor device characterized by having an iridium film or an iridium oxide film formed by the above thin film forming method. If a semiconductor device is formed using such an iridium film or an iridium oxide film, the semiconductor device can be easily miniaturized. Further, in a semiconductor device having a capacitor in which a lower electrode, a dielectric film, and an upper electrode are sequentially stacked, the upper electrode or the lower electrode is an iridium film formed by the above thin film forming method or It is also achieved by a semiconductor device having an iridium oxide film. By configuring the semiconductor device in this way, the patterning process of the iridium film or the iridium oxide film is unnecessary, and a capacitor having a fine pattern can be configured.

Further, according to the above-described thin film forming method, the plug selectively formed in the through hole formed in the base substrate and the iridium non-selectively formed on the base substrate in which the plug is formed are formed. It is also achieved by a semiconductor device having a film or an electrode made of an iridium oxide film. By configuring the semiconductor device in this way, the steps of filling the through holes and forming the electrodes can be simplified.

Further, a barrier layer forming step of forming a barrier layer made of a Ti film or a TiN film in the first region on the base substrate and the thin film forming method described above are used to selectively form an iridium film on the barrier layer. Alternatively, a lower electrode forming step of depositing an iridium oxide film to form a lower electrode, a dielectric film forming step of forming a dielectric film on the lower electrode, and an upper electrode forming an upper electrode on the dielectric film. It is also achieved by a method for manufacturing a semiconductor device, which includes a forming step. By manufacturing the semiconductor device in this manner, patterning of the lower electrode is not required, and the manufacturing process can be simplified. In addition, fine patterns can be formed.

Further, a first thin film forming step of selectively forming a first iridium film or a first iridium oxide film in a predetermined region of the deposition target substrate, and the first selectively formed film. A second thin film forming step of depositing a second iridium film or a second iridium oxide film on the entire surface of the deposition target substrate having the iridium film or the first iridium oxide film. It is also achieved by a method of manufacturing a semiconductor device.

A plug forming step of selectively burying an iridium film or an iridium oxide film in the through hole of the deposition substrate having a silicon oxide film having a through hole formed on the surface thereof by the above thin film forming method. ,
An electrode forming step of non-selectively forming an iridium film or an iridium oxide film on the silicon oxide film in which the plug is embedded in the through hole, and forming an electrode connected to the plug. It is also achieved by a method of manufacturing a characteristic semiconductor device. When the semiconductor device is manufactured in this manner, the through holes can be filled and the electrodes can be continuously formed by simply changing the deposition conditions of the iridium film or the iridium oxide film. Thereby, the manufacturing process of the semiconductor device can be simplified.

[0017]

DETAILED DESCRIPTION OF THE INVENTION A thin film forming method according to a first embodiment of the present invention will be described with reference to FIGS. FIG. 1 is a schematic view of a CVD apparatus used in the thin film forming method according to the present embodiment, and FIG. 2 is a graph showing the deposition condition dependency of the deposition rate when an iridium film is formed on a silicon oxide film,
FIG. 3 is a graph showing the deposition rate dependence of the deposition rate when the iridium film is formed on the TiN film, and FIG. 4 is the deposition rate dependence of the deposition rate when the iridium oxide film is formed on the silicon oxide film. It is a graph which shows.

The inventor of the present invention has conducted extensive studies on the growth conditions of the iridium film and the iridium oxide film, and as a result, newly found that the selective growth by the CVD method is possible under predetermined conditions. The present invention is based on the above phenomenon found by the inventor of the present application. The details will be described below.

First, the CVD apparatus used in the thin film forming method according to the present embodiment will be explained with reference to FIG. A vacuum pump 12 is connected to the film forming chamber 10 for growing a thin film so that the inside of the film forming chamber 10 can be depressurized. Inside the film forming chamber 10, a susceptor 16 for mounting a substrate 14 on which a film is to be formed is provided. A lamp heater 17 that heats the substrate 14 during film formation is provided on the susceptor 16.

The film forming chamber 10 is further connected to a gas supply pipe 18 for introducing H ₂ (hydrogen) gas or O ₂ (oxygen) gas and a gas supply pipe 20 for introducing a gas containing an organometallic raw material. There is. A shower head 22 is formed in the film forming chamber 10 so that the gas introduced into the film forming chamber 10 in this manner is uniformly supplied into the film forming chamber 10.

The other side of the gas supply pipe 20 is connected to a gas control device 24 for heating and sublimating the metal compound and introducing it into the film forming chamber 10 together with the carrier gas. The gas control device 24 includes a general formula,

[0022]

Embedded image A raw material container 26 filled with Ir (DPM) _3, which is a metal raw material, is provided. Ir (DPM) ₃ is an orange powder at room temperature, which is sublimed and used for film formation. Therefore, the raw material container 26 is
It is placed inside a constant temperature bath 28 for heating the raw material container 26 to a temperature of about 150 to 200 ° C.

A gas supply pipe 30 for introducing Ar gas as a carrier gas is further connected to the raw material container 26. By introducing Ar gas into the raw material container 26 from the gas supply pipe 30, the gas is sublimated together with the Ar gas. Ir done
(DPM) ₃ can be introduced into the film forming chamber 10. Further, a heater 32 is provided in the film forming chamber 10, the gas supply pipes 18 and 20, and the pipe between the film forming chamber 10 and the raw material container 26 in order to suppress condensation of gas in the pipe. Is kept at 150 to 210 ° C., which is about 5 ° C. higher than the sublimation temperature of Ir (DPM) ₃ .

When the iridium film or the iridium oxide film is formed by the CVD apparatus shown in FIG. 1, the film is formed by the following procedure, for example. First, after depressurizing the inside of the film forming chamber 10 by the vacuum pump 12, the substrate 14 on which the iridium film is deposited is heated by the heater of the susceptor 16. Next, Ar gas as a carrier gas is caused to flow at a predetermined flow rate and introduced into the film forming chamber 10 together with sublimated Ir (DPM) ₃ . At the same time, by introducing H ₂ gas from the gas supply pipe 18, Ir (DPM) ₃ and H ₂ gas react with each other on the substrate 14 to deposit an iridium thin film on the substrate 14.

When depositing the iridium oxide thin film on the substrate 14, O ₂ gas is introduced into the film forming chamber 10 instead of H ₂ gas, and Ir (DPM) ₃ and O ₂ gas are deposited on the substrate 14. You can react with. Next, a thin film forming method for selectively depositing an iridium film and an iridium oxide film by using the above CVD apparatus will be described.

FIG. 2 shows a film thickness of 200 nm on a silicon substrate.
Dependence of deposition rate on the substrate temperature when the iridium film is deposited on the underlying substrate on which the silicon oxide film of FIG.
(A)), and the deposition rate pressure dependency of the deposition rate (see FIG. 2).
(B)). As shown in the figure, the deposition rate of the iridium film depends on the substrate temperature and the pressure of the film forming chamber, but a point to be particularly noted in this figure is that when a specific film forming chamber pressure is set at a specific substrate temperature, The condition is that the deposition rate becomes almost zero.

That is, the substrate temperature is set to 450 ° C.,
When the pressure in the film forming chamber is 1 Torr, the substrate temperature is 500
When the temperature is set to 0 ° C. and the pressure in the film forming chamber is 10 Torr, the deposition rate is almost zero. Therefore, under this film forming condition, the iridium film is not deposited on the silicon oxide film. The results of FIG. 2 are summarized in Table 1.

[0028]

[Table 1] In the table, ◯ indicates conditions under which the iridium thin film was not deposited, and x indicates conditions under which the iridium thin film was deposited. As inferred from Table 1, the condition that the iridium film is not deposited is established in the relation between the substrate temperature and the pressure of the film forming chamber, and within that range, the higher the substrate temperature, the higher the pressure of the film forming chamber becomes. It needs to be high.

When the substrate temperature is lower than 400 ° C.,
Alternatively, when the temperature was higher than 550 ° C., no condition was found in which the iridium thin film was not deposited. Similarly, when the pressure in the film forming chamber is lower than 0.1 Torr, or 20 Torr
At higher temperatures, no conditions were found in which no iridium thin film was deposited. The same measurement was performed using TiN as the base
The results obtained for the case of the (titanium nitride) film are shown in FIG. FIG. 3A shows the result of measuring the substrate temperature dependency with the pressure of the film forming chamber kept constant at 10 Torr, and FIG. 3B shows the result of measuring the pressure dependency of the film forming chamber with the substrate temperature kept constant at 500 ° C. Shows.

As shown in the figure, the deposition rate of the iridium film depends on the substrate temperature and the pressure of the film forming chamber. However, when the underlying layer is a silicon oxide film, the iridium film is not deposited, that is, the substrate temperature. It can be seen that the iridium film is deposited even when the pressure is 500 ° C. and the pressure in the film forming chamber is 10 Torr. Therefore, if the iridium film is deposited under a predetermined condition on the substrate having the region where the silicon oxide film is exposed and the region where the TiN film is exposed, the iridium film can be selectively deposited only on the TiN film. .

Next, the results of similar measurements performed on the iridium oxide film are shown. FIG. 4 shows 20 on a silicon substrate.
When an iridium oxide film is deposited on a base substrate on which a 0 nm silicon oxide film is formed, the deposition rate depends on the substrate temperature (FIG. 4A) and the deposition chamber pressure (FIG. 4).
(B)). As shown, in the case of the iridium oxide thin film, as in the case of the iridium film,
It can be seen that there is a condition that the deposition rate becomes substantially zero when the pressure is set to a specific film forming chamber pressure at a specific substrate temperature.

That is, the substrate temperature is set to 450 ° C.,
When the pressure in the film forming chamber is 1 Torr, the substrate temperature is 500
If the pressure in the deposition chamber is set to 10 Torr,
The substrate temperature is set to 550 ° C. and the pressure in the film forming chamber is 20To.
The deposition rate is almost zero when rr is set. Therefore, under this film forming condition, the iridium oxide film is not deposited on the silicon oxide film.

The results of FIG. 4 are summarized in Table 2.

[0034]

[Table 2] In the table, ◯ indicates conditions under which the iridium oxide thin film was not deposited, and X indicates conditions under which the iridium oxide thin film was deposited. Similar to the case of the iridium film, the condition that the iridium oxide film is not deposited is established in the relation between the substrate temperature and the pressure of the film forming chamber. In that range, the higher the substrate temperature is, the higher the pressure of the film forming chamber is. There is a need to.

When the substrate temperature is lower than 400 ° C.,
Or, when the temperature was higher than 600 ° C., the condition that the iridium thin film was not deposited was not found. Similarly, when the pressure in the film forming chamber is lower than 0.1 Torr, or 30 Torr
No higher iridium oxide thin film deposition conditions were found above. Iridium oxide film is TiN
When deposited on the film, the condition under which the iridium oxide film was not formed could not be found, as in the case of the iridium film.

Therefore, if an iridium oxide film is deposited under a predetermined condition on a substrate having a region where the silicon oxide film is exposed and a region where the TiN film is exposed, the iridium oxide film is selectively formed only on the TiN film. Can be deposited.
Although the mechanism by which the iridium film or the iridium oxide film can be selectively grown is not clear as described above, under the condition that the iridium film or the iridium oxide film is not deposited on the silicon oxide film, Ir (D
Although PM) ₃ is adsorbed on the surface of the silicon oxide film, it is considered that the film was not deposited on the substrate because it was evaporated without being decomposed.

On the contrary, an iridium film /
Under the condition that the iridium oxide film is deposited, the absorbed Ir
Since (DPM) ₃ has a sufficient substrate temperature to decompose on the substrate, or has not been evaporated because of the low substrate temperature,
It is considered that the iridium film / iridium oxide film was deposited on the substrate. Further, the range of conditions under which selective growth is possible is wider in the case of depositing an iridium oxide film than in the case of depositing an iridium film, because the O ₂ gas introduced at the time of film formation is Ir (DPM) ₃ It is considered to promote evaporation.

As described above, according to this embodiment, Ir
When depositing an iridium film or an iridium oxide film by a CVD method using (DPM) ₃ as a source gas, by setting the relationship between the temperature of the substrate on which the film is deposited and the pressure in the film forming chamber to a predetermined condition An iridium film and an iridium oxide film can be selectively deposited. In the above embodiment, the TiN film is used as the base material capable of forming the iridium film or the iridium oxide film under the condition that the iridium film or the iridium oxide film is selectively grown. Since only the iridium film and the iridium oxide film are not deposited, the selective growth can be realized by using other materials. For example, a Ti film may be used as the base material, or an iridium oxide film or an iridium film may be used.

By introducing H ₂ gas during the formation of the iridium film, it is possible to form an iridium film having excellent orientation. This is Japanese Patent Application No. 7 by the same applicant.
This is because the concentration of carbon contained in the film can be reduced by introducing H ₂ gas as described in the specification of No. 67816. In order to obtain such an effect, it is desirable that the concentration of H ₂ gas introduced into the film forming chamber is 30% or less of the total gas concentration.

When forming an iridium oxide film, it is desirable to set the concentration of O ₂ gas introduced into the film forming chamber to about 50% of the total gas concentration. Next, the semiconductor device and the method for fabricating the same according to the second embodiment of the present invention will be explained with reference to FIGS. FIG. 5 is a view showing the structure of the semiconductor device according to the present embodiment, FIGS. 6 and 7 are process cross-sectional views showing the method for manufacturing the semiconductor device according to the present embodiment,
8 to 10 are views showing the structure of the semiconductor device according to the modification of the present embodiment.

In this embodiment, as an example of applying the iridium oxide thin film selectively formed by the thin film manufacturing method according to the first embodiment to a semiconductor device, a structure and a manufacturing method of a DRAM having the iridium thin film as a lower electrode of a capacitor will be described. Show. First, the structure of the semiconductor device according to the present embodiment will be explained with reference to FIG. A transfer transistor Tr including a source diffusion layer 44, a drain diffusion layer 46, and a gate electrode 48 is formed in an element region on the silicon substrate 40 defined by the element isolation film 42. A wiring layer 50 forming a bit line is formed on the drain diffusion layer 46. On the silicon substrate 40 with the transfer transistor Tr formed on, an interlayer insulating film 54 having a through hole 52 formed on the source diffusion layer 44 is formed.

A lower electrode 58 made of an iridium film, a capacitor dielectric film 60 made of SrTiO ₃ and a Pt ( A capacitor C having an upper electrode 62 made of platinum) is formed. The lower electrode 58 is connected to the source diffusion layer 44 via the barrier layer 56 and the conductive plug 64 embedded in the through hole 52. An interlayer insulating film 66 is formed on the capacitor, and a wiring layer 68 is formed on the interlayer insulating film 66.

In this way, a DRAM composed of one transistor and one capacitor is constructed. Next, the method for fabricating the semiconductor device according to the present embodiment will be explained with reference to FIGS. First, a normal MO film is formed on the silicon substrate 40 whose element region is defined by the element isolation film 42.
The source diffusion layer 44 is formed by the manufacturing process of the S transistor.
Then, the transfer transistor Tr having the drain diffusion layer 46 and the gate electrode 48 is formed (FIG. 6A).

Next, an insulating film 49 covering the gate electrode 48.
Then, the wiring layer 50 connected to the drain diffusion layer 46 is formed. The wiring layer 50 extends in a direction orthogonal to the gate electrode 48 and constitutes a bit line (not shown). Then, a silicon oxide film to be the interlayer insulating film 54 is formed by the thermal CVD method, and the through hole 52 opened on the source diffusion layer 44 is formed (FIG. 6B).

After that, a polycrystalline silicon film is deposited on the entire surface and etched back to form a plug 64 embedded in the through hole 52. Next, T which becomes the barrier layer 56
An i film and a TiN film are continuously formed by a sputtering method and patterned by a usual lithography process and etching process. Thus, the barrier layer 56 is formed (FIG. 6C).

Subsequently, the iridium film is selectively grown by using the thin film forming method according to the first embodiment. At this time, the interlayer insulating film 54 made of a silicon oxide film and the barrier layer 56 made of a TiN film are exposed on the surface of the silicon substrate 40. Therefore, the iridium film is not deposited on the interlayer insulating film 54 but only on the barrier layer 56. Thus, the lower electrode 58 made of the iridium film is formed (FIG. 7A).

When the lower electrode 58 is formed by selective growth of the iridium film in this manner, it is not necessary to pattern the iridium film by the ion milling method, and therefore the fine processing of the lower electrode 58 becomes possible. Then, a SrTiO ₃ film is deposited by the sputtering method and patterned by the ion milling method to form a capacitor dielectric film 60 made of the SrTiO ₃ film.

Next, a Pt film is deposited by the sputtering method and patterned by the ion milling method to form the upper electrode 62 of the Pt film. Thus, the lower electrode 58
Then, the capacitor C including the capacitor dielectric film 60 and the upper electrode 62 is formed. Then, a silicon oxide film is deposited by a thermal CVD method to form an interlayer insulating film 66.

Thereafter, the wiring layer 68 connected to the upper electrode 62 via the interlayer insulating film 64 is formed. Thus 1
A DRAM composed of transistors and one capacitor can be formed (FIG. 7B). As described above, in the method of manufacturing the semiconductor device according to the present embodiment, the iridium film to be the lower electrode 58 is deposited by selective growth, so that there is no need to process it by ion milling. As a result, the lower electrode 58 having a fine pattern can be formed without sacrificing the device size.

Since the lower electrode 58 is formed by selective growth using the CVD method, it is formed so as to cover the barrier layer 56. As a result, it is possible to prevent the barrier layer 56 from being oxidized when the capacitor dielectric film 60 is deposited. This can prevent the barrier layer 56 from having a high resistance. Although the iridium film is used as the lower electrode in the above embodiment, an iridium oxide film formed by selective growth may be used.

As shown in FIG. 8, the iridium film 7
The lower electrode 58 may be formed by continuously selectively growing 0 and the iridium oxide film 72. Further, as shown in FIG. 9, the lower electrode 5 is formed by continuously selectively growing the iridium oxide film 72 and the iridium film 74.
8 may be formed. Furthermore, as shown in FIG. 10, the lower electrode 58 may be formed by continuously and selectively growing an iridium film 70, an iridium oxide film 72, and an iridium film 74.

Next, the semiconductor device and the method for fabricating the same according to the third embodiment of the present invention will be explained with reference to FIGS. 11 is a diagram showing the structure of the semiconductor device according to the present embodiment, FIGS. 12 and 13 are process cross-sectional views showing the method for manufacturing the semiconductor device according to the present embodiment, and FIGS. 14 to 17 are semiconductors according to modifications of the present embodiment. It is a schematic sectional drawing which shows the structure of an apparatus.

In the present embodiment, in the process of growing an iridium film or an iridium oxide film, a semiconductor device is manufactured by combining the selective growth technique according to the first embodiment and a film formation technique that does not rely on selective growth. There are features. That is, in the semiconductor device according to the present embodiment, in the semiconductor device according to the second embodiment shown in FIG.
The plug 64 is formed of the iridium film selectively grown in 2 and the lower electrode 58 is formed of the iridium film grown without selective growth (FIG. 11).

Next, the method for fabricating the semiconductor device according to the present embodiment will be explained with reference to FIGS. First, FIG.
Similar to the method of manufacturing the semiconductor device according to the second embodiment shown in (a) and (b), the transfer transistor Tr is formed, and then the wiring layer 50 is formed. Next, Ti film and T
An iN film is continuously formed by a sputtering method and patterned by a usual lithography process and etching process. Thus, the barrier layer 56 is formed on the source diffusion layer 44.

Subsequently, the interlayer insulating film 5 is formed by the thermal CVD method.
A silicon oxide film to be 4 is formed and a through hole 52 opened on the source diffusion layer 44 is formed. The barrier layer 56 is exposed at the bottom of the through hole 52 (FIG. 12A). The barrier layer 56 may be formed after forming the interlayer insulating film 54. For example, through hole 5
After opening 2, the Ti film and the TiN film are deposited on the entire surface by the sputtering method, and the Ti film and the TiN film on the interlayer insulating film 54 and the TiN film are deposited.
By removing only the film, the barrier layer 56 can be left on the inner wall and the bottom of the through hole 52 (FIG. 1).
4). The Ti film and the TiN film on the interlayer insulating film 54 are formed, for example, by CMP (Chemical Mechanical Polishing: Chemical Mechanical Polishing).
It can be easily removed by the Polishing method.

Thereafter, the iridium film is selectively grown by using the thin film forming method according to the first embodiment. At this time, since the TiN film on which the iridium film can grow is exposed only at the bottom of the through hole 52, the growth of the iridium film occurs only inside the through hole 52. Thus, the plug 64 embedded inside the through hole 52 is formed (FIG. 12B).

Then, the conditions for forming the iridium film are changed to conditions under which selective growth does not occur, and the film formation for the iridium film is continued. As a result, the iridium film 65 connected to the plug 64 is formed (FIG. 12C). When the pattern of the lower electrode 58 is fine and the patterning by the ion milling method is not appropriate, the formation of the iridium film is once interrupted at the stage when the plug 64 is formed, and the lower electrode 58 is processed into the shape of the lower electrode 58. The TiN film 67 may be deposited on the interlayer insulating film 54. By doing this, TiN
An iridium film can be selectively grown on the film 67, and a lower electrode 58 having a fine pattern can also be formed (FIG. 15).

Subsequently, the iridium film 65 is processed into a predetermined shape by the ion milling method to form the lower electrode 58.
Then, the capacitor storage electrode 60 and the upper electrode 62 are formed on the lower electrode 58 to form the capacitor C (FIG. 13A). Then, a DRAM including one transistor and one capacitor is formed by the same method as in the second embodiment (FIG. 13B).

As described above, according to the present embodiment, the through hole 52 is buried by the selective growth of the iridium film,
Since the iridium film 65 to be the lower electrode 58 is grown in a non-selective manner, the plug 62 embedded in the through hole 52 and the lower electrode 58 can be continuously grown simply by changing the film forming conditions. Although the plug 64 and the lower electrode 58 are both formed of an iridium film in the above embodiment, one of them may be formed of an iridium oxide film, or both of them may be formed of an iridium oxide film. Even when the iridium oxide film is used, selective growth and non-selective growth can be easily controlled as shown in the first embodiment.

Further, the lower electrode 58 may be formed of a laminated film. For example, as shown in FIG. 16, the plug 64 may be formed by selective growth of an iridium film, and the lower electrode 58 may be formed by a laminated film of an iridium oxide film 72 and an iridium film 74 that are grown non-selectively. As shown in FIG. 17, the plug 64 may be formed by selective growth of an iridium oxide film, and the lower electrode 58 may be formed by a laminated film of an iridium film 70 and an iridium oxide film 72 that are non-selectively grown.

In the above embodiment, the method of continuously forming the plug 64 and the lower electrode 58 in the DRAM is shown as an example of the method of manufacturing the semiconductor device in which the selective growth and the non-selective growth are combined. It is not limited to the above applications.

[0062]

As described above, according to the present invention, the first substance is exposed in the first region, and the second substance is exposed in the second region. , Ir (DPM) ₃
Since the iridium film or the iridium oxide film is selectively deposited by the chemical vapor deposition method using as a raw material, there is no need to pattern the iridium film or the iridium oxide film by the ion milling method, and an iridium film having a fine pattern or An iridium oxide film can be formed.

In the above thin film forming method, the first
If Ti or TiN is used as the substance and silicon oxide is used as the second substance, the iridium film or the iridium oxide film can be deposited only on Ti or TiN. When depositing an iridium film in the above thin film forming method, the substrate on which the iridium film is deposited is
The temperature is set higher than 0 ° C. and lower than 550 ° C., and the film formation chamber for forming the iridium film is set higher than 0.1 Torr.
If the pressure is set lower than 20 Torr, the iridium film can be selectively grown.

When depositing the iridium oxide film in the above thin film forming method, the substrate on which the iridium oxide film is deposited is set to a temperature higher than 400 ° C. and lower than 600 ° C. to form the iridium oxide film. The film forming chamber is set to 0.
When the pressure is set higher than 1 Torr and lower than 30 Torr, the iridium oxide film can be selectively grown.

If the semiconductor device is formed by using the iridium film or the iridium oxide film formed by the above-mentioned thin film forming method, the semiconductor device having the iridium film or the iridium oxide film can be miniaturized. Further, in a semiconductor device having a capacitor in which a lower electrode, a dielectric film, and an upper electrode are sequentially stacked, an iridium film or iridium oxide film formed by the above thin film forming method is used as the upper electrode or the lower electrode. Since the film is used, the step of patterning the iridium film or the iridium oxide film is unnecessary, and the capacitor having a fine pattern can be formed.

Further, a plug selectively formed in the through hole formed in the base substrate by the above-described thin film forming method and an iridium film or a non-selectively formed on the base substrate in which the plug is formed, Since the semiconductor device is composed of the electrode made of the iridium oxide film, the steps of filling the through hole and forming the electrode can be simplified.

Further, a barrier layer forming step of forming a barrier layer made of a Ti film or a TiN film in the first region on the base substrate and the thin film forming method described above are used to selectively form an iridium film or a film on the barrier layer. A lower electrode forming step of depositing an iridium oxide film to form a lower electrode, a dielectric film forming step of forming a dielectric film on the lower electrode, and an upper electrode forming step of forming an upper electrode on the dielectric film. Since the semiconductor device is manufactured by the method described above, patterning of the lower electrode is unnecessary, and the manufacturing process can be simplified. In addition, fine patterns can be formed.

In addition, a first thin film forming step of selectively forming a first iridium film or a first iridium oxide film in a predetermined region of the deposition substrate, and a first selectively formed film.
And a second thin film forming step of depositing the second iridium film or the second iridium oxide film on the entire surface of the deposition target substrate having the iridium film or the first iridium oxide film. it can.

Further, a plug forming step of selectively burying an iridium film or an iridium oxide film in the through hole of the deposition target substrate having a silicon oxide film having a through hole formed on the surface thereof by the above-mentioned thin film forming method, If a semiconductor device is manufactured by an electrode forming step of non-selectively forming an iridium film or an iridium oxide film on a silicon oxide film in which a plug is embedded in a through hole and forming an electrode connected to the plug, The filling of the through hole and the formation of the electrode can be continuously performed by simply changing the deposition conditions of the iridium film or the iridium oxide film. Thereby, the manufacturing process of the semiconductor device can be simplified.

[Brief description of drawings]

FIG. 1 is a schematic view of a CVD apparatus used in a thin film forming method according to a first embodiment of the present invention.

FIG. 2 is a graph showing dependency of deposition rate on film forming conditions when an iridium film is formed on a silicon oxide film.

FIG. 3 is a graph showing the film forming condition dependency of the deposition rate when an iridium film is formed on a TiN film.

FIG. 4 is a graph showing dependency of deposition rate on film forming conditions when an iridium oxide film is formed on a silicon oxide film.

FIG. 5 is a schematic sectional view showing the structure of a semiconductor device according to a second embodiment of the present invention.

FIG. 6 is a process sectional view (1) illustrating the method for manufacturing the semiconductor device according to the second embodiment of the present invention.

FIG. 7 is a process cross-sectional view (2) illustrating the method for manufacturing the semiconductor device according to the second embodiment of the present invention.

FIG. 8 is a schematic cross-sectional view (part 1) showing the structure of a semiconductor device according to a modification of the second embodiment of the invention.

FIG. 9 is a schematic cross-sectional view (No. 2) showing the structure of the semiconductor device according to the modification of the second embodiment of the present invention.

FIG. 10 is a schematic cross-sectional view (part 3) showing the structure of the semiconductor device according to the modification of the second embodiment of the present invention.

FIG. 11 is a schematic sectional view showing the structure of a semiconductor device according to a third embodiment of the present invention.

FIG. 12 is a process sectional view (1) illustrating the method for manufacturing the semiconductor device according to the third embodiment of the present invention.

FIG. 13 is a process sectional view (2) illustrating the method for manufacturing the semiconductor device according to the third embodiment of the present invention.

FIG. 14 is a schematic cross-sectional view (No. 1) showing the structure of the semiconductor device according to the modification of the third embodiment of the invention.

FIG. 15 is a schematic cross-sectional view (No. 2) showing the structure of the semiconductor device according to the modification of the third embodiment of the invention.

FIG. 16 is a schematic cross-sectional view (3) showing the structure of the semiconductor device according to the modification of the third embodiment of the present invention.

FIG. 17 is a schematic cross-sectional view (No. 4) showing the structure of the semiconductor device according to the modification of the third embodiment of the present invention.

[Explanation of symbols]

 10 ... Deposition chamber 12 ... Vacuum pump 14 ... Substrate 16 ... Susceptor 17 ... Lamp heater 18 ... Gas supply pipe 20 ... Gas supply pipe 22 ... Shower head 24 ... Gas control device 26 ... Raw material container 28 ... Constant temperature bath 30 ... Gas supply Piping 32 ... Heater 40 ... Silicon substrate 42 ... Element isolation film 44 ... Source diffusion layer 46 ... Drain diffusion layer 48 ... Gate electrode 49 ... Insulating film 50 ... Wiring layer 52 ... Through hole 54 ... Interlayer insulating film 56 ... Barrier layer 58 ... Lower electrode 60 ... Capacitor storage electrode 62 ... Upper electrode 64 ... Plug 65 ... Iridium film 66 ... Interlayer insulating film 67 ... TiN film 68 ... Wiring layer 70 ... Iridium film 72 ... Iridium oxide film 74 ... Iridium film

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁶ Identification code Internal reference number FI Technical indication H01L 21/822 H01L 27/10 651 27/108 21/8242

Claims (10)

[Claims] 1. A thin film forming method for forming an iridium film or an iridium oxide film by a chemical vapor deposition method using Ir (DPM) ₃ as a raw material, wherein the first substance is exposed in a first region, A method for forming a thin film, which comprises selectively depositing an iridium film or an iridium oxide film on the first region on the deposition target substrate where the second substance is exposed in the second region. 2. The thin film forming method according to claim 1, wherein the first substance is Ti or TiN, and the second substance is silicon oxide. 3. The thin film forming method according to claim 1, wherein when depositing the iridium film, the substrate on which the iridium film is deposited is set to a temperature higher than 400 ° C. and lower than 550 ° C. A method for forming a thin film, characterized in that the film forming chamber for forming the iridium film is set to a pressure higher than 0.1 Torr and lower than 20 Torr. 4. The thin film forming method according to claim 1, wherein when depositing the iridium oxide film, the substrate on which the iridium oxide film is deposited is higher than 400.degree.
The temperature is set lower than 0 ° C., and the film formation chamber for forming the iridium oxide film is set to a temperature higher than 0.1 Torr and a pressure of 30 Torr
A method for forming a thin film, which comprises setting a lower pressure. 5. A semiconductor device comprising an iridium film or an iridium oxide film formed by the thin film forming method according to claim 1. 6. A semiconductor device having a capacitor formed by sequentially stacking a lower electrode, a dielectric film, and an upper electrode, wherein the upper electrode or the lower electrode is according to any one of claims 1 to 4. A semiconductor device comprising an iridium film or an iridium oxide film formed by the thin film forming method described above. 7. A plug selectively formed in a through hole formed in a base substrate by the thin film forming method according to claim 1, and a base substrate on which the plug is formed. A semiconductor device comprising: an electrode made of an iridium film or an iridium oxide film that is non-selectively formed. 8. A barrier layer forming step of forming a barrier layer made of a Ti film or a TiN film in a first region on a base substrate, and the thin film forming method according to claim 1. A lower electrode forming step of selectively depositing an iridium film or an iridium oxide film on the barrier layer to form a lower electrode; a dielectric film forming step of forming a dielectric film on the lower electrode; and the dielectric film. An upper electrode forming step of forming an upper electrode thereon. 9. A first thin film forming step of selectively forming a first iridium film or a first iridium oxide film in a predetermined region of a substrate to be deposited, and the first film selectively formed. A second thin film forming step of depositing a second iridium film or a second iridium oxide film on the entire surface of the deposition target substrate having the iridium film or the first iridium oxide film. Manufacturing method of semiconductor device. 10. The iridium film or the iridium film is selectively formed in the through hole of the deposition substrate having a silicon oxide film having a through hole formed on the surface thereof by the thin film forming method according to claim 1. A step of forming a plug for burying an iridium oxide film, and forming an iridium film or an iridium oxide film non-selectively on the silicon oxide film in which the plug is buried in the through hole, and forming an electrode connected to the plug. A method of manufacturing a semiconductor device, comprising the step of forming an electrode.