JP2000058529A - Chemical vapor deposition device and manufacture of semiconductor device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a thermal chemical vapor deposition device wherein film- forming which is conformal to a cylindrical capacitor structure or a trench of high-aspect ratio is allowed while excellent in crystallinity. SOLUTION: In a vapor deposition device wherein, with a reactive furnace 2 provided, a gas head 6 which blows a reactive gas and an oxidant gas into the furnace separately and a susceptor 10 wherein a substrate facing the gas head 6 is placed on the upper surface are provided in the reactive furnace 2 while the gas head 6 used in combination with a gas manifold 8, a column filling carburetor 30 for vaporizing a liquid reactive material is provided. The column filling carburetor 30 is connected to the gas manifold 8 by pipes 31 and 32 comprising, in the middle, a 3-way valve 34 with an exhaust pipe connected at an end, with a piping distance from the column filling carburetor 30 to the gas manifold 8 1 m or shorter.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a liquid metal material alone, or a metal liquid material and an oxidant such as oxygen or nitrous oxide in combination high dielectric insulating film Ta ₂ O ₅ and the metal film RuO
_{The present} invention relates to a vapor phase growth apparatus capable of forming ₂ or Ru. More specifically, the present invention relates to a method for manufacturing a semiconductor capacitor device structure using the above film.

[0002]

2. Description of the Related Art In recent years, the method of forming a high dielectric insulating film and a metal film of a capacitor has been shifted from a sputtering method to a CVD method (chemical vapor deposition method). Sputtering uniformly forms a film of a target material on a wafer by the embedding action of injecting Ar gas particles into a metal target in a vacuum. Further, an oxidizing agent is added to the above-described sputtering method, and it is possible to form not only a metal film but also an insulating film by a so-called reactive sputtering method.

However, the film formation by the sputtering method cannot obtain a uniform film thickness in a complicated capacitor structure with miniaturization of a semiconductor, and the step coverage is beginning to be seen. Therefore, thermal CVD showing excellent step coverage characteristics instead of sputtering
The law is drawing attention. The step coverage of the film formed by the thermal CVD method is different from that of the sputtering method, and a uniform film thickness can be deposited even in a complicated capacitor structure by optimizing a supply gas condition in a portion heated uniformly. It is possible.

[0004] JP-A-9-153485 and JP-A-9-153485
No. 9-30893 discloses a single-wafer type cold wall.
A thermal CVD apparatus having a reaction furnace of the type is described,
Ta _Two0_FiveInsulation of high-dielectric films using liquid materials including films
A thermal CVD method for forming an edge film is disclosed.

An increase in the capacity of a DRAM in a semiconductor IC means miniaturization of a memory cell. For miniaturization of a memory cell, it is important how much storage capacity can be secured for a reduced capacitor area.

Conventional DRAMs (up to 1M) have a relatively large cell area with a planar capacitor structure, and therefore, in order to secure a storage capacity, it has been supplemented by making the gate capacitor insulating film thin. However, as miniaturization (4M or more) progresses, it becomes difficult to secure a storage capacity in a planar structure, and a three-dimensional capacity structure is indispensable.

As a 16M DRAM capacitor structure, a simple STC (stack trench capacity), a fin or a trench structure has been generally used. Polysilicon is used for the electrode material, and Si ₃ is used for the capacitor insulating film.
N ₄ is the mainstream. Si ₃ N ₄ is 650 to 650 by low pressure CVD.
Films are often formed at a high temperature of 750 ° C., and are characterized by a relatively high dielectric constant of 7 to 8 and excellent uniformity of film thickness and film quality and excellent step coverage. Is also used.

However, due to the high integration, the securing of storage capacity required for countermeasures against soft errors due to α rays has reached its limit. The amount of charge stored in the cell is proportional to the capacitance (C) and C = ε
It is determined by ε ₀ xS / d (where ε ₀ : dielectric constant in vacuum, S: capacitor area, d: film thickness).

Therefore, the first measure is to increase the surface area of the capacitor in a three-dimensional structure, that is, in the case of a fin structure, a method of stacking two or three fins or in a trench structure, the aspect ratio is increased to obtain a surface area. There are methods, but these measures are very complicated in terms of processes and have limitations in structure and manufacturing technology.

[0010] The second method is to reduce the film thickness. However, as a result of reducing the film thickness, there is a concern that a problem such as an increase in leakage current may occur, and the second method has a limit. Therefore, the most effective means is to form an insulating film using a material having a high dielectric constant (ε). Currently, Ta ₂ 0 ₅ film using a thermal CVD is used for the capacitor insulating film.

[0011] Ta ₂ 0 ₅ film characteristics of the dielectric breakdown voltage ~5MW /
cm, the dielectric constant (ε) is 〜28, which is about four times the value of Si ₃ N ₄ . Mls (Metal / Insu
A problem with the Ta ₂ O ₅ film in the (later / Poly-Si) capacitor structure is the generation of a leak current due to oxygen deficiency, and the leak current causes a decrease in capacitance. This is because impurities such as C (carbon) in the liquid material reflect on the electrical characteristics of the formed film. Therefore, post-treatment at a high temperature for replenishing oxygen, such as oxygen plasma or ozone annealing, is required after film formation.

Further, when polysilicon is used as a base electrode of the Ta ₂ O ₅ film, SiO ₂ is generated on the polysilicon by this oxidation annealing treatment, which is one of the causes of the leak current generation of the Ta ₂ O ₅ film. It has become one.

Therefore, studies are currently being made on a base metal electrode film suitable for a Ta ₂ O ₅ film. It adhesion between the Ta ₂ O ₅ film as a condition of the base electrode film is good, Ta ₂
The reaction layer (oxide film) is not formed between the O ₅ film and the electrode, and the step coverage is excellent.

Ru or RuO ₂ is considered to be a promising underlying electrode film for the Ta ₂ O ₅ film, and is currently formed by sputtering.

Since the RuO ₂ film exhibits conductivity, a Ta ₂ O ₅ film is formed on the Ru film, and a RuO ₂ film is formed on the interface between the Ru film and the Ta ₂ O ₅ film by high-temperature O ₃ annealing (RTO). Even if the reaction layer is formed, there is no problem that the capacity of the Ta ₂ O ₅ film decreases. Further, the RuO ₂ film itself can be used as a base electrode film of the Ta ₂ O ₅ film.

On the other hand, as a problem of the Ru electrode film formed by sputtering, a uniform and high-aspect coverage cannot be obtained for a complicated and high-aspect structure of a capacitor accompanying miniaturization of a memory cell. Unable to build structure.

[0017]

SUMMARY OF THE INVENTION Accordingly, an object of the present invention is to provide a thermal chemical vapor deposition apparatus capable of forming a film with high conformality and excellent crystallinity on a high aspect trench or cylindrical capacitor structure. It is to be.

Another object of the present invention is to provide a thermal chemical vapor deposition for forming Ru or RuO ₂ by using a metallic liquid material Ru (C ₅ H ₄ C ₂ H ₅ ) for upper and lower electrodes of a Ta ₂ O ₅ film. It is to provide a device.

Another object of the present invention is to provide a method for manufacturing a semiconductor device having a stable capacitor structure at a low cost with a reduced processing time by forming a conventional Ta ₂ O ₅ film and a Ru or RuO ₂ film of the present invention. It is to provide.

[0020]

An object of the present invention is to provide a gas head having a reaction furnace in which a reaction gas and an oxidizing gas can be separately blown into the furnace. The gas head has a susceptor on which a substrate is placed facing the upper surface, and the gas head has a column filling vaporizer for vaporizing a liquid reaction material in a vapor phase growth apparatus used in combination with a gas manifold. The column-filled vaporizer and the gas manifold are solved by being connected by a pipe having a three-way valve having an exhaust pipe connected to one end thereof.

It is preferable that the distance between the column-filled vaporizer and the gas manifold is 1 m or less.

[0022]

According to the device structure of the embodiment of the present invention, the vaporized _{Ru (C 5 H 4 C 2} H 5) with oxygen or nitrous gas head oxidizing nitrogen can be supplied to the reactor separately each oxidant By having the above, no reaction occurs in the pipe and the gas head, and clogging of the pipe by a reactant is eliminated. As a result, generation of foreign matter is suppressed.

Further, the distance from the column-filled vaporizer to the gas manifold is reduced to 1 m or less, and a three-way valve having a vent line is provided between the two. It is effective in preventing re-liquefaction in the piping. In addition, until the set gas flow rate becomes stable, the vaporized gas discharged from the exhaust pipe (vent line) connected to one end of the three-way valve can be reduced, and furthermore, the three-way valve having the vent line is more stable by installing the three-way valve. Supply of vaporized gas becomes possible.

In the apparatus of the present invention, by adopting such a configuration, it is possible to form a metal electrode film having excellent coverage with the conventional high dielectric film Ta ₂ O _5, and to cope with the giga without leakage current. Can be constructed.

FIG. 1 is a schematic sectional view of a reaction chamber of a vapor phase growth apparatus according to the present invention. The reactor 2 of this apparatus is substantially the same as a single-wafer cold wall type reactor described in JP-A-9-153485 and JP-A-9-30893.

A gas head 6 is provided above the reaction furnace 2. The gas head 6 is mounted on the lower surface side of the gas head base 1, while the gas manifold 8 is mounted on the upper surface of the gas head base 1. Gas manifold 8
Vaporized gas _{(e.g., Ru (C 5 H 4 C} 2 H 5)) to insert the gas conduit 5a and an oxidizing agent (e.g., oxygen or nitrous oxide) gas conduit 4a to introduce is provided in the . The gas conduits 5a and 4a communicate with the gas conduits 4b and 5b of the gas head base 1, respectively, and further communicate with the gas conduits 5c and 4c provided in the gas head 6. At the lower ends of the gas conduits 5c and 4c provided in the gas head 6, there are provided minute gas outlets 9 opening toward the inside of the reaction furnace. Further, in the gas manifold 8 and the gas head base 1, in order to prevent re-liquefaction of the vaporized gas,
A conduit 7 for circulating the heating heat medium is provided. Instead of providing the heating medium circulation path, another heating means (for example, a coil heater or the like) can be used.

A quartz hood 15 is provided on the chamber base 3. The quartz hood 15 is provided detachably by fastening means 23. A heater 13 is provided inside the quartz hood 15. A quartz insulating material 18 is provided below the heater 13, and a three-tiered reflector 35 is provided below the insulating material 18. Although it is not necessary to use the reflector 35, the use thereof increases the thermal efficiency. When used, the reflector 35 may have at least one stage. The material of the reflector is not particularly limited. For example, molybdenum or the like is suitably used as a material for the reflector 35. The heater 13 is, for example, Si
All known materials such as C, nichrome wire and carpon can be used. The heater 13 is divided into a plurality of pieces along the circumferential direction, and can drive only a necessary cylinder portion (for example, only the outermost peripheral portion) as desired.

The thickness of the quartz hood 15 is not particularly limited.
No. Pressure fluctuation in the reactor and on the top of quartz hood 15
Strength to withstand the weight of the susceptor 10 to be placed
It is sufficient if the thickness has a necessary and sufficient value. For example, the present invention
When using the vapor deposition apparatus of the above as a decompression CVD apparatus,
The pressure in the reactor 2 is reduced to about 1 Torr
The upper thickness of the quartz hood 15 is about 25 mm.
The thickness of the leg is about 10mm, and the thickness of the foot is
It is about 20 mm. Other thicknesses can of course be used
You. The pressure in the furnace and the pressure in the quartz hood 15 are matched.
The thickness of the quartz hood 15 can be reduced by adjusting
It is possible. However, the pressure in the hood is lower than the pressure in the furnace.
It is better to prevent heat diffusion to the quartz hood 15
Efficiency is improved. Therefore, the exhaust in the quartz hood 15
10 by dry pump 24^-3-10 ^-FourKept in Torr
Have been. The inside of the reactor 2 is a molecular drag pump.
It is exhausted by 25.

The susceptor 10 is placed on the upper surface of the quartz hood 15 substantially at the center. The susceptor 10 includes an inner susceptor 10 on which a wafer is actually mounted, and an outer susceptor 11 surrounding the susceptor. The outer susceptor 11 is also called a guide ring or a wafer guide.

The material for forming the inner susceptor 10 and the outer susceptor 11 is not particularly limited, but is preferably made of, for example, glassy carbon or the like in order to prevent the wafer from being contaminated with heavy metals. A lifting claw 12 for raising and lowering the wafer on the inner susceptor 10 for transferring the wafer is provided beside the quartz hood 15.

A suitable cylindrical portion of the chamber base 3 covered with the quartz hood 15 is notched, and a heater base 21 made of, for example, aluminum or stainless steel is provided at that portion. A window 19 made of quartz is provided substantially at the center of the heater base 21. A radiation thermometer 22 is provided to face the window 19. Further, openings 14 and 20 are provided at respective positions of the heater 13 and the reflector 35 corresponding to the quartz window 19 of the heater base 21. Since the quartz hood 15 and the insulating material 18 are each made of quartz and transparent, the temperature of the susceptor 10 can be measured by a radiation thermometer 22 provided outside the reactor.

The external susceptor on the quartz hood 15 is constructed by stacking two parts in a horizontal direction, that is, vertically. In the present susceptor structure, the inner susceptor and the outer susceptor are not in contact with each other, and there is a gap in the range of 0.5 to 1.5 mm at the boundary between the two members. The division of the external susceptor 11 is not limited to two. It may be divided into three or four. What is important here is that no means is taken to make the divided pieces adhere to each other. Therefore,
The divided pieces are simply stacked, and the surface of the customer divided piece may have an uneven gap in the mirror surface. Further, the thickness of each divided piece may be the same as each other, or may be different. Although not shown, each divided piece is positioned by a positioning pin.

The reaction gas (for example, (Ta (OC
₂ H ₅ ) ₄ ) or Ru (C ₅ H ₄ C ₂ H ₅ ), etc.) and an oxidant (eg, oxygen or nitrous oxide) are each separately supplied from separate gas conduits into the reaction chamber. . Also,
Although not shown, the reaction gas and the oxidizing agent can be supplied at the same time by supplying the reaction gas from the state in which the oxidizing agent is first flown into the reaction furnace and the inside of the reaction furnace is replaced with the oxidizing agent. A possible valve control mechanism is provided, and conversely, the oxidizing agent can be introduced after the reaction gas is supplied first.

The reaction gas is supplied from a liquid reaction material tank 28 by N ₂ gas under pressure and sent to a column filling vaporizer 30 via a liquid mass flow controller 26, where it is vaporized. Liquid mass flow controller 2
No. 6 is capable of controlling the flow rate within the range of 0.02 to 2 sccm. Although not shown, an appropriate constant temperature mechanism is provided from the liquid material tank 28 to the column filling vaporizer 30. Reference numeral 27 indicates an air valve.

The carrier gas (for example, N ₂ ) introduced into the column packed vaporizer 30 is supplied to the gas mass flow controller 2.
9 at a flow rate in the range of 500-5000 sccm.

The column packed vaporizer 30 is 100 to 25
The temperature can be raised to 0 ° C., the supplied liquid reaction material is vaporized, and the reaction gas is supplied to the gas head 6 by the carrier gas (N ₂ ).

FIG. 8 is an enlarged schematic view of the column packed vaporizer 30. The vaporizer 30 is provided with a metallic liquid reaction material Ru (C ₅ H ₄ C ₄₎ controlled by the liquid mass flow controller 26.
H ₅ ) and carrier gas N ₂ controlled by the gas mass flow controller 29 are supplied from different inlets into the column heated to 200 ° C. or higher by the block heater 36 and vaporized.

In the column, a Ti having an average particle size of 0.8 mm was used.
The ball 37 is filled. Conventionally, the filler used for TEOS has been made of SUS, but RuO ₂
When forming a film, prevention of film contamination is particularly important.
A product made of Ti which has a low risk of metal contamination is used.

Further, the 0.2 mm capillary 3 of the vaporizer is used.
8 is characterized in that the tip is located 5 to 7 cm in the column. This is intended to reduce the pressure in the column. The purpose of reducing the pressure in the column will be described with reference to the vapor pressure curve of TEOS shown in FIG.
When the tip of the capillary 38 is at the position B (see FIG. 8), the resistance to the outlet of the reaction gas is reduced and the pressure in the column is reduced when the tip is at the position B. Become. The decrease in the pressure in the column means that the vapor pressure in the vapor pressure curve of TEOS in FIG.
It means that it can be reduced from (a) to (b), and consequently,
The temperature can be reduced from (c) to (d), and the difference can be used as a margin. Therefore, even when using a metallic liquid reaction material _{Ru (C 5 H 4 C 4} H 5), it is possible to lower the same temperature.

In an actual operation, the temperature can be set at the allowable limit temperature of the vaporizer, and stability of gas supply and mechanical reliability of the vaporizer can be secured by the position of the capillary tip at the time of filling the column. . Further, by using this vaporizer, a vaporized gas free of metal contamination can be obtained stably. Generally, the smaller the pressure difference between the vent side and the gas head side, the more stable gas supply becomes possible. The column packed vaporizer 30 used in the present invention is commercially available from S-Tech Corporation.

A three-way valve 34 having a vent line (exhaust pipe) 33 is provided between the column filling vaporizer 30 and the gas head manifold 8. Any three-way valve 34 can be used as long as it is commonly used in piping applications such as fluid transportation. The switching operation of the three-way valve 34 switches the opening and closing of the pipes 32 and 33 by an electromagnetic valve method.

The pipes 31 and 32 from the column filling vaporizer 30 to the gas head manifold 8 are provided with heating means at 250 ° C. or lower to prevent reliquefaction of the vaporized reaction gas. The three-way valve 34 having the vent line 33 is installed in the column filling vaporizer 30 by discharging the gas into the vent line 33 until the reaction starts, that is, until the vaporized reaction gas is introduced into the reaction furnace 2. Thus, a stable flow rate can be obtained, and the set flow rate can be instantaneously supplied to the reaction chamber even when the three-way valve 34 is switched during film formation. Further, with this configuration, the amount of the reaction gas discharged until the film is formed can be reduced, which is effective in improving the throughput.

Accordingly, in order to obtain a faster and more stable flow rate, it is preferable to shorten the distance D from the column-filled vaporizer 30 to the gas head manifold 8. In the device of the present invention, the distance D is preferably 1 m or less.
More preferably, the distance D is 0.5 m or less. Although the lower limit of the distance D is not particularly limited, the three-way valve 3 used is
4 and the minimum limit in mechanical assembly in which the column-filled vaporizer 30, the three-way valve 34, and the gas head manifold 8 can be interconnected by pipes 31 and 33.

As shown in FIG. 1, the gas head 6
By connecting the high frequency power supply 42 via the matching box 40, it is possible to generate a plasma discharge in the reaction furnace. Therefore, automatic cleaning by plasma excitation can be performed. The power supply frequency is not particularly limited, but is generally preferably 13.56 MHz or higher. Although not shown, for example, a chlorine gas for cleaning (eg, Cl
F ₃ ) can be fed into the reactor 2. Alternatively, a cleaning chlorine-based gas may be supplied from the conduit 5a. An inert gas such as N ₂ or Ar can be mixed with the gaseous chlorine-based gas. 13.56 MH is applied to the gas head 6 using a chlorine-based gas containing ClF _3.
Applying a high frequency of z to reduce the pressure in the reaction furnace to 10 Torr or less and generating uniform and stable plasma in the reaction furnace 2, thereby removing the RuO ₂ film and the Ru film adhered at the time of film formation at a high speed. Can be. The material of the gas head 6 is made of aluminum, and the material of the susceptor is a conductor such as carbon or aluminum.

[0045] In the cleaning of conventional the Ta ₂ O ₅ film thermal chemical vapor deposition apparatus for forming, and the ClF ₃ gas vaporized fed to the reaction furnace, and thickly deposited like the reactor wall Ta ₂
Although the O ₅ film has been removed, the cleaning is not uniform, so that the in-plane and inter-plane uniformity after the cleaning may be deteriorated. In the apparatus of the present invention, the film on the gas head and the susceptor is uniformly removed by the cleaning using the plasma. As a result, the cleaning time is shortened, so that not only an improvement in the throughput is obtained, but also an excellent effect that the process cost can be reduced by reducing the amount of the cleaning gas is obtained.

In the conventional cleaning method of a thermal chemical vapor deposition apparatus for forming a Ta ₂ O ₅ film, Cl
F ₃ gas was introduced from two places toward the susceptor. In the apparatus of the present invention, a cleaning method by plasma excitation is performed. An experiment was conducted on the difference in cleaning effect between the conventional apparatus and the apparatus of the present invention. In the experiment, a Ta ₂ O ₅ film was deposited on a Si substrate for about 2000 angstroms (hereinafter referred to as “A”), cleaned for 10 minutes, and the film thickness was measured visually and by an ellipsometer.
The removal distribution was examined. As a result, it was confirmed that in the conventional cleaning method, cleaning in the gas introduction direction was remarkable, but cleaning in other directions was insufficient. On the other hand, in the cleaning method of the present invention, the film on the reactor wall and the Si substrate could be uniformly removed. The cleaning speed using plasma was about five times the speed of the conventional cleaning method.

Next, foreign substances were confirmed in the continuous film formation after cleaning. Measurement is 1000A after cleaning
The film formation was carried out to the extent that the film was empty, and then the number of foreign substances was measured when 10 sheets were continuously formed at 100A. As a result, the number of foreign particles was 128 in the conventional method, but only 18 in the plasma excitation method of the present invention. This difference is considered to be due to the remaining film that could not be removed by cleaning in the conventional method.

FIG. 2 is a schematic plan view of an example of the vapor phase growth apparatus of the present invention. For example, the present apparatus can be configured with up to three chambers. The first reactor 105 deposits a Ta ₂ O ₅ film, and the second reactor 107 deposits a Ru or RuO ₂ film. The third reaction furnace 108 can be configured as a post-processing chamber for performing an oxidation treatment. It is also possible to form the same film type in three reactors. A molecular drag pump 106 is provided adjacent to the reactor, and each reactor can perform film formation and post-treatment at 1 Torr or less even when the total flow rate of the reaction gas is set to 1000 sccm / min or more. It is. A wafer (not shown) is placed on a buffer 104 in a buffer chamber 103 by an atmosphere-side transfer arm 110 from a 25-sheet storage cassette 102 of a wafer cassette unit 101 and is held in a vacuum. The vacuum transfer chamber 111 and the film formation reaction chambers 105 and 107 which are held in a vacuum in advance are transferred from the buffer chamber 103 to the respective reaction chambers by the vacuum transfer arm 109 to perform film formation and post-processing. In the present apparatus, a film having a size of 3, 4, 5, 6, 8, or 12 inches can be formed. In addition, a wafer having a larger size can naturally be processed.

By using Ta (OC ₂ H ₅ ) ₄ as the liquid reaction material and using oxygen as the oxidizing agent, a Ta ₂ O ₅ film can be formed in the first reaction furnace. On the other hand, by using Ru (C ₅ H ₄ C ₂ H ₅ ) as a liquid reaction material and using oxygen or nitrous oxide as an oxidizing agent, R
A uO ₂ film can be formed. Alternatively, a Ru film can be formed by thermally decomposing only Ru (C ₅ H ₄ C ₂ H ₅ ) as a liquid reaction material in a second reactor. The converse is also possible. Although the film formation temperature is not particularly limited,
Generally, it is preferable to be in the range of 400 to 700 ° C.

[0050]

EXAMPLES Next, RuO ₂ by vapor phase growth apparatus of the present invention
An example of forming a film and a Ta ₂ O ₅ film will be described. RuO ₂
The film was formed under the conditions of a substrate temperature of 500 ° C. and a liquid source Ru.
(C ₅ H ₄ C ₂ H ₅ ) flow rate 0.05 sccm, oxidizing agent O ₂ flow rate 1500 sccm, forming pressure 0.5 Torr, carrier gas N ₂ flow rate 1000 sccm, column filling vaporizer temperature 250 ° C., gas head from column filling vaporizer The distance to the manifold was 50 cm, the electrode interval was 100 mm, and the size of the wafer to be processed was 8 inches. The Ta ₂ O ₅ film was formed under the conditions of a substrate temperature of 550 ° C., a liquid source Ta (OC ₂
H ₅ ) ₄ flow rate 0.06 sccm, oxidant O ₂ flow rate 1000
The sccm was 200 ° C. in the temperature of the column-filled vaporizer, and the other conditions were the same as the conditions for forming the RuO ₂ film.

FIG. 3 shows the in-plane uniformity results on an 8-inch wafer. As shown in FIG.
5% or less is secured. FIG. 4 shows the result of examining the inter-plane uniformity when 300 sheets of continuous film were formed. In this evaluation, the film could be formed at ± 4% or less. This is because the distance from the column packed vaporizer to the reaction furnace is short, and a three-way valve with a vent line is installed, so that the vaporized reaction gas can be supplied to the reaction chamber instantaneously at the same time as the valve is switched at a stable flow rate. It is.

FIG. 5 shows the evaluation result of the coverage of the RuO ₂ film. FIG. 5A shows the coverage when the film is formed by the conventional sputtering, and FIG. 5B shows the result when the film is formed by the apparatus of the present invention. The material of the coverage evaluation sample 201 is silicon and the aspect ratio is 5 or more. This structure is one of the typical structures of a capacitor called a cylindrical type (crown). In the sputtering method of FIG. 5A, since the aspect ratio is high at the bottom and the back of the cylinder, the film is not uniformly formed. It is difficult to construct a stable capacitor structure. On the other hand, in the film formation by the apparatus of the present invention, since the film is deposited by a thermal reaction, it is possible to form a uniform and stable RuO ₂ film even for a high aspect and complicated sample.

FIG. 6 shows an example of a conventional capacitor structure.
In the capacitor structure shown in FIG. 6, a polysilicon 204 is used as a lower electrode, a Ta ₂ O ₅ film is used as a high dielectric film 205, and a TiN or TaN film is used as an upper electrode 206.
During this problem point of the capacitor structure, when forming Ta ₂ O ₅ film high dielectric layer 205 on the polysilicon 204 of the lower electrode, an oxide film is formed on the polysilicon 204, Ta ₂
That is, the capacity of the O ₅ film is reduced. Therefore, at present, high-temperature nitriding surface treatment (RTN) is performed so that an oxide film is not formed on the polysilicon 204 of the lower electrode, and then a Ta ₂ O ₅ film 205 is formed. Therefore, Ta ₂
By forming an electrode on which no oxide film is formed at the interface as an ideal upper and lower electrode film of the O ₅ film, a stable capacitor can be obtained. Reference numeral 200 indicates a silicon substrate.

FIGS. 7A and 7B show Ru according to the present invention.
An example of a stable capacitor structure using an O ₂ film will be described. In the capacitor structure shown in FIG.
7, any one of Ru or RuO ₂ or Ru.RuO ₂ is used, a Ta ₂ O ₅ film is used as the high dielectric film 205, and Ru, RuO ₂ or Ru is used for the upper electrode 208.
• Use one of the RuO _2. Therefore, FIG.
In the capacitor structure shown in FIG. 1, for example, Ru / Ta ₂
O ₅ / RuO ₂ , Ru / Ta ₂ O ₅ / Ru, Ru / Ta ₂ O ₅
/ RuO ₂ · Ru, RuO ₂ / Ta ₂ O ₅ / Ru, or Ru
It has any structure of O ₂ / Ta ₂ O ₅ / RuO ₂ .Ru. Further, in the capacitor structure shown in FIG.
Ru or RuO ₂ or Ru · Ru is applied to the lower electrode 207.
An O ₂ film is used, a Ta ₂ O ₅ film is used as the high dielectric film 205, and a Ru or RuO ₂ or Ru · RuO ₂ film is used for the upper electrode 208. In the capacitor structure shown in FIG. 7B, Ti, TiN or TaN is formed at the interface between the silicon substrate 200 and the lower electrode 207.
Is formed. This adhesive layer 20
Due to 9, the adhesion between the silicon substrate and the capacitor structure is enhanced.

[0055]

As described above, according to the present invention,
Uniform and stable RuO ₂ deposition with a high aspect ratio and a complicated capacitor structure is possible. Further, it is possible to construct a capacitor structure to be mounted on a 1G or later DRAM, system LSI, or the like with one device.

[Brief description of the drawings]

FIG. 1 is a schematic sectional view of a reaction chamber of a vapor phase growth apparatus according to the present invention.

FIG. 2 is a schematic plan view of an example of a vapor phase growth apparatus of the present invention.

FIG. 3 shows a RuO film formed by the apparatus of the present invention shown in FIG.
FIG. 3 is a characteristic diagram showing uniformity of _two film thicknesses within a wafer surface.

FIG. 4 shows a RuO ₂ film of 3 in the apparatus of the present invention shown in FIG.
FIG. 9 is a characteristic diagram illustrating a relationship between the number of processed wafers and a film thickness variation rate when a continuous film formation process is performed on 00 wafers.

5A and 5B are cross-sectional views illustrating evaluation results of coverage of a RuO ₂ film, and FIG. 5A is a cross-sectional view illustrating evaluation results of coverage when a film is formed by a conventional sputtering method, and FIG.
FIG. 2 is a cross-sectional view showing evaluation results of coverage when a film is formed by the apparatus of the present invention shown in FIG.

FIG. 6 is a schematic sectional view showing a conventional capacitor structure.

FIGS. 7A and 7B are schematic sectional views showing a capacitor structure using a RuO ₂ film according to the present invention, wherein FIG. 7A is an example in which no adhesive layer is used, and FIG. 7B is an example in which an adhesive layer is used. is there.

FIG. 8 is an enlarged schematic view of a column packed vaporizer.

FIG. 9 is a vapor pressure curve of TEOS.

[Explanation of symbols]

1 Gas head base 2 reactor 3 chamber base 4 O ₂ gas conduit 5 Ru gas conduit 6 gas head 7 for heating the heat medium canalization 8 gas manifold 9 gas outlet 10 susceptor 11 outside the susceptor 12 lifting claw 13 heater 14 opening Part 15 Quartz hood 16 Gate valve 17 Load lock chamber 18 Insulating material 19 Quartz glass window 20 Opening 21 Heater base 22 Radiation thermometer 23 Fastening means 24 Dry pump 25 Molecular drag pump 26 Liquid mass flow controller 27 Air valve 28 Liquid material tank 29 Mass flow controller for carrier gas N ₂ 30 Column filling vaporizer 31, 32 Vaporized Ru gas introduction pipe 33 Vent line 34 Three-way valve 35 Reflector 36 Block heater 37 Ti ball 38 Capillary 40 Matching Box 42 High-frequency power supply 101 Wafer cassette unit 102 Wafer cassette 103 Buffer chamber 104 Buffer 105 Ta ₂ O ₅ film forming reaction furnace 106 Molecular drag pump 107 RuO ₂ film forming reaction furnace 108 Post-processing reaction furnace 109 Vacuum transfer arm 110 Atmospheric transfer arm LL1 RuO ₂ film 204 lower electrode 205 high dielectric film 206 upper electrode 207 lower electrode 208 upper electrode 209 adhesive layer by RuO ₂ film 203 CVD method using the vacuum transfer chamber 200 silicon substrate 201 Si step coverage evaluation sample 202 sputtering

 ──────────────────────────────────────────────────続 き Continuation of the front page (72) Inventor Masayuki Hachiya 3-16-3 Higashi, Shibuya-ku, Tokyo Inside Hitachi Electronics Engineering Co., Ltd. (72) Eiji Sato Inventor 3-16-3 Higashi, 3-3-1-3 Shibuya-ku, Tokyo Hitachi Electronic Engineering Co., Ltd. F-term (reference) 4K030 AA11 AA14 AA24 BA01 BA17 BA18 BA38 BA42 BB12 CA04 DA06 DA09 EA01 EA05 FA03 JA06 JA10 JA18 KA17 LA01 LA02 LA15 5F045 AA04 AB31 AC09 AC11 AC15 AD08 AD09 AD10 AD11 AE19 AF03 AF10 DC DQ10 DQ17 EB02 EB06 EB08 EC08 EC09 EE02 EE13 EF05 EH05 EH14 EK05 EK10 EK26 EM02 GB13 5F083 AD14 AD15 GA27 JA06 JA39 JA40 JA43 PR21

Claims (14)

[Claims] A gas head capable of separately blowing a reaction gas and an oxidizing gas into the furnace, and a substrate mounted on an upper surface facing the gas head. A gas head having a column filling vaporizer for vaporizing a liquid reactive material in the chemical vapor deposition apparatus used in combination with the gas manifold. The gas manifold is
A chemical vapor deposition apparatus characterized in that it is connected by a pipe having a three-way valve having an exhaust pipe connected to one end thereof at an intermediate position. 2. The apparatus according to claim 1, wherein a piping distance from the column packed vaporizer to the gas manifold is 1 m or less. 3. The apparatus according to claim 2, wherein a piping distance from the column packed vaporizer to the gas manifold is 0.5 m or less. 4. A high-dielectric-constant insulating film constituting a high-dielectric memory in a semiconductor integrated circuit (IC) and a metal electrode film formed on and under the high-dielectric insulating film by a chemical vapor deposition apparatus according to claim 1. A method for manufacturing a semiconductor device, wherein a film is formed by a vapor deposition method (CVD). 5. The method according to claim 4, wherein the high dielectric memory has a metal electrode film / high dielectric insulating film / metal electrode film (MIM) structure on a silicon substrate. 6. The high dielectric insulating film is made of Ta ₂ O ₅ , and the Ta ₂ O ₅ high dielectric insulating film is made of
The method according to claim 4, wherein the film is formed using (OC ₂ H ₅ ) ₄ and using oxygen as an oxidizing agent. 7. The method according to claim 6, further comprising a step of thermally oxidizing the high dielectric insulating film to improve the film quality. 8. The metal electrode film is made of RuO ₂ and / or R
u, and the RuO ₂ and / or Ru metal electrode film is
Ru (C ₅ H ₄ C ₂ H ₅ ) is used as a liquid reaction material, and RuO ₂ is formed using oxygen or nitrous oxide as an oxidizing agent,
The method according to claim 4, wherein the film is formed by depositing Ru by thermally decomposing only Ru (C ₅ H ₄ C ₂ H ₅ ). 9. The high dielectric memory according to claim 5, wherein said high dielectric memory has a structure of a metal electrode film / a high dielectric insulating film / a metal electrode film (MIM) and constitutes a high dielectric capacitor.
The method described in. 10. The high dielectric capacitor has a structure of a metal upper electrode film / high dielectric insulating film / metal lower electrode film, wherein the metal upper electrode film / high dielectric insulating film / metal lower electrode film is , Ru / Ta ₂ O ₅ / RuO ₂ , Ru / Ta ₂ O ₅ / R
u, Ru / Ta ₂ O ₅ / RuO ₂ .Ru, RuO ₂ / Ta ₂
The method according to claim 9, wherein the method has a structure of O ₅ / Ru or RuO ₂ / Ta ₂ O ₅ / RuO ₂ .Ru. 11. The method according to claim 10, further comprising an adhesive layer made of Ti, TiN or TaN at an interface between the silicon substrate and the metal lower electrode film. 12. The method according to claim 4, wherein the film is formed at a temperature in the range of 400 to 700 ° C. 13. The gas head is connected to a high-frequency power supply, and can supply a chlorine-based gas for cleaning into a furnace using an oxidizing gas supply path, and generates a plasma discharge in the furnace. 2. The method according to claim 1, wherein
3. The chemical vapor deposition apparatus according to claim 1. 14. The high frequency power supply has a frequency of 13.56 MHZ.
The chlorine-based gas is ClF ₃ or more.
An apparatus according to claim 1.