JP4659377B2 - Insulating film formation method - Google Patents

Description

The present invention relates to the formation how the applied insulating film in the case of forming the insulating film in a manufacturing process or the like for a display device, for example a semiconductor device or a liquid crystal display device such as a semiconductor integrated circuit device.

  Conventionally, in a manufacturing process of a semiconductor device, a liquid crystal display device, etc., an insulating film is formed on a substrate to be processed using a parallel plate type high frequency plasma CVD (Plasma Enhanced Chemical Vapor Deposition) apparatus using an organic silicon compound as a process gas. Methods of forming are known.

  The parallel plate type high-frequency plasma CVD apparatus includes a vacuum chamber, a high-frequency power source, a high-frequency electrode, a ground electrode, and the like. The vacuum chamber has a gas introduction part for introducing a mixed gas of an organic silicon compound gas and oxygen.

  When an insulating film is formed using this parallel plate type high-frequency plasma CVD apparatus, the following is performed. Organosilicon compound gas and oxygen gas are introduced into the vacuum chamber through the gas introduction part. By supplying high frequency power of 13.56 MHz from the high frequency power source to the high frequency electrode, plasma is generated in the vacuum chamber. By doing so, the organosilicon compound is decomposed by the plasma, and a silicon oxide film using the organosilicon compound as a material is formed on the substrate to be processed (see, for example, Patent Document 1).

  However, in the parallel plate type high-frequency plasma CVD apparatus as described above, the plasma generated in the vacuum chamber spreads to a region where the substrate to be processed is disposed, so that the surface of the substrate to be processed and the substrate to be processed are insulated. There is a problem that ion damage is liable to occur at the interface with the film. That is, when the plasma spreads to a region where the substrate to be processed is disposed, the substrate to be processed comes into contact with high-energy electrons, so that a sheath electric field that tends to increase according to the energy of electrons increases. As the sheath electric field increases, the energy of ions incident on the substrate to be processed increases accordingly. As a result, ion damage is likely to occur on the surface of the substrate to be processed and the interface between the substrate to be processed and the insulating film. End up.

  In recent years, a method for forming an insulating film on a substrate to be processed by using an insulating film forming apparatus that generates surface wave plasma to localize the plasma has been proposed. In this case, silane gas (monosilane gas or the like) is generally used as the process gas.

  As an insulating film forming apparatus, an apparatus provided with a vacuum chamber, a dielectric plate, a radial line slot antenna, a microwave generator for generating 8.3 GHz microwave, and the like are known. The vacuum chamber has a first gas introduction part for introducing a mixed gas of krypton gas and oxygen gas, and a second gas introduction part for introducing silane gas. The dielectric plate forms part of the wall of the vacuum chamber. The radial line slot antenna is provided along the dielectric plate. The first gas introduction part is provided closer to the radial line slot antenna than the second gas introduction part. The position of the second gas introduction part is set so that silane gas is introduced from a region where the electron temperature is 1 eV or less.

  When an insulating film is formed using this insulating film forming apparatus, the following is performed. A mixed gas of krypton gas and oxygen gas is introduced into the vacuum chamber through the first gas introduction unit. The electromagnetic wave radiated from the radial line slot antenna is transmitted through the dielectric plate into the vacuum chamber. As a result, oxygen and krypton are excited to generate surface wave plasma in the vacuum chamber. Then, oxygen radicals are generated by this surface wave plasma. Silane gas is introduced from the second gas introduction part, and the silane gas is decomposed and reacted by oxygen radicals. Thereby, a silicon oxide film as an insulating film is formed on the substrate to be processed (see, for example, Non-Patent Document 1).

  Other insulating film forming apparatuses include a process chamber, a dielectric partition, a shower plate for plasma excitation gas, a shower plate for process gas, a radial line slot antenna, and a magnetron that generates 2.45 GHz microwaves. What you have is known. The dielectric partition is provided below the radial line slot antenna. The plasma excitation gas shower plate is provided below the dielectric partition. The process gas shower plate is provided below the plasma excited gas shower plate.

This insulating film forming apparatus is used as follows. A rare gas as a plasma excitation gas is introduced into the process chamber through a plurality of openings formed in the plasma excitation gas shower plate. Microwaves radiated from the radial line slot antenna are introduced into the process chamber through a plasma excitation gas shower plate. Thereby, noble gas is excited and plasma is generated. Process gas is supplied through a plurality of openings formed in the process gas shower plate. As a result, the process gas reacts with the plasma, and a predetermined process is performed on the substrate to be processed (see, for example, Patent Document 2).
On the other hand, metal oxides such as hafnium oxide and zirconium oxide are attracting attention as materials for insulating films because of their higher dielectric constant than silicon oxide. As a method of forming a film made of a metal oxide such as hafnium oxide or zirconium oxide (hereinafter referred to as a metal oxide film), a metal organic chemical vapor deposition method (MOCVD method), a sputtering method, or an atomic layer deposition method ( ALD method) is known.

  However, in the metal organic chemical vapor deposition method, since a metal organic compound gas as a raw material is decomposed on a substrate to be processed heated to 500 ° C. to 700 ° C. to grow a film, it is relatively unlike a glass substrate or a plastic substrate. It is difficult to apply to a substrate to be processed having a low melting point. Further, in the sputtering method, since high-speed neutral particles that have rebounded from the target collide with the substrate to be processed, the substrate to be processed is easily damaged. Furthermore, in the atomic layer deposition method, the atomic layers are deposited one by one, so that the film formation rate is very slow.

In recent years, a method for forming a zirconium oxide film using plasma has been proposed for such problems. First, a mixed gas of tetrapropoxyzirconium (Zr (OC ₃ H ₇ ) ₄ ) gas, oxygen gas, and argon gas is prepared. At this time, the ratio of oxygen gas to argon gas in the mixed gas is set to 1: 5. A mixed gas is introduced into a chamber provided with a substrate to be processed. Plasma is generated in the chamber, and Zr (OC ₃ H ₇ ) ₄ gas and oxygen gas are plasma-discharged. Thereby, a zirconium oxide film is formed on the substrate to be processed. (For example, refer nonpatent literature 2.).
JP-A-5-345831 (paragraphs 0013 to 0016, FIG. 1) JP 2002-299241 A (paragraphs 0033 to 0049, FIG. 1) Hiroki Tanaka et al. “High-Quality Silicon Oxide Film Formed by Diffusion Region Plasma Enhanced Chemical Vapor Deposition and Oxygen Radical Treatment Using Microwave-Excited High-Density Plasma” Jpn. J. Appl. Phys. Vol.42 (2003) pp1911- 1915 Junji Morioka and two others, “Formation of high-permittivity zirconium oxide film by plasma CVD using metal organic material as a precursor”, January 29, 2003, 20th “Plasma Processing Study Group” Physics Society Plasma Electronics Subcommittee Sponsored Proceedings, p317-p318

  By the way, when an organic silicon compound gas is used as a process gas, a silicon oxide film having a good coverage is easily obtained as compared with the case where a silane gas is used. This is because the organic silicon compound has a larger molecular volume than silane. Therefore, the intermediate product obtained by decomposing the organosilicon compound by plasma also has a relatively large molecular volume, and it migrates on the surface of the substrate to be processed due to its steric effect, and adheres relatively uniformly to the surface of the substrate to be processed. To do. Therefore, a silicon oxide film with good coverage is obtained.

  However, since the organosilicon compound contains an alkyl group or the like in its skeleton, when the organosilicon compound is excessively decomposed, carbon atoms contained in the carbon skeleton portion are mixed as impurities into the formed silicon oxide film. It becomes easy. That is, there is a problem that the harmful effect caused by excessive decomposition is greater than that of the silane gas used in the technique described in Non-Patent Document 1.

  On the other hand, the technique described in Non-Patent Document 2 has a problem that oxygen vacancies are likely to occur in the formed metal oxide film because the partial pressure of oxygen gas in the mixed gas is kept low.

The present invention has been made based on such a situation, and it is possible to satisfactorily provide an insulating film on a substrate to be processed while suppressing damage to the substrate to be processed and the insulating film formed on the substrate to be processed. forming an object to provide a form how the insulating film that can.

According to a first aspect of the present invention, there is provided a method for forming an insulating film comprising: a step of disposing a substrate to be processed inside a processing container having an electromagnetic wave incident surface on which electromagnetic waves are incident; a first gas containing at least one, a step of introducing into the interior of the processing container of the vacuum from the distance is less than 10mm position from the electromagnetic wave incident face, a second gas containing an organic silicon compound, the electromagnetic wave A step of separating the first gas from the annular lower gas introduction pipe which is provided at a position where the distance from the incident surface is 10 mm or more and which is larger than the substrate to be processed, and introducing the gas into the processing container; by incident electromagnetic waves from the electromagnetic wave incident face into the interior of the container, La of the first gas cause surface wave plasma by said first gas adjacent the electromagnetic wave incident face inside of the processing container Without generating a shower head between the introduction position of the first gas and the introduction position of the second gas, and the radicals are diffused in a vacuum and flow of the second gas. A step of depositing silicon oxide on the substrate to be processed by reaching the atmosphere and reacting with the second gas; and an insulating film having a stable film thickness by directly heating the lower gas introduction tube to 80 ° C. to 200 ° C. It is characterized by forming.

In the method for forming an insulating film according to the second aspect of the present invention, the first gas contains at least one rare gas of helium, neon, argon, krypton, and xenon. Furthermore, in the method for forming an insulating film according to the third aspect of the present invention, the flow rate of oxygen gas when the first gas contains oxygen gas and the oxygen gas is supplied into the processing container. However, it is set to be larger than the flow rate of the second gas when the second gas is introduced into the processing container.

  When electromagnetic waves are incident on the inside of the processing container from the electromagnetic wave incident surface, the first gas and the second gas are excited to generate plasma, and the electron density in the plasma near the electromagnetic wave incident surface increases. As the electron density in the plasma near the electromagnetic wave incident surface increases, it becomes difficult for the electromagnetic wave to propagate through the plasma and attenuates in the plasma. Therefore, the electromagnetic wave does not reach the region away from the electromagnetic wave incident surface, and the region where the first gas and the second gas are excited by the electromagnetic wave is limited to the vicinity of the electromagnetic wave incident surface. This state is a state in which surface wave plasma is generated.

  In other words, in a state where surface wave plasma is generated, a region where ionization of the compound occurs due to the energy of the electromagnetic wave is localized in the vicinity of the electromagnetic wave incident surface. That is, the state of the surface wave plasma varies depending on the distance from the electromagnetic wave incident surface. In the state where surface wave plasma is generated, the electric field of the sheath generated near the surface of the substrate to be processed is small. Therefore, the incident energy of ions on the substrate to be processed is low, and the substrate to be processed is less damaged by the ions.

  The boundary of the region where the surface wave plasma is generated is the interface between the electromagnetic wave incident surface (dielectric window) and the internal space of the processing container (the region where the first gas is supplied). In a state where surface wave plasma is generated, the region where the plasma energy is high, that is, the region where the electromagnetic wave reaches and directly excites the first and second gases can be known from the skin thickness. it can. The skin thickness indicates the distance from the electromagnetic wave incident surface to the position where the electric field of the electromagnetic wave attenuates to 1 / e, and the value depends on the electron density near the electromagnetic wave incident surface.

  That is, in a state where surface wave plasma is generated, high-density plasma is generated in a region where the distance from the electromagnetic wave incident surface is smaller than the skin thickness. Further, in a region where the distance from the electromagnetic wave incident surface is larger than the skin thickness (region outside the skin thickness), the electromagnetic wave is shielded by high-density plasma and does not reach, and oxygen radicals reach as a diffusion flow.

  Therefore, when surface wave plasma is generated inside the processing container and an insulating film is formed on the substrate to be processed disposed inside the processing container, the distance from the electromagnetic wave incident surface becomes larger than the skin thickness. If the second gas containing the organosilicon compound gas or the organometallic compound is supplied from any position, excessive decomposition of the organosilicon compound or the organometallic compound can be suppressed, and the oxygen radical and the organosilicon compound or the organometallic compound It is considered that an insulating film (silicon oxide film or metal oxide film) having a good film quality with few oxygen vacancies, uniform and excellent step coverage can be formed on the substrate to be processed.

The skin thickness δ can be obtained by the following equation (1).

ω: angular frequency of electromagnetic wave c: speed of light in vacuum (constant)
n _e: electron density n _C: Cutoff Density cutoff density n _C can be determined by the following equation (2).

ε ₀ : dielectric constant in vacuum (constant)
m _e : electron mass (constant)
ω: angular frequency of electromagnetic wave e: elementary charge (constant)
The dispersion relationship of the surface wave plasma is expressed by the following equation (3).

ω: angular frequency of electromagnetic wave c: speed of light in vacuum (constant)
ε _d : Dielectric constant of dielectric window ω _p : Angular frequency of plasma Angular frequency ω _p of plasma can be obtained by the following equation (4).

e: Elementary charge (constant)
n ₀ : electron density ε ₀ : dielectric constant in vacuum (constant)
m _e : electron mass (constant)
In order for the surface wave to propagate through the boundary surface between the electromagnetic wave incident surface (dielectric window) and the plasma, the denominator of the expression (3) needs to take a positive value. Therefore, when the relationship of the formula (4) is included, it is necessary to satisfy the relationship of the following formula (5).

n ₀ : electron density ε ₀ : dielectric constant in vacuum (constant)
m _e : electron mass (constant)
ε _d : dielectric constant of dielectric window e: elementary charge (constant)
ω: Angular frequency of electromagnetic waves Using the formula (5), because of the use of electromagnetic waves for industrial purposes in Japan, the maximum allowable value is used as a special case of the allowable value of electric field strength due to fundamental wave or spurious emission. Frequency (radio equipment regulation Article 65 and Ministry of Posts and Telecommunications Notification No. 257), 2.45 GHz, 5.8 GHz and 22.125 GHz, synthetic quartz (relative permittivity 3.8) and alumina (relative permittivity) When 9.9) is used, the electron density n ₀ necessary for the surface wave to propagate through the plasma boundary surface is obtained, and the skin thickness at that time is calculated as shown in Table 1. That is, when a dielectric window having a relative dielectric constant of 3.8 or more is used at a frequency of 2.45 GHz or more and a complete surface wave plasma state is obtained, the skin thickness is 10 mm or less.

  In the process using microwaves, the above-mentioned frequencies, that is, high-frequency power sources of 2.45 GHz, 5.8 GHz, and 22.125 GHz are often used, and quartz or alumina is generally used as the material of the dielectric window. is there. Therefore, if a dielectric window made of quartz is used and the skin thickness is δ or more when the frequency is 2.45 GHz, that is, 10 mm or more away from the electromagnetic wave incident surface, the electromagnetic wave is shielded by high-density plasma. Without it, it is thought that oxygen radicals arrive as a diffusion flow.

  In addition, the present inventors can suppress excessive decomposition of the organic silicon compound and the organometallic compound if the second gas is introduced into the processing container from a position where the electron temperature is 2 eV or less. I found out. FIG. 10 shows the relationship between the distance from the electromagnetic wave incident surface and the electron temperature. As shown in FIG. 10, even when the kind and partial pressure of the first gas for generating plasma are changed, the electron temperature is about 2 eV or less in the region away from the electromagnetic wave incident surface by 10 mm or more. It turns out that there is no contradiction with inference.

  Furthermore, the inventors of the present invention excessively decomposed the organosilicon compound or organometallic compound if the second gas is introduced into the processing container from a position where the electron density is reduced to 50% or less of the electromagnetic wave incident surface. I found out that it can be suppressed. FIG. 11 shows the relationship between the distance from the electromagnetic wave incident surface and the electron density. As shown in FIG. 11, even if the type and partial pressure of the first gas for generating plasma are changed, the electron density is 50% or less of the electromagnetic wave incident surface in a region separated by 10 mm or more from the electromagnetic wave incident surface. It is decreasing and it turns out that it is not inconsistent with the above reasoning.

  From these results, the present inventors introduce a second gas into the processing vessel from a position 10 mm or more away from the electromagnetic wave incident surface, thereby reducing oxygen deficiency, being uniform, and having excellent step coverage. It has been found that an insulating film (silicon oxide film or metal oxide film) can be formed on a substrate to be processed with little ion damage.

  As described above, the insulating film forming methods according to the first and second embodiments of the present invention are insulating film forming methods for forming an insulating film on a substrate to be processed using surface wave plasma. The gas and the second gas are separated and supplied into the processing container. Specifically, the first gas containing at least one of the rare gas and the oxygen gas is introduced into the processing container from a position where the distance from the electromagnetic wave incident surface is less than 10 mm, and the second gas containing the organic silicon compound is included. The gas is introduced into the processing container from a position where the distance from the electromagnetic wave incident surface is 10 mm or more.

  Thus, by using surface wave plasma, a region having high plasma energy can be localized at a position away from the substrate to be processed. Thereby, since the sheath electric field in the vicinity of the substrate to be processed is reduced, the energy of ions incident on the substrate to be processed is also reduced. Therefore, ion damage given to the substrate to be processed and the insulating film formed on the substrate to be processed can be suppressed.

  Moreover, the first gas is introduced into the processing container from a position where the distance from the electromagnetic wave incident surface is less than 10 mm. In a region where the distance from the electromagnetic wave incident surface is less than 10 mm, electrons are directly accelerated by the electric field due to the electromagnetic waves, and thus the energy of the electrons is large. Therefore, oxygen radicals can be efficiently generated in the processing container.

  Furthermore, the second gas is introduced into the processing container from a position where the distance from the electromagnetic wave incident surface is 10 mm or more. In the region where the distance from the electromagnetic wave incident surface is 10 mm or more, the electromagnetic wave is shielded by the high-density plasma, so that the organic silicon compound and the organometallic compound can be prevented from being excessively decomposed. Therefore, it is possible to form an insulating film having a good film quality that has few oxygen vacancies, is uniform, and has excellent step coverage on the substrate to be processed.

  In most cases, the electron temperature is 2 eV or less at a position 10 mm or more away from the electromagnetic wave incident surface. Thus, in the region where the electron temperature is low, that is, in the region where the energy of electrons is low and excessive decomposition due to the collision of electrons of the organosilicon compound or organometallic compound is suppressed, the oxygen radical and the organosilicon compound that reach the diffusion flow Alternatively, by reacting with an organometallic compound and depositing an insulating film on the substrate to be processed, there is almost no damage to the substrate to be processed, there is little oxygen deficiency, it is uniform, and the film quality is excellent with excellent step coverage. An insulating film can be formed.

  Further, in most cases, the electron density is reduced to 50% or less of the incident surface of the electromagnetic wave at a position 10 mm or more away from the electromagnetic wave incident surface. Thus, oxygen that reaches as a diffusion flow in a region where the electron density is low, that is, a region where collision frequency between electrons and process gas is low and excessive decomposition due to collision of electrons of the organosilicon compound or organometallic compound is suppressed. By reacting radicals with an organosilicon compound or organometallic compound and depositing an insulating film on the substrate to be processed, there is little damage to the substrate to be processed, oxygen vacancies are small, uniform, and step coverage is achieved. An insulating film having excellent film quality can be formed.

It should be noted that the method for forming an insulating film according to the first and second embodiments of the present invention and an insulating film forming apparatus according to a reference example of the present invention described later (the insulating film forming apparatus according to the embodiment of the present invention) It is understood that an insulating film forming apparatus according to a reference example of the present invention is shown in any claim because the insulating film forming apparatus is not described in any claim). As the “processing substrate”, for example, a substrate such as a glass substrate, a quartz glass substrate, a ceramic substrate, a resin substrate, or a silicon wafer can be used. In addition, as the “substrate to be processed”, a semiconductor layer such as single crystal silicon, polycrystalline silicon, microcrystalline silicon, or amorphous silicon formed on the substrate as described above by laser crystallization, solid phase crystallization, or the like. You may use what was formed. Furthermore, as a “substrate to be processed”, a semiconductor layer and an insulating film are stacked in any order on the above-described substrate, or a semiconductor layer and an insulating film are not in any order on the above-described substrate. A circuit element having a stacked portion, a part in which a part of the circuit element is formed, or the like may be used.

  When the insulating film forming method according to the first aspect of the present invention is carried out, the second gas is an organosilicon compound such as tetraalkoxysilane, vinylalkoxysilane, alkyltrialkoxysilane, phenyltrialkoxysilane, polymethyl. It preferably contains one or more of disiloxane and polymethylcyclotetrasiloxane. In this way, a silicon oxide film with good film quality can be formed on the substrate.

  On the other hand, when realizing the method for forming an insulating film according to the second aspect of the present invention, the second gas is trimethylaluminum, triethylaluminum, tetrapropoxyzirconium, pentaethoxytantalum, or tetrapropoxyhafnium as an organometallic compound. It is preferable that any one of them is included. By selecting trimethylaluminum or triethylaluminum, an aluminum oxide film can be formed on the substrate to be processed. By selecting tetrapropoxyzirconium, a zirconium oxide film can be formed on the substrate to be processed. By selecting pentaethoxytantalum, a tantalum oxide film can be formed on the substrate to be processed. By selecting tetrapropoxy hafnium, a hafnium oxide film can be formed on the substrate to be processed. Further, hafnium oxide and zirconium oxide have a dielectric constant higher than that of silicon oxide. Therefore, by selecting tetrapropoxy hafnium or tetrapropoxy zirconium, it is possible to form an insulating film having better insulating properties than the silicon oxide film.

  When carrying out the method for forming an insulating film according to the first and second aspects of the present invention, the first gas contains at least one rare gas of helium, neon, argon, krypton, or xenon. It is preferable. Most organic silicon compounds and organometallic compounds contain oxygen in the constituent elements. Therefore, the first gas does not necessarily include oxygen gas. By containing at least one rare gas of helium, neon, argon, krypton, or xenon, oxygen can be contained in the processing container. By generating radicals, an insulating film can be formed on the substrate to be processed.

  However, as the first gas, it is more preferable to use a gas containing at least one rare gas of helium, neon, argon, krypton, or xenon and oxygen gas. By doing so, it is possible to generate a large amount of oxygen radicals in the processing container and to form an insulating film with few oxygen vacancies on the substrate to be processed.

  When the first gas contains oxygen gas, the flow rate when supplying the oxygen gas into the processing container is set to be higher than the flow rate when supplying the second gas into the processing container. It is preferable to do this. By doing in this way, oxygen radicals can exist more than the second gas below the position where the second gas is introduced. Therefore, since the oxidation of silicon atoms in the organic silicon compound and metal atoms in the organometallic oxide is promoted, a high-quality oxide film with fewer oxygen vacancies can be formed.

  An insulating film forming apparatus according to a third aspect of the present invention has an electromagnetic wave incident surface on which an electromagnetic wave is incident, a processing container in which a substrate to be processed can be disposed, and at least one of a rare gas and an oxygen gas A first gas introduction section for introducing a first gas containing one into the processing container; a first gas introduction system provided in the processing container; and a first gas containing an organosilicon compound or an organometallic compound. A second gas introduction part for introducing the second gas into the processing container, and a second gas introduction system provided in the processing container, the first gas introduction part and the electromagnetic wave incident And the distance between the second gas introduction part and the electromagnetic wave incident surface is set to 10 mm or more, and the distance between the surface and the inside of the processing container is set to be less than 10 mm. Surface wave plasm by the first and second gases There can be generated.

  In the insulating film forming apparatus according to the third aspect of the present invention, the distance between the first gas introduction part for introducing the first gas and the electromagnetic wave incident surface is less than 10 mm, and the second gas is introduced. Therefore, the distance between the second gas introduction part and the electromagnetic wave incident surface is set to 10 mm or more. In this way, the first gas can be supplied to a region where the plasma density is relatively high. Therefore, oxygen radicals can be efficiently generated in the processing container. In addition, the second gas containing an organosilicon compound or an organometallic compound can be supplied to a region where electromagnetic waves are shielded by high-density plasma and do not reach. Therefore, excessive decomposition of the organosilicon compound or the organometallic compound due to the collision of electrons can be suppressed.

  Therefore, by using the insulating film forming apparatus according to the third embodiment of the present invention, the substrate to be processed has a high quality insulating film with few oxygen vacancies, good film quality, and excellent step coverage. Can be formed.

  By the way, in order to generate oxygen radicals more efficiently in the processing container, in the region near the dielectric member, particularly in the region where the electromagnetic wave reaches and directly excites the gas even in the surface wave plasma state, that is, the skin thickness. It is desirable to supply oxygen to the area shown. That is, when using the 1st gas containing oxygen gas, it is preferable to supply this 1st gas in the area | region shown by skin thickness.

  Therefore, when the insulating film forming method according to the third embodiment of the present invention is carried out, the first gas containing oxygen gas is used, and the distance between the first gas introduction part and the electromagnetic wave incident surface is the surface. It is preferable to provide the first gas introduction part in a region where the skin thickness of the wave plasma becomes smaller or to form the first gas introduction part integrally with the dielectric member. By doing so, oxygen can be supplied to a region where electrons are directly accelerated by an electric field generated by electromagnetic waves. Therefore, the first gas supplied from the first gas introduction system is placed near the dielectric member. It can be efficiently decomposed to generate oxygen radicals efficiently. In addition, oxygen radicals generated in the vicinity of the dielectric member by the first gas supplied from the first gas introduction system can be sufficiently reacted with the second gas supplied from the second gas introduction system. Therefore, an insulating film with few oxygen vacancies, a uniform, and excellent film quality with excellent step coverage can be formed at a good film formation rate.

  In addition, organosilicon compounds and organometallic compounds often have higher boiling points than monosilane and the like. Therefore, when an insulating film is formed using the insulating film forming apparatus described in Patent Document 2, if a compound having a high boiling point such as an organic silicon compound or an organometallic compound is used as a process gas, a part of the process gas is generated. It may liquefy and block some of the plurality of gas discharge openings formed in the process gas shower plate. As described above, when the process gas shower plate is closed, the process gas may not be stably supplied into the processing container, or the supply thereof may become uneven.

  Therefore, in the insulating film forming apparatus described in Patent Document 2, the supply amount of the organic silicon compound gas tends to be non-uniform. Since the formation rate of the insulating film is related to the amount of process gas supplied, if the process gas is not stably supplied into the processing container or the supply amount is non-uniform, the uniformity of the film thickness is It will be damaged.

  Therefore, when the insulating film forming method according to the third embodiment of the present invention is carried out, the second gas introduction system preferably includes a heating means. By doing so, the second gas containing the organic silicon compound or the organometallic compound can be kept at a predetermined temperature such that the second gas is uniformly introduced from the gas introduction part of the second gas introduction system.

  When the second gas introduction system includes a heating unit, it is preferable to employ a heating unit that can hold the substrate to be processed at a temperature of about 80 ° C. to 200 ° C. By holding the second gas introduction part at a temperature of 80 ° C. to 200 ° C., even when a gas having a high boiling point such as an organic silicon compound or an organometallic compound is used as the second gas, the liquefaction of the second gas is performed. The variation in the gas supply amount due to is suppressed, and an insulating film having a stable film thickness can be formed.

  The heating means is preferably provided outside the processing vessel, for example, in a state of being thermally connected to the second gas introduction system. By doing so, the second gas introduction system can be heated without complicating the structure. The heating means may be configured, for example, by providing a circulation path in the structural wall of the second gas introduction system and circulating a high-temperature fluid (high-temperature gas or high-temperature liquid) through this circulation path. According to this configuration, heat energy can be quickly transmitted to the entire second gas introduction system by circulating the high-temperature fluid in the structural wall. Therefore, the second gas introduction system can be heated evenly. As the heating means, for example, a heater can be used, but is not limited thereto.

  Furthermore, in the insulating film forming apparatus described in Patent Document 2, the process gas is introduced into the process gas shower plate from one end side of the process gas shower plate, and flows through the process gas shower plate. The process gas shower plate is configured to discharge gas from a plurality of gas discharge openings. Therefore, the amount of the process gas released from the plurality of gas discharge openings formed in the shower plate is large at one end side where the organic silicon compound gas is introduced, and decreases as the distance from the one end side increases. As described above, if the process gas is not stably supplied into the processing container or the supply amount thereof is not uniform, the uniformity of the film thickness is impaired.

  Therefore, when implementing the method for forming an insulating film according to the third aspect of the present invention, for example, the second gas introduction part is a shower plate having a plurality of gas ejection ports, and a plurality of gas ejection ports are formed. The opening ratio per unit area is such that the conductance (reciprocal of physical resistance) of the gas outlet to the gas flow is small on the upstream side of the gas flow in the shower plate, and this is the downstream of the gas flow in the shower plate. It is preferable to set the conductance of the gas outlet to the gas flow to be large. Specifically, for example, the opening ratio per unit area of the plurality of gas outlets may be set so that the upstream side of the gas flow in the shower plate is small and the downstream side of the gas flow is large. More preferably, the conductance of the gas outlet (opening ratio per unit area of the gas outlet) has a substantially uniform distribution of the supply amount of the second gas supplied from the shower plate to the inside of the processing container. It is good to set as follows. By doing so, the second gas can be supplied into the processing container with good uniformity, so that an insulating film with good uniformity can be formed on the substrate to be processed.

  Further, when the second gas introduction part is a shower plate partitioned by a partition wall having an opening, the conductance of the partition wall with respect to the gas flow is large on the upstream side of the gas flow in the shower plate, and the shower plate has a large conductance. A plurality of partition walls for adjusting the gas flow are provided in the shower plate so that the conductance of the partition walls with respect to the gas flow is reduced on the downstream side of the gas flow. Thus, it is preferable to provide gas outlets, respectively. Specifically, for example, the plurality of partition walls may be set so as to be lower on the upstream side of the gas flow in the shower plate and higher on the downstream side of the gas flow. More preferably, the size and position of the partition are set so that the distribution of the supply amount of the second gas supplied from the shower plate is substantially uniform. By doing so, since the flow of the second gas in the shower plate is controlled, it is possible to supply the second gas into the processing container with good uniformity, and the uniformity in the shape of the substrate to be processed. Can be formed.

  Further, when the second gas introduction part is a shower plate having a plurality of gas ejection ports, a plurality of first gas chambers having a gas introduction port into which the second gas is introduced, and a plurality of gas outlets are provided inside the shower plate. And a second gas chamber having a gas jet port of the first gas chamber and a second gas chamber connected via a diffusion plate having a plurality of openings for adjusting the gas flow between the first gas chamber and the second gas chamber. In addition, the opening ratio per unit area of the plurality of opening portions is determined such that the conductance of the opening portion with respect to the gas flow is small on the upstream side of the gas flow in the shower plate and the downstream side of the gas flow in the shower plate is It is preferable to set the conductance of the opening with respect to the gas flow to be large. Specifically, for example, the opening ratio per unit area of the plurality of openings may be set so that the upstream side of the gas flow in the shower plate is small and the downstream side of the gas flow is large. More preferably, the conductance of the opening (opening ratio per unit area of the opening) is such that the distribution of the supply amount of the second gas supplied from the shower plate into the processing container is substantially uniform. It is good to set. By doing so, since the flow of the second gas in the shower plate is controlled, it is possible to supply the second gas into the processing container with good uniformity, and the uniformity in the shape of the substrate to be processed. Can be formed.

  Further, when the insulating film forming apparatus according to the third embodiment of the present invention is implemented, the attachment portion where the second gas introduction system is attached to the processing container may be formed of a dielectric. By adopting such a configuration, the second gas introduction part is changed to an electromagnetic field or plasma in a transient state until the plasma at the initial stage of discharge reaches a surface wave plasma state as compared with the case where a conductor such as metal is used. The effect on the plasma can be reduced and stable plasma discharge can be realized.

  Furthermore, when the insulating film forming apparatus according to the third embodiment of the present invention is implemented, the antenna preferably has one or more waveguide slot antennas. By adopting such a configuration, an antenna that can withstand high power with little dielectric loss can be obtained, so that the size of the insulating film forming apparatus can be easily increased. In an insulating film forming apparatus that forms an insulating film on a large substrate applied to a large liquid crystal display device, a plurality of waveguide slot antennas are arranged side by side so as to face the outer surface of the dielectric member. More preferably, it is provided. The antenna is not limited to the one having a waveguide slot antenna, and any antenna that can radiate electromagnetic waves toward the processing container may be used.

A first embodiment of the present invention will be described below with reference to FIGS. In this embodiment, one embodiment of a method for forming the insulating film of the present invention, and will be described with the insulating film forming equipment of Example of the present invention.

  FIG. 1 shows an example of an insulating film forming apparatus. The insulating film forming apparatus 1 of this embodiment includes a vacuum vessel 2 as a processing vessel, one or more, for example, nine dielectric members 3, a substrate support 4, a gas discharge system 5, and an upper gas as a first gas introduction system. An introduction system 6, a lower gas introduction system 7 as a second gas introduction system, a high-frequency power source 8, a waveguide 9, an antenna having one or more, for example, nine waveguide slot antennas 10, and a heating means 11 are provided. I have.

  The vacuum container 2 has an upper wall 2a, a bottom wall 2b, and a peripheral wall 2c that connects the peripheral edge of the upper wall 2a and the peripheral edge of the bottom wall 2b, and the inside can be decompressed to a vacuum state or the vicinity thereof. It is formed with possible strength. As a material for forming the upper wall 2a, the bottom wall 2b, and the peripheral wall 2c, for example, a metal material such as aluminum can be used.

  A dielectric member 3 is provided on the upper wall 2 a so as to constitute a part of the wall of the vacuum vessel 2. The dielectric member 3 is also formed with such a strength that the inside of the vacuum vessel 2 can be depressurized to a vacuum state or the vicinity thereof. As a dielectric material for forming the dielectric member 3, for example, synthetic quartz or the like can be used.

  Specifically, as shown in FIGS. 1 and 2, the upper wall 2 a has one or more, for example, nine openings 12. Each of these openings 12 forms an elongated space having a substantially T-shaped cross section. These openings 12 are provided in parallel with each other at a predetermined interval. One or more, for example, nine dielectric members 3 are each an elongated member having a substantially T-shaped cross section that fits into the opening 12. These dielectric members 3 are fitted in the corresponding openings 12 to close the openings 12 in an airtight manner. That is, a plurality of dielectric members 3 are arranged on the upper wall 2a of the vacuum vessel 2 so as to constitute a part of the wall of the vacuum vessel 2. The upper wall 2 a is a part of the wall of the vacuum vessel 2 and also functions as a beam that supports the dielectric member 3. Hereinafter, the dielectric member is referred to as a dielectric window 3.

  The vacuum vessel 2 has a sealing mechanism that seals between the upper wall 2a and the dielectric window 3 (not shown). The sealing mechanism includes, for example, a groove provided along the circumferential direction of the wall defining the opening 12 and an O-ring provided along the groove. By this sealing mechanism, a gap between the wall defining the opening 12 and the dielectric window 3 is sealed.

  Inside the vacuum vessel 2, the substrate support 4 for supporting the substrate to be processed 100 is provided. In the present embodiment, the arrangement position of the substrate support 4 is set so that the substrate 100 to be processed is held at a position 25 mm below a gas jet port 22a described later, for example.

  As the high frequency power source 8, for example, a power source of 2.45 GHz can be used. A plurality of waveguide slot antennas 10 are provided above the vacuum vessel 2 so as to correspond to the plurality of dielectric windows 3. Each of these waveguide slot antennas 10 is provided with a slit-like opening 10a in a part of a tube wall, and radiates electromagnetic waves by using electromagnetic coupling generated in the vicinity of the opening 10a. Each functions as an antenna. The plurality of waveguide slot antennas 10 are arranged side by side so as to face the outer surfaces of the plurality of dielectric windows 3. Adjacent waveguide slot antennas 10 are connected to each other.

  Since the waveguide slot antenna 10 is generally made of metal, the waveguide slot antenna 10 has features that it has less dielectric loss and higher resistance to large power than an antenna formed of a dielectric. In addition, the waveguide slot antenna 10 is suitable for an insulating film forming apparatus for a large substrate because the structure is simple and the design of radiation characteristics can be performed relatively accurately. In particular, the insulating film forming apparatus 1 of this embodiment in which a plurality of waveguide slot antennas 10 are arranged side by side is suitable for forming an insulating film on a rectangular substrate having a large area used for a large liquid crystal display device or the like. It is.

  One of the plurality of waveguide slot antennas 10, for example, the waveguide slot antenna 10 closest to the high frequency power supply 8 is connected to the high frequency power supply 8 through the waveguide 9. As a result, the electromagnetic wave generated by the high frequency power supply 8 is guided to each waveguide slot antenna 10 by the waveguide 9. That is, in the insulating film forming apparatus 1, the electromagnetic wave guided to the waveguide slot antenna 10 passes through the dielectric window 3 and enters the vacuum vessel 2. Therefore, the inner surface of the dielectric window 3 becomes the electromagnetic wave incident surface F.

  The vacuum vessel 2 is provided with the gas discharge system 5, the upper gas introduction system 6, and the lower gas introduction system 7. The gas discharge system 5 includes a gas discharge unit 5a provided in the vacuum vessel 2 so as to communicate with the inside of the vacuum vessel 2, a vacuum exhaust system 5b, and the like. As the vacuum exhaust system 5b, for example, a turbo molecular pump or the like can be used. By operating the vacuum exhaust system 5b, the inside of the vacuum vessel 2 can be exhausted until a predetermined degree of vacuum is reached.

  The upper gas introduction system 6 is for introducing a first gas containing at least one of a rare gas and an oxygen gas into the vacuum vessel 2. In the insulating film forming apparatus 1 of the present embodiment, the upper gas introduction system 6 has, for example, an upper gas introduction pipe 21 as a first gas introduction part.

  The upper gas introduction pipe 21 is formed of a metal such as aluminum, stainless steel, or titanium, or a dielectric such as silicon oxide, aluminum oxide, or aluminum nitride. In consideration of the influence of the upper gas introduction pipe 21 on the electromagnetic field and plasma, the upper gas introduction pipe 21 is preferably formed of a dielectric material. However, considering the processing when forming the tube, it is cheaper and easier to form the upper gas introduction tube 21 from a metal material. Therefore, when the upper gas introduction pipe 21 is formed of a metal material, an insulating film may be formed on the outer surface of the upper gas introduction pipe 21.

  As shown in FIG. 2, the upper gas introduction pipe 21 is provided along the inner surface of the upper wall 2 a (beam) of the vacuum vessel 2, avoiding the region where the dielectric window 3 is formed. Specifically, the upper gas introduction pipe 21 has a plurality of piping parts 21b and one extending part 21c. The plurality of piping parts 21b are connected in parallel to each other so as to follow the inner surface of the upper wall 2a (beam) of the vacuum vessel 2. The extending part 21c is piped so as to be orthogonal to the pipe parts 21b and communicates the pipe parts 21b with each other. Both ends of the extending portion 21 c extend outward of the vacuum vessel 2 through the peripheral wall 2 c of the vacuum vessel 2. A first gas cylinder (not shown) that accommodates the first gas can be detachably attached to both ends or one end of the extending portion 21c.

  A plurality of gas outlets 21a are provided in the pipe portions 21b at substantially equal intervals in the longitudinal direction. Therefore, the plurality of gas ejection ports 21a are located on substantially the same plane. These gas outlets 21a are provided at positions where the distance L1 from the electromagnetic wave incident surface F is smaller than the skin thickness δ of the surface wave plasma. In the present embodiment, the upper gas introduction pipe 21 is formed so that the distance L1 between the virtual plane F1 where the gas jet ports 21a are formed and the electromagnetic wave incident surface F is less than 10 mm, for example, 3 mm. By piping the upper gas introduction pipe 21, a plurality of gas outlets 21a are provided at a position 3 mm below the electromagnetic wave incident surface F (see FIG. 1).

  The lower gas introduction system 7 is for introducing a second gas containing an organosilicon compound or an organometallic compound into the vacuum vessel 2. In the insulating film forming apparatus 1 of the present embodiment, the lower gas introduction system 7 has, for example, a lower gas introduction pipe 22 as a second gas introduction part.

  The lower gas introduction pipe 22 is formed of a metal such as aluminum, stainless steel, or titanium, or a dielectric such as silicon oxide, aluminum oxide, or aluminum nitride, similarly to the upper gas introduction portion. By the way, in a transient state such as until the plasma at the initial stage of discharge reaches a surface wave plasma state, the electromagnetic wave reaches the lower gas introduction system 7. Therefore, when the lower gas introduction pipe 22 is formed of a metal material, the lower gas introduction system 7 may affect the electromagnetic field or plasma in the transient state. Therefore, considering the influence of the lower gas introduction tube 22 on the electromagnetic field and plasma, the lower gas introduction tube 22 is preferably formed of a dielectric material. When the lower gas introduction pipe 22 is formed of a metal material, an insulating film is preferably formed on the outer surface of the lower gas introduction pipe 22.

  As shown in FIG. 3, the lower gas introduction pipe 22 has an annular portion 22b and a pair of extending portions 22c. The annular portion 22 b is formed to be slightly larger than the outer periphery of the substrate 100 to be processed. Each extending portion 22c communicates with the annular portion 22b. One end of each extending portion 22 c extends outward of the vacuum vessel 2 via the peripheral wall 2 c of the vacuum vessel 2. A second gas cylinder (not shown) that accommodates the second gas can be detachably attached to one end of at least one of the extending portions 22c.

  The annular portion 22b is provided with a plurality of gas outlets 22a at substantially equal intervals in the longitudinal direction. These gas outlets 22a are provided at positions where the distance L2 from the electromagnetic wave incident surface F is larger than the skin thickness δ of the surface wave plasma. In the present embodiment, the lower gas introduction pipe 22 is formed such that the distance L2 between the virtual plane F2 in which the gas ejection ports 22a are formed and the electromagnetic wave incident surface F is 10 mm or more, for example, 30 mm. By disposing the lower gas introduction pipe 22, a plurality of gas outlets 22a are provided at a position 30 mm below the electromagnetic wave incident surface F (see FIG. 1).

  By the way, since the organic silicon compound gas and the organometallic compound gas contained in the second gas have a higher boiling point than monosilane or the like, they are easily liquefied. Therefore, in order to stably introduce the second gas into the vacuum vessel 2, it is desirable to keep the lower gas introduction system 7 at an appropriate temperature, that is, about 80 ° C. to 200 ° C. Therefore, in the insulating film forming apparatus 1 of this embodiment, the heating means 11 is provided in the lower gas introduction system 7. The heating unit 11 includes, for example, a heater 13.

  Specifically, the heater 13 is provided on the outer peripheral surface of each extending portion 22 c of the lower gas introduction pipe 22, for example. By doing in this way, heat can be transmitted to the whole lower gas introduction system 7 by heat conduction of the material which constitutes lower gas introduction pipe 22. Therefore, the lower gas introduction system 7 can be maintained at an appropriate temperature with a simple configuration as compared with the case where the heating means 11 is installed in the vacuum vessel 2. In the case where heat is transferred to the entire lower gas introduction system 7 by heat conduction of the material constituting the lower gas introduction pipe 22, the lower gas introduction pipe 22 has a heat conduction coefficient such as aluminum nitride. It is desirable to use a material having a large size.

  Next, an example of an insulating film forming method using the insulating film forming apparatus 1 will be described. In this embodiment, an example in which the insulating film 101 is formed on the substrate to be processed 100 using oxygen gas as the first gas and tetraethoxysilane which is a kind of tetraalkoxysilane as the second gas will be described. .

  The substrate to be processed 100 is disposed on the substrate support 4. The gas discharge system 5 is driven, and the inside of the vacuum vessel 2 is substantially evacuated. An oxygen gas is supplied from the upper gas introduction system 6 into the vacuum container 2 at a flow rate of 400 SCCM so that the gas pressure in the vacuum container 2 becomes 80 Pa, and a tetragonal gas is introduced from the lower gas introduction system 7 into the vacuum container 2. Ethoxysilane gas is supplied at a flow rate of 12 SCCM. At this time, the lower gas introduction system 7 is kept at an appropriate temperature (about 80 ° C. to 200 ° C.) by the heating means 11.

Turn on the high frequency power supply 8. As a result, an electromagnetic wave of 2.45 GHz is guided to the waveguide slot antenna 10 through the waveguide 9 and is irradiated from the waveguide slot antenna 10 toward the dielectric window 3 at a power density of 3 W / cm ^2. Become so.

  An electromagnetic wave of 2.45 GHz is irradiated into the vacuum vessel 2 through the dielectric window 3. Thereby, oxygen gas is excited to generate plasma, and the electron density in the plasma near the electromagnetic wave incident surface F increases. As the electron density in the plasma in the vicinity of the electromagnetic wave incident surface F increases, the electromagnetic wave becomes difficult to propagate in the plasma and attenuates in the plasma. Therefore, the electromagnetic wave does not reach the area away from the electromagnetic wave incident surface F. That is, surface wave plasma is generated. The oxygen gas is introduced into the vacuum container 2 from a position where the distance L1 to the electromagnetic wave incident surface F is 3 mm, that is, from a region where the distance L1 from the electromagnetic wave incident surface F is smaller than the skin thickness δ. In a state where wave plasma is generated, oxygen molecules are excited by high-density plasma, and oxygen radicals are efficiently generated.

  On the other hand, the tetraethoxysilane gas is introduced into the vacuum container 2 from a position where the distance L2 to the electromagnetic wave incident surface F is 30 mm, that is, from a region where the distance L2 from the electromagnetic wave incident surface F is larger than the skin thickness. Accordingly, since the electromagnetic wave is shielded by the high-density plasma and does not reach the region where the tetraethoxysilane gas is introduced into the vacuum vessel 2, it is possible to suppress the tetraethoxysilane from being excessively decomposed by the electromagnetic wave. Even when the distance L1 from the electromagnetic wave incident surface F is 30 mm, the oxygen radicals reach as a diffusion flow, so that tetraethoxysilane and oxygen radicals react efficiently, and the decomposition of tetraethoxysilane is accelerated. Is done. Accordingly, silicon oxide is deposited on the surface of the substrate 100 to be processed. Since tetraethoxysilane is a compound having a larger molecular volume than monosilane or the like, it migrates on the surface of the substrate 100 to be processed due to its steric effect and adheres relatively uniformly to the surface of the substrate 100 to be processed. Therefore, an insulating film (silicon oxide film) 101 with good film quality is formed on the substrate 100 to be processed.

Under such conditions, the insulating film 101 could be formed on the substrate 100 to be processed at a formation rate of 29 nm / min. The formed insulating film 101 had a leakage current of 2 × 10 ⁻¹⁰ A / cm ² and a fixed charge density of 2 × 10 ¹¹ / cm ² or less when an electric field of 2 MV / cm was applied. From this result, it was found that in the method for forming an insulating film of this embodiment, both the leakage current and the fixed charge density can be suppressed low, and the formation speed of the insulating film 101 is good.

  FIG. 10 shows the relationship between the electron temperature in the surface wave plasma and the distance from the electromagnetic wave incident surface F. The electron temperature changes abruptly when the distance from the electromagnetic wave incident surface F is about 10 mm because most of the electrons are in a region where the electromagnetic waves reach and electrons are directly excited (ie, a region within the skin thickness δ). This is considered to be due to the difference in electron temperature between the region where excitation is not performed (that is, the region outside the skin thickness δ). From this result, it was found that the skin thickness δ was about 10 mm at the maximum under the condition that the surface wave plasma state was maintained.

  FIG. 11 shows the relationship between the electron density in the surface wave plasma and the distance from the electromagnetic wave incident surface F. In the surface wave plasma, since the region excited by the electromagnetic wave is localized as described above, the electron density decreases as the distance from the electromagnetic wave incident surface F increases. Therefore, it has been found that the electron density at a position about 10 mm away from the electromagnetic wave incident surface F is 50% or less of the electron density at the electromagnetic wave incident surface F. From this result, it was also found that oxygen easily captures electrons, so that when oxygen is mixed, the electron density is lowered as compared with the case where plasma is generated with 100% argon.

  As described above, according to the insulating film forming method of the present embodiment, the process of disposing the substrate to be processed 100 inside the vacuum vessel 2 having the electromagnetic wave incident surface F on which the electromagnetic wave is incident, the rare gas and oxygen An oxygen gas as a first gas containing at least one of the gases is introduced into the vacuum vessel 2 from a position where the distance L1 from the electromagnetic wave incident surface F is less than 10 mm, and tetraethoxy as an organic silicon compound. Separating the second gas containing the silane gas from the first gas from a position where the distance L2 from the electromagnetic wave incident surface F is 10 mm or more and introducing the second gas into the vacuum container 2; By making an electromagnetic wave incident on the electromagnetic wave incident surface F, surface wave plasma is generated by the first and second gases inside the vacuum chamber 2, and silicon oxide is applied to the substrate 100 to be processed. And a step of product. Therefore, it is possible to satisfactorily form the insulating film 101 on the target substrate 100 while suppressing damage to the target substrate 100 and the insulating film 101 formed on the target substrate 100.

  In the insulating film forming method of the present embodiment, oxygen gas is used as the first gas and tetraethoxysilane gas is used as the second gas. However, the first and second gases are not limited to this. .

  The first gas is not limited to oxygen gas, and a gas including at least one of a rare gas and an oxygen gas may be employed. As the first gas, for example, oxygen, one or more rare gases of helium, neon, argon, krypton, and xenon and a mixed gas can be used. Helium, neon, argon, krypton, and xenon can be added to oxygen at a wide addition ratio from 10% to 99%, and the formation rate of the insulating film can be increased by the addition ratio.

  When a gas containing oxygen gas is employed as the first gas, the flow rate when supplying the oxygen gas into the vacuum vessel 2 and the flow rate when supplying the second gas into the vacuum vessel 2 are used. By increasing the amount, the oxidation of silicon atoms in the organosilicon compound and metal atoms in the organometallic oxide is promoted, so that a high-quality oxide film with fewer oxygen vacancies can be formed. .

  As the second gas, a gas containing an organosilicon compound or an organometallic oxide may be employed. By doing so, it is possible to satisfactorily form an insulating film on the substrate to be processed 100 while suppressing damage to the substrate to be processed 100 and the insulating film formed on the substrate to be processed 100.

  Examples of the organic silicon compound include, but are not limited to, tetraalkoxysilane, vinylalkoxysilane, alkyltrialkoxysilane, phenyltrialkoxysilane, polymethyldisiloxane, polymethylcyclotetrasiloxane, and the like. is not. Examples of the organometallic compound include, but are not limited to, trimethylaluminum, triethylaluminum, tetrapropoxyzirconium, pentaethoxytantalum, and tetrapropoxyhafnium.

  Moreover, according to the insulating film forming apparatus 1 of this embodiment, the vacuum vessel 2 in which the to-be-processed substrate 100 can be disposed, the high-frequency power source 8 for generating electromagnetic waves, and the electromagnetic waves toward the vacuum vessel 2. Dielectric having an radiating antenna and an electromagnetic wave incident surface F on the inner surface, provided in the vacuum vessel 2 so as to constitute a part of the wall of the vacuum vessel 2, and transmitting the electromagnetic wave radiated from the antenna to the inside of the vacuum vessel An upper portion provided in the vacuum vessel 2, having a body window 3 and an upper gas introduction pipe 21 for introducing oxygen gas as a first gas including at least one of a rare gas and oxygen gas into the vacuum vessel 2. A gas introduction system 6 and a lower gas introduction system 7 having a lower gas introduction pipe 22 for introducing a second gas containing an organosilicon compound or an organometallic compound into the vacuum vessel 2. It has. The upper gas introduction pipe 21 is provided on the electromagnetic wave incident surface F side of the lower gas introduction pipe 22, and the distance L2 between the gas jet port 22a of the lower gas introduction pipe 22 and the electromagnetic wave incidence surface F is 10 mm. They are separated. By using this insulating film forming apparatus 1, it is possible to satisfactorily form an insulating film on the target substrate 100 while suppressing damage to the target substrate 100 and the insulating film formed on the target substrate 100. be able to.

  In addition, since the insulating film forming apparatus 1 of the present embodiment has one or more waveguide slot antennas 10, the dielectric loss is small and can withstand high power. Further, since the plurality of waveguide slot antennas 10 are opposed to the outer surfaces of the plurality of dielectric windows 3 and arranged side by side, they are rectangular and have a large area used for a large liquid crystal display device or the like. An insulating film can be formed even on a substrate.

  Hereinafter, a second embodiment of the present invention will be described with reference to FIGS. In the present embodiment, an embodiment of the insulating film forming apparatus of the present invention will be described.

  The insulating film forming apparatus 1 of the present embodiment is different from the insulating film forming apparatus 1 described in the first embodiment in the lower gas introduction system 7 and the heating means 11, but the other configuration is the first described above. Since it is the same as the insulating film forming apparatus 1 of the embodiment, the overlapping description is omitted by attaching the same reference numerals to the drawings.

  The lower gas introduction system 7 is formed of a metal such as aluminum, stainless steel, or titanium, or a dielectric such as silicon oxide, aluminum oxide, or aluminum nitride. Note that it is desirable to use a dielectric as the material of the lower gas introduction system 7, as in the insulating film forming apparatus 1 of the first embodiment.

  The lower gas introduction system 7 has a shower plate 30 as a first gas introduction part (lower gas introduction part). As shown in FIG. 4, the shower plate 30 has a pair of plate members 31a and 31b facing each other and is formed in a flat box shape so that the second gas is circulated in the internal space S1. ing. The shower plate 30 has an opening 32 that opens the internal space S1. An opening 33 for opening the internal space S1 to the outside of the vacuum vessel 2 is formed in the peripheral wall 2c of the vacuum vessel 2. Therefore, the internal space S1 of the shower plate 30 is open to the outside of the vacuum vessel 2 through the walls of the opening 32 and the opening 33. The second gas is introduced into the internal space S <b> 1 of the shower plate 30 through the opening 33 and the opening 32. The shower plate 30 is formed in a size that divides the vacuum vessel 2 into an upper chamber and a lower chamber, and is provided so as to cover the substrate support 4 from above.

  As shown in FIG. 5, the shower plate 30 is provided with a large number of through holes 35 for allowing the first gas and oxygen radicals to flow between the upper chamber and the lower chamber. Further, the shower plate 30 is provided with a number of gas outlets 36 on the wall of the lower plate 31b.

  Further, the shower plate 30 is provided with heating means 11. The heating means 11 has a high-temperature medium circulator 34. The high temperature medium circulator 34 includes a pump 34a, a circulation path 34b, a heater (not shown), a high temperature fluid, and the like. For example, air, nitrogen, argon, krypton, xenon, or water, ethylene glycol, mineral oil, alkylbenzene, diarylalkane, triaryldialkane, diphenyl-diphenylether mixture, alkylbiphenyl, alkylnaphthalene Or the like.

  A circulation path 34 b for circulating a high-temperature fluid (high-temperature gas or high-temperature liquid) is provided inside the shower plate 30. The circulation path is isolated from the internal space S1 through which the first gas flows. In this high-temperature medium circulator 34, the high-temperature fluid is heated by the heater, and the pump 34a is operated to circulate the high-temperature fluid inside the shower plate 30, thereby allowing the lower gas introduction system 7 to reach about 80 ° C. to 200 ° C. It is configured to keep the temperature.

  When the lower gas introduction system 7 is heated by circulation of the high temperature medium in this way, heat energy is quickly transmitted to the lower gas introduction system 7 and the lower gas introduction system 7 can be heated evenly. Therefore, when the insulating film is formed using a gas containing an organic silicon compound gas or an organic metal compound gas, fluctuations in the gas supply amount due to the liquefaction of the organic silicon compound gas or the organic metal compound gas can be suppressed.

  As described above, if the insulating film forming apparatus 1 of the present embodiment is used, fluctuations in the gas supply amount due to the liquefaction of the organic silicon compound gas or the organometallic compound gas can be suppressed. When forming 101, good film thickness controllability and film thickness uniformity can be realized.

  Hereinafter, a third embodiment of the present invention will be described with reference to FIG. In the present embodiment, an embodiment of the insulating film forming apparatus of the present invention will be described.

  The insulating film forming apparatus 1 of the present embodiment is different from the insulating film forming apparatus 1 described in the first embodiment in the upper gas introduction system 6 and the lower gas introduction system 7, but the other configurations are the same as those described above. Since it is the same as that of the insulating film forming apparatus 1 of the first embodiment, the overlapping description is omitted by attaching the same reference numerals to the drawings.

  The upper gas introduction system 6 and the lower gas introduction system 7 are formed of a metal such as aluminum, stainless steel, or titanium, or a dielectric such as silicon oxide, aluminum oxide, or aluminum nitride. Note that it is desirable to use a dielectric as the material of the upper gas introduction system 6 and the lower gas introduction system 7, as in the insulating film forming apparatus 1 of the first embodiment.

  The upper gas introduction system 6 has an upper shower plate 40 as a first gas introduction part (upper gas introduction part). The upper shower plate 40 has a plate material 41 that covers the inner surface of the upper wall 2a of the vacuum vessel 2, and the first gas flows in the internal space S2 between the upper wall 2a of the vacuum vessel 2 and the plate material 41. It has come to be. The plate material 41 is connected to the upper wall 2a of the vacuum vessel 2 so as to keep the internal space S2 airtight. The internal space S <b> 2 of the upper shower plate 40 is open to the outside of the vacuum vessel 2 through an opening 42 formed in the peripheral wall 2 c of the vacuum vessel 2. From the opening 42, the first gas is introduced into the internal space S2 of the upper shower plate 40. In addition, a large number of gas outlets 43 are provided at substantially equal intervals on the plate material 41 of the upper shower plate 40.

  By the way, in the upper shower plate 40 as described above, a metal plate 41 such as aluminum, stainless steel, and titanium is grounded to the upper wall 2a of the vacuum vessel 2 and the gas outlet 43 is made sufficiently small. The plasma can be confined in the internal space S2. By doing so, it is possible to suppress the plasma from reaching the substrate to be processed 100 in a transient state until the plasma at the initial stage of the discharge reaches the surface wave plasma state, and the ultraviolet light with high energy contained in the plasma radiation light can be suppressed. It can be blocked by the upper shower plate 40. Therefore, the effect of suppressing damage to the substrate to be processed 100 can be enhanced.

  When the upper shower plate 40 is formed of a dielectric material such as silicon oxide, aluminum oxide, or aluminum nitride, depending on the shape of the upper shower plate 40, the gas pressure in the internal space S2 of the upper shower plate 40, etc., the plasma May occur in the upper part of the plate 41 and may occur in the lower part of the plate member 41.

  If the plasma is set to be generated above the plate 41, the ultraviolet light with high energy contained in the plasma radiation light is blocked by the upper shower plate 40, so that the effect of suppressing damage to the substrate to be processed 100 can be enhanced.

  If the plasma is set to be generated below the plate 41, the first gas can be distributed and supplied to the plasma through the upper shower plate 40, so that the uniformity of the plasma can be improved. When the plasma is set to be generated below the plate 41, the electromagnetic wave incident surface F is an interface (the lower surface of the plate 41) between the plate 41 and the internal space of the vacuum vessel 2, and in other cases, the electromagnetic wave. The incident surface F is an interface between the dielectric window 3 and the internal space of the vacuum vessel 2 (inner surface of the dielectric window 3).

  The lower gas introduction system 7 has a lower shower plate 50 as a second gas introduction part (lower gas introduction part). The lower shower plate 50 is formed to a size that covers the substrate 100 to be processed supported by the substrate support 4. The lower shower plate 50 has a pair of plate members 51a and 51b facing each other and is formed in a flat box shape, and the second gas is circulated in the internal space S3. The internal space S3 of the lower shower plate 50 is open to the outside of the vacuum vessel 2 through an opening 52 formed in the peripheral wall 2c of the vacuum vessel 2. From the opening 52, the second gas is introduced into the internal space S3 of the lower shower plate 50.

  In addition, a large number of gas jets 53 are provided in the lower plate member 51 b of the lower shower plate 50. In the lower shower plate 50, the opening ratio per unit area of the plurality of gas jets 53 is set on the upstream side of the gas flow in the lower shower plate 50, and the conductance (physical resistance of the gas jets 53 with respect to this gas flow). The reciprocal number is small, and the conductance of the gas outlet 53 for the gas flow is set to be large on the downstream side of the gas flow in the lower shower plate 50. Specifically, the opening ratio per unit area of the plurality of gas ejection ports 53 is set so that the upstream side of the gas flow in the lower shower plate 50 is small and the downstream side of the gas flow is large. In this way, the second gas can be uniformly discharged into the vacuum container 2 from a region corresponding to substantially the entire lower surface of the lower shower plate 50. Although not shown, the lower shower plate 50 has a plurality of through holes for allowing the first gas and oxygen radicals to flow between the upper region of the lower shower plate 50 and the lower region of the lower shower plate 50. have.

  It is desirable to keep the lower gas introduction system 7 at a temperature of about 80 ° C. to 200 ° C. Therefore, the lower gas introduction system 7 may be provided with the heating means 11 provided in the insulating film forming apparatus 1 of the first embodiment, the heating means 11 provided in the insulating film forming apparatus 1 of the second embodiment, and the like. .

  As described above, if the insulating film forming apparatus 1 according to the present embodiment is used, the second gas can be uniformly supplied into the vacuum container 2 from above the substrate to be processed 100, so that the substrate 100 is insulated. In forming the film 101, good film thickness controllability and film thickness uniformity can be realized.

  Hereinafter, a fourth embodiment of the present invention will be described with reference to FIG. In the present embodiment, an embodiment of the insulating film forming apparatus of the present invention will be described.

  The insulating film forming apparatus of the present embodiment is different from the insulating film forming apparatus 1 described in the first embodiment in the upper gas introducing system 6 and the lower gas introducing system 7, but the other configuration is the above-described first structure. Since this is the same as the insulating film forming apparatus 1 of the embodiment, overlapping description is given with the same reference numerals in the drawings and omitted.

  The upper gas introduction system 6 is the same as the upper gas introduction system 6 provided in the insulating film forming apparatus 1 described in the third embodiment.

  The lower gas introduction system 7 has a lower shower plate 60 as a lower gas introduction part. The lower shower plate 60 is formed to a size that covers the substrate to be processed 100 supported by the substrate support 4. The lower shower plate 60 has a pair of plate members 61a and 61b facing each other and is formed in a flat box shape so that the second gas is circulated in the internal space S4. The internal space S4 of the lower shower plate 60 is open to the outside of the vacuum vessel 2 through an opening 62 formed in the peripheral wall 2c of the vacuum vessel 2. From the opening 62, the second gas is introduced into the internal space S4 of the lower shower plate 60.

  In the internal space S4 of the lower shower plate 60, a plurality of partition walls 64 for adjusting the flow of the second gas are provided. These partition walls 64 have a large conductance of the partition wall 64 with respect to the gas flow on the upstream side of the gas flow in the lower shower plate 60, and a conductance of the partition wall 64 with respect to the gas flow on the downstream side of the gas flow in the lower shower plate 60. The size is set to be smaller. Specifically, the height of each partition wall 64 is set so that it is lower on the upstream side of the gas flow in the lower shower plate 60 and higher on the downstream side of the gas flow. Thus, by reducing the upstream partition wall 64 of the gas flow having a high second gas inflow pressure, it is possible to increase the conductance on the upstream side of the gas flow and to increase the inflow pressure of the second gas. By increasing the partition wall 64 on the downstream side of the low gas flow, the conductance on the downstream side of the gas flow can be reduced.

  A large number of gas outlets 63 are provided in the lower plate member 61 a on the lower side of the lower shower plate 60 so as to correspond to the respective regions divided by the partition walls 64. By doing so, the second gas is divided into a flow passing through the gap 65 restricted by the partition wall 64 and a flow ejected from the gas ejection port 63. By changing the conductance by the partition wall 64, the flow rate ratio between the flow through the gap 65 and the flow ejected from the gas ejection port 63 can be adjusted. By adjusting this flow rate ratio to a desired value, the second gas can be uniformly discharged into the vacuum container 2 from a region corresponding to substantially the entire lower surface of the lower shower plate 60. Although not shown, the lower shower plate 60 has a plurality of through holes for allowing the first gas and oxygen radicals to flow between the upper region of the lower shower plate 60 and the lower region of the lower shower plate 60. have.

  It is desirable to keep the lower gas introduction system 7 at a temperature of about 80 ° C. to 200 ° C. Therefore, the lower gas introduction system 7 may be provided with the heating means 11 provided in the insulating film forming apparatus 1 of the first embodiment, the heating means 11 provided in the insulating film forming apparatus 1 of the second embodiment, and the like. .

  As described above, if the insulating film forming apparatus 1 according to the present embodiment is used, the second gas can be uniformly supplied into the vacuum container 2 from above the substrate to be processed 100, so that the substrate 100 is insulated. In forming the film 101, good film thickness controllability and film thickness uniformity can be realized.

  Hereinafter, a fifth embodiment of the present invention will be described with reference to FIG. In the present embodiment, an embodiment of the insulating film forming apparatus of the present invention will be described.

  The insulating film forming apparatus 1 of the present embodiment is different from the insulating film forming apparatus 1 described in the first embodiment in the upper gas introduction system 6 and the lower gas introduction system 7, but the other configurations are the same as those described above. Since it is the same as that of the insulating film forming apparatus 1 of the first embodiment, the overlapping description is omitted by attaching the same reference numerals to the drawings.

  The upper gas introduction system 6 is the same as the upper gas introduction system 6 provided in the insulating film forming apparatus 1 described in the third embodiment.

  The lower gas introduction system 7 has a lower shower plate 70 as a second gas introduction part (lower gas introduction part). The lower shower plate 70 is formed to a size that covers the substrate 100 to be processed supported by the substrate support 4. The lower shower plate 70 has a pair of plate members 71a and 71b facing each other and is formed in a flat box shape. A diffusion plate 74 having a plurality of openings 74a is provided between the pair of plate members 71a and 71c. By this diffusion plate 74, the internal space S5 of the lower shower plate 70 is divided into an upper gas chamber G1 as a first gas chamber and a lower gas chamber G2 as a second gas chamber. The upper gas chamber G1 in the internal space S5 of the lower shower plate 70 is open to the outside of the vacuum vessel 2 through an opening 72 formed in the peripheral wall 2c of the vacuum vessel 2. From this opening 62, the second gas is introduced into the upper gas chamber G1 of the lower shower plate. Further, the lower plate member 71 b of the lower shower plate 70 has a plurality of gas ejection ports 73.

  In the lower shower plate 70, the gas flow is adjusted between the upper gas chamber G1 and the lower gas chamber G2 according to the size, number, shape, etc. of the opening 74a of the diffusion plate 74. . In the present embodiment, the opening ratio per unit area of the opening 74 a of the diffusion plate 74 is such that the conductance of the opening 74 a with respect to the gas flow is small on the upstream side of the gas flow in the lower shower plate 70, and the lower shower plate 70. The conductance of the opening 74a with respect to the gas flow is set so as to increase on the downstream side of the gas flow. Specifically, on the upstream side of the gas flow having a high inflow pressure of the second gas, the conductance is reduced by reducing the opening area per unit area of the diffusion plate 74, and the inflow pressure of the second gas is low. On the downstream side of the gas flow, the conductance is increased by increasing the opening area. By doing so, the second gas can be uniformly sent toward the lower gas chamber G2 from the region corresponding to substantially the entire lower surface of the diffusion plate 74. As a result, the lower shower plate 57 The second gas is uniformly discharged toward the inside of the vacuum container 2 from a region corresponding to substantially the entire lower surface.

  It is desirable to keep the lower gas introduction system 7 at a temperature of about 80 ° C. to 200 ° C. Therefore, the lower gas introduction system 7 may be provided with the heating means 11 provided in the insulating film forming apparatus 1 of the first embodiment, the heating means 11 provided in the insulating film forming apparatus 1 of the second embodiment, and the like. .

  As described above, if the insulating film forming apparatus 1 according to the present embodiment is used, the second gas can be uniformly supplied into the vacuum container 2 from above the substrate to be processed 100, so that the substrate 100 is insulated. In forming the film 101, good film thickness controllability and film thickness uniformity can be realized.

  Hereinafter, a sixth embodiment of the present invention will be described with reference to FIG. In the present embodiment, an embodiment of the insulating film forming apparatus of the present invention will be described.

  The insulating film forming apparatus 1 of the present embodiment is different from the insulating film forming apparatus 1 described in the first embodiment in the upper gas introduction system 6, but the other configuration is the insulation of the first embodiment described above. Since it is the same as the film forming apparatus 1, overlapping description is omitted by attaching the same reference numerals to the drawings.

  The upper gas introduction system 6 of this embodiment is formed integrally with the dielectric window 3. Specifically, the dielectric window 3 has a gas flow path 81 through which the first gas flows, a plurality of communication paths 82 that connect the gas flow path 81 and the inside of the vacuum vessel 2, and a gas flow path. 81 and a communication pipe 83 that communicates the outside of the vacuum vessel 2. The gas flow path 81 and the plurality of communication paths 82 are formed by cutting the dielectric window 3 or the like. Each communication pipe 83 communicates with the gas flow path 81. The gas flow path 81 and the communication pipe 83 constitute a first gas introduction part (upper gas introduction part), and the open end of the communication path 82 introduces the first gas into the vacuum vessel 2. It becomes a spout.

  The communication pipe 83 is piped into a through hole 84 formed in the upper wall 2 a of the vacuum vessel 2 and extends outward from the vacuum vessel 2. The communication pipe 83 may be integral with or separate from the dielectric window 3. Also in this case, the inner surface of the dielectric window 3 becomes the electromagnetic wave incident surface F. Since the other configuration is the same as that of the insulating film forming apparatus 1 of the first embodiment, the overlapping description will be omitted by attaching the same reference numerals to the drawings.

  According to the insulating film forming apparatus 1 of this embodiment, the first gas supplied from the first gas introduction system can be efficiently decomposed in the vicinity of the dielectric member 3, and oxygen radicals can be generated efficiently.

  The insulating film forming method and the insulating film forming apparatus of the present invention are not limited to the above-described embodiments, and can be implemented in various ways without departing from the gist thereof.

Sectional drawing which shows the insulating film forming apparatus of the 1st reference example for enforcing the method which concerns on the 1st Embodiment of this invention. Sectional drawing shown along the II-II line | wire in FIG. Sectional drawing shown along the III-III line | wire in FIG. Sectional drawing which shows the insulating film forming apparatus which concerns on a 2nd reference example . Sectional drawing shown along the VV line in FIG. Sectional drawing which shows the insulating film forming apparatus which concerns on a 3rd reference example . Sectional drawing which shows the insulating film forming apparatus which concerns on the 4th reference example . Sectional drawing which shows the insulating film forming apparatus which concerns on a 5th reference example . Sectional drawing which shows the insulating film forming apparatus which concerns on a 6th reference example . The figure which shows the relationship between the distance from an electromagnetic wave incident surface, and electron temperature. The figure which shows the relationship between the distance from an electromagnetic wave incident surface, and an electron density.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 1a, 1b, 1c, 1d, 1e, 1f ... Insulating film formation apparatus, 2 ... Vacuum container (processing container), 3 ... Dielectric window (dielectric member), 6 ... Upper gas introduction system (1st gas introduction system) ), 7 ... Lower gas introduction system (second gas introduction system), 8 ... High frequency power supply, 10 ... Waveguide slot antenna, 11 heating means, 100 ... Substrate 100, 101 ... Insulating film, F ... Incident electromagnetic wave surface,

Claims (3)

A step of disposing a substrate to be processed inside a processing container having an electromagnetic wave incident surface on which electromagnetic waves are incident;
Introducing a first gas containing at least one of a rare gas and an oxygen gas into the vacuum processing vessel from a position where the distance from the electromagnetic wave incident surface is less than 10 mm;
A second gas containing an organosilicon compound is separated from the first gas from an annular lower gas introduction pipe which is provided at a position where the distance from the electromagnetic wave incident surface is 10 mm or more and is larger than the substrate to be processed. Introducing into the processing vessel;
By causing electromagnetic waves to enter the inside of the processing container from the electromagnetic wave incident surface, surface wave plasma is generated by the first gas in the vicinity of the electromagnetic wave incident surface inside the processing container, and radicals of the first gas are generated. A step of generating,
Without providing a shower head between the introduction position of the first gas and the introduction position of the second gas, the radical reaches the atmosphere of the second gas as a diffusion flow in a vacuum, and the second gas Depositing silicon oxide on the substrate to be processed by reacting with the gas of
An insulating film forming method, wherein an insulating film having a stable film thickness is formed by directly heating the lower gas introduction pipe to 80 ° C. to 200 ° C. 2. The method for forming an insulating film according to claim 1, wherein the first gas contains at least one rare gas of helium, neon, argon, krypton, and xenon. The first gas contains oxygen gas, and the flow rate of oxygen gas when supplying the oxygen gas into the processing container is such that the second gas is introduced into the processing container. The method for forming an insulating film according to claim 1, wherein the insulating film is set to have a flow rate greater than that of the second gas .

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