JP2001234338A - Deposition method of metallic compound thin film and deposition system therefor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a deposition method of a metallic compound thin film for depositing the metallic compound thin film free from metallic imperfect reactants at a high speed and to provide a deposition system therefor. SOLUTION: The method comprizes a stage in which a.c. voltage is applied in such a manner that, as to plural sputtering targets 29a, 29b, 49a and 49b, each target 29a, 29b, 49a and 49b is alternatively made into a cathode and an anode, and simultaneously, any target is made into a cathode, and any target is made into an anode at all times, inert gas and reactive gas are introduced, and a metallic imperfect reactant superthin film is deposited on a substrate at film deposition process zones 20 and 40 in a vacuum tank 11, a stage in which the metallic imperfect reactant superthin film is converted into a metallic compound superthin film with the active seed of electrically neutral reactive gas at a reaction process zone 60 in the vacuum tank 11 and a stage in which these two stages are repeatedly performed in succession.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a method for forming a metal compound thin film and an apparatus for forming the same, and more particularly to a method for forming a metal compound thin film stably and at high speed on a substrate by a sputtering method and an apparatus for forming the same. .

[0002]

2. Description of the Related Art Sputtering is widely used to form thin films of metal compounds such as oxides, nitrides, and fluorides. There are the following representative methods for forming thin films of these metal compounds. 1. A reactive gas (eg, oxygen, nitrogen, or fluorine gas) is introduced into a metal compound target (insulating) or a metal target (conductive) using a high-frequency (RF) power supply, and a thin film is formed by reactive sputtering. Method (hereinafter referred to as RF reactive sputtering method). 2. A method of forming a thin film by reactive sputtering by introducing a reactive gas (for example, oxygen, nitrogen, or fluorine gas) to a metal target (conductive) using a direct current (DC) power supply (hereinafter, DC reactive sputtering method) ). These methods are the most commonly used methods for forming a metal compound thin film.

However, these methods have a problem that the deposition rate of a thin film is low as shown in FIG. Here, FIG. 10 is a diagram showing a relationship between a film formation rate (a thin film formation rate) and a ratio of a reactive gas flow rate / a total gas flow rate. The reactive gas flow rate and the total gas flow rate refer to the respective gas flow rates near the target. The RF / DC reactive sputtering method in which a reactive gas is introduced into a region where a target is placed corresponds to the region D in the graph, and the film formation rate is lower than when the flow ratio of the reactive gas is small. I understand. For example, the deposition rate of the metal compound thin film by the RF, DC reactive sputtering method is one time smaller than the deposition rate of the metal thin film by sputtering.
/ 5 to 1/10. Further, the deposition rate of the metal compound thin film by the RF or DC reactive sputtering method is about 1/2 to 1/10 as compared with the vacuum deposition by the ion beam heating method or the resistance heating method. Therefore, the RF and DC reactive sputtering method has a problem in mass production.

Therefore, in order to increase the film forming rate, R
In the F, DC reactive sputtering method, the amount of a reactive gas (eg, oxygen, nitrogen, or fluorine gas) to be introduced can be reduced. However, when the amount of the reactive gas (for example, oxygen, nitrogen, or fluorine gas) to be introduced is reduced, there is a problem that an incomplete metal compound thin film deficient in the constituent elements of oxygen, nitrogen, and fluorine tends to be formed.

For example, in order to form a SiO ₂ thin film which is a typical oxide thin film used for an optical film, an insulating film, a protective film, etc., a high frequency power supply is used by using an SiO ₂ target (insulating). It is common practice to perform RF reactive magnetron sputtering by using a silicon (Si) target (conductive), introduce a oxygen gas using a DC power source, and perform DC reactive magnetron sputtering. is there. At this time, if the oxygen gas, which is a reactive gas introduced at the same time as the operating gas for sputtering (for example, argon gas), is insufficient, the composition of the formed thin film becomes SiO _x (x <2).

Further, the RF and DC reactive sputtering method has a problem that an arc discharge (abnormal discharge) is easily generated. This arc discharge causes the following problems. 1. The target material scatters on the substrate, causing defects in the thin film being formed. 2. An arc mark remains on the target surface, and the accumulation of SiO ₂ , which is an insulating portion, progresses around the arc mark, and further abnormal discharge occurs.

Here, the mechanism of occurrence of arc discharge (abnormal discharge) in the target is as follows.
That is, in the RF and DC reactive sputtering method, the reactive gas introduced into the region where the target is arranged reacts on the surface of the target to form SiO ₂ . In this SiO ₂ , charges of plasma argon ions and oxygen ions are accumulated. This positively charged charge accumulates in large quantities on the target surface. This charge is
When the insulation limit of the SiO ₂ film is exceeded, dielectric breakdown occurs. And this charge is the conductive part of the target,
An arc discharge is caused to the earth shield (anode). When an arc occurs, the accumulated charge escapes from the target surface.

In RF and DC reactive sputtering, since a film is usually formed by using plasma, components of the apparatus, a substrate holder, a substrate, and the like are collided by charged particles (ions, electrons). Heated. Therefore,
There is also a problem that it is difficult to perform sputtering at 100 ° C. or less, and it is difficult to form a film on a material having low heat resistance such as plastic. This problem is particularly remarkable in RF magnetron sputtering using a high-frequency power supply, and development of a method capable of performing sputtering at a low temperature is desired.

Therefore, in order to solve the above-mentioned problems, in recent years, a metal mode (for example, Meta Mo
de), a new method of forming a metal compound thin film by sputtering called twin magnetron sputtering has been developed. The drum-rotating metal mode (for example, Meta Mode) means that a film forming chamber provided with a target and a plasma generating unit, a reactive gas introducing unit, and a target are provided outside a cylindrical substrate holder provided in a vacuum vessel. By using a device provided with a reaction chamber provided with a plasma generating means and separated, the substrate holder is rotated to deposit an ultra-thin metal film on the substrate by sputtering in the film formation chamber, and reacting gas in the reaction chamber. And the conversion of a metal ultra-thin film into a metal compound by plasma generated by introducing the compound. In this method, unlike RF and DC reactive sputtering, no reactive gas is introduced into the deposition chamber in which the target is placed, so that arc discharge does not easily occur and the metal compound thin film can be deposited at a high speed. It is. That is, when sputtering is performed in the metal mode of the drum rotation type (for example, Meta Mode), the film forming rate (the thin film forming rate)
The relationship between the ratio and the ratio of the reactive gas flow rate / total gas flow rate corresponds to point A (reactive gas flow rate / total gas flow rate ratio = 0%) in FIG. It is possible to form an oxide thin film or the like at a high speed as compared with the DC reactive sputtering method (region D).

[0010] Twin magnetron sputtering is a type of dual magnetron sputtering. Here, the dual magnetron sputtering means that one target is always cathode (negative) by alternately applying positive and negative alternating voltages to a pair of same or different targets electrically insulated from the ground potential. And magnetron sputtering while introducing a reactive gas so that the other target always becomes the anode (positive pole).

In this dual magnetron sputtering, one of a pair of sputtering targets is used as a cathode and the other is used as an anode, and the two targets are alternately changed to an anode and a cathode by an alternating electric field. When the anode is converted to the cathode by the electric field, the incomplete reactant metal attached to the target surface at the time of the anode is sputtered and returns to the original normal state. Therefore, a stable anode potential state is always obtained, a change in plasma potential (generally, substantially equal to the anode potential) can be prevented, and high-speed deposition of an oxide thin film or the like and occurrence of arc discharge can be prevented.
That is, in the conventional RF, DC reactive magnetron sputtering method, the phenomenon that the target potential, the device component, and the device body serving as the anode are covered with the non-conductive or low-conductive incomplete metal and the anode potential is reduced is prevented. You can.

[0012] Twin magnetron sputtering,
As described above, this is a kind of the dual magnetron sputtering. This twin magnetron sputtering uses an insulator for the non-erosion part of the target, applies an AC voltage to the sputter electrode from a power supply for sputtering, and applies an AC voltage at a frequency much higher than the sputter voltage from an oscillation circuit. This is characterized in that the sputtering voltage is feedback-controlled based on the ratio of the reactive gas flow rate / total gas flow rate near the target, and the film forming rate is controlled by this voltage. Arcing is reduced by using an insulator for the non-eroded portion of the target. The oscillating circuit oscillates when an arc is about to occur due to accumulation of electric charge, and generates an additional polarity alternation of the cathode to extinguish the arc.

In the feedback control, there is a correlation between the sputtering voltage and the film forming speed. Therefore, the film forming speed can be controlled by using the voltage as a parameter for controlling the film forming speed. . Then, between the voltage serving as this parameter and the reactive gas flow rate / total gas flow rate ratio, there is almost the same relationship as the relationship between the deposition rate and the reactive gas flow rate / total gas flow rate ratio in FIG. The value of the voltage can be feedback-controlled by the flow rate of the reactive gas. Therefore, in this twin magnetron sputtering, the film forming rate is adjusted to a desired value by adjusting the flow rate of the reactive gas and using the value of the voltage as a parameter.

The twin magnetron sputtering is a method for compensating for the problems of the metal compound thin film forming method using the metal mode and the compound mode. That is,
According to this method, the compound thin film can be directly deposited on the substrate in the transition region between the metal mode and the compound mode (region C in FIG. 10), and the abnormal discharge is reduced. Compared with the RF reactive sputtering method and the DC reactive sputtering method (region D), which have been most often used in the past, high-speed and stable film formation can be performed. Regarding twin magnetron sputtering, see, for example, Japanese Patent Application Laid-Open No. 4-325680.
Patent Publication, Japanese Patent Laid-Open Publication No. Hei 5-222531, Japanese Patent Publication No. 257
No. 4636, and the like.

However, in the above-described drum-rotating metal mode (for example, Meta Mode) or twin magnetron sputtering, a strong stress is generated in the formed metal compound thin film, and it is difficult to reduce the optical absorption of the thin film. There is a problem. In conventional twin magnetron sputtering, a reactive gas is introduced into a vacuum vessel in which a pair of targets are arranged when forming a metal compound film. However, according to this method, an abnormal discharge is prevented. However, since a sufficient amount of reactive gas cannot be introduced into the vicinity of the target, oxygen as a reactive gas becomes insufficient, and the composition of the thin film becomes an incomplete reactant such as SiO _x (x <2). is there.

[0016]

SUMMARY OF THE INVENTION The present invention has been made to solve each of the problems of the above-mentioned conventional sputtering film forming methods. An object of the present invention is to provide a metal compound thin film forming method and a forming apparatus capable of forming a metal compound thin film having characteristics at high speed. Another object of the present invention is to provide a method and an apparatus for forming a metal compound thin film capable of forming a high-quality metal compound thin film with less optical absorption and less optical stress at a high speed. is there.

[0017]

According to the first aspect of the present invention, a plurality of sputtering targets which are electrically insulated from a ground potential are provided at the same time as each target alternates between a cathode and an anode. An AC voltage is applied so that an inert gas and a reactive gas are introduced so that one of the targets becomes a cathode and one of the targets becomes an anode. Forming a metal imperfect reactant ultra-thin film composed of the imperfect reactant of the above, and the reaction process zone spatially and pressure-separated from the film forming process zone in the vacuum chamber. Contacting the ultra-thin product with an active species of an electrically neutral reactive gas, and reacting the ultra-thin metal incomplete reactant with the active species of the reactive gas to form a metal compound A step of sequentially converting the step of converting to a thin film, the step of forming the ultra-thin metal reactant ultra-thin film, and the step of converting to the ultra-thin metal compound thin film, to form a plurality of ultra-thin metal compound layers The problem is solved by depositing and forming the metal compound thin film having a desired thickness on a substrate.

As described above, since a reaction mechanism for sequentially forming an ultra-thin metal reactant thin film and then converting the ultra-thin metal compound into an ultra-thin metal compound film is employed, a thin film having smaller stress can be formed, and It is possible to form a high-quality metal compound thin film with little absorption at a high speed.

In the step of forming an ultrathin metal reactant thin film, an AC voltage is applied so that each target alternates between a cathode and an anode, and at the same time, one of the targets is always a cathode and one of the targets is an anode. Is applied, the non-conductive or low-conductive metal compound attached to the target surface when each target is an anode is removed from the target surface when the target becomes a cathode. Therefore, the accumulation of the metal compound on the surface of each target is prevented, a stable anode portion is secured, the change in anode potential is prevented, and a high-quality thin film with good reproducibility can be formed.

In this case, the active species of the electrically neutral reactive gas includes at least one of a radical, an excited radical, an excited atom, and an excited molecule. This is preferable. These radicals, radicals in an excited state, atoms in an excited state, and molecules in an excited state are charged with ions, electrons, and the like in a chemical reaction in a reactive film forming process of obtaining a metal compound from an incomplete metal reactant. It plays a more important role than particles. In addition, it has the property of not damaging a thin film unlike charged particles. Therefore, in the present invention, the active species of an electrically neutral reactive gas containing at least one of a radical having the above characteristics, a radical in an excited state, an atom in an excited state, and a molecule in an excited state Since it is used, it is possible to perform a step of efficiently converting it to a metal compound ultrathin film.

Further, the active species of the electrically neutral reactive gas is a grid for introducing a reactive gas to generate a reactive gas plasma and selectively passing the electrically neutral active species. It is preferable to introduce the gas into the vacuum chamber through the vacuum chamber.

According to a fourth aspect of the present invention, there is provided an apparatus for forming a metal compound thin film on a substrate by sputtering, wherein a gas introducing means for introducing a reactive gas and an inert gas, and an electric power supply from a ground potential. A plurality of sputtering targets that are electrically insulated and connected to an AC power source and can be alternately applied to a positive potential and a negative potential by the AC power source are provided, and the metal incomplete reactant ultrathin film is formed on the substrate. A film forming process zone formed in a vacuum chamber for performing a forming step, and a means for generating an electrically neutral reactive gas active species, wherein the metal incomplete reactant ultrathin film and the activity of the reactive gas are provided. A reaction process zone formed in a vacuum chamber for performing a step of reacting with a seed to convert it into a metal compound ultra-thin film, between the film formation process zone and the reaction process zone A substrate holder for carrying the serial board, spatial and said reaction process zone and the deposition process zone, is solved by providing a shielding means for the pressure separated.

As described above, since the film forming process zone and the reaction process zone are separated by the shielding means,
An ultra-thin metal incomplete reactant film is formed in the film formation process zone, and it can be converted into an ultra-thin metal compound compound in the reaction process zone. A reaction mechanism for sequentially converting a compound ultrathin film can be employed, a thin film having smaller stress can be formed, and a high-quality metal compound thin film having little optical absorption can be formed at a high speed. Further, since the film forming process zone and the reaction process zone are separated by the shielding means, the film forming process zone and the reaction process zone are not completely separated from each other, but are separated in a substantially independent vacuum atmosphere. Space.

As a result, each zone can have a vacuum atmosphere in which the influence from other zones is individually suppressed, and optimum conditions can be set for each zone. For example, discharge by sputtering and discharge by generation of active species of reactive gas can be controlled separately and do not affect each other, so that stable discharge can be achieved and reliability can be improved without causing accidents. Can be increased. Further, the flow rate of the reactive gas in the film forming process zone can be easily controlled, and abnormal discharge can be prevented.
Furthermore, since the shielding means is provided, it is possible to prevent the deposition material from being mixed into another film formation process zone, particularly when a different type of target is used for each film formation process zone. At this time, it is preferable that the film forming process zone and the reaction process zone are formed in the same vacuum chamber.

The active species generating means includes a reactive gas introducing means for introducing a reactive gas, and a reactive gas plasma generating means connected to a power supply for applying a voltage.
Preferably, a grid is provided for selectively passing the electrically neutral active species in the reactive gas plasma generated by the reactive gas plasma generating means. As described above, the reactive gas plasma generating means and the grid for selectively passing the electrically neutral active species in the reactive gas plasma generated by the reactive gas plasma generating means are provided. In the reaction of converting incomplete metal reactants to metal compounds, radicals that play a more important role than charged particles such as ions and electrons, radicals in excited state, atoms in excited state, and excited state A certain molecule can be used, and a step of efficiently converting it to a metal compound ultrathin film can be performed.

Further, it is preferable that the substrate holder is electrically insulated from the vacuum chamber. This allows
It is possible to prevent abnormal discharge in the substrate.

Further, the film forming process zone and the reaction process zone are formed in the same vacuum chamber, and a substrate loading chamber for mounting the substrate on the substrate holder;
A substrate unloading chamber for detaching the substrate from the substrate holder, wherein the substrate loading chamber and the vacuum chamber, and the substrate unloading chamber and the vacuum chamber each have a pressure-separable shutoff means. The substrate loading chamber, the vacuum chamber, and the substrate unloading chamber each have their own evacuation means, and between the substrate loading chamber, the vacuum chamber, and the substrate unloading chamber, It is preferable that a substrate holder conveying means for conveying the substrate holder is provided.

[0028]

BEST MODE FOR CARRYING OUT THE INVENTION The present invention provides a method for forming a plurality of ultrathin metal compound thin films by sputtering and depositing them.
The present invention relates to a method of forming a metal compound thin film having a target thickness on a substrate.

The term “ultra-thin film” used in the present invention is a term used to prevent confusion with the final thin film because the ultra-thin film is deposited a plurality of times to form a final thin film. It means that it is much thinner than a thin film. The average thickness of the ultrathin film is arbitrary, but is preferably about 0.1 to 15 Å. The present invention provides a bipolar sputter,
3-pole sputtering, 4-pole sputtering, magnetron sputtering,
It can be performed by various known sputtering methods such as ECR sputtering and bias sputtering.

According to the present invention, a plurality of sputtering targets 29a, 29b, 49a, 49b of the same type or different types, which are electrically insulated from the vacuum chamber 11 at the ground potential, are provided with a cathode and a target, respectively. At the same time as alternating with the anode, any one of the targets 29a, 29b, 49a, 49b becomes a cathode and any one of the targets 49a, 49b, 29a, 2
1KHz or more and 100KH so that 9b becomes the anode
An AC voltage of z or less is applied, and an inert gas and a reactive gas, which are operating gases, are introduced. In the film forming process zones 20 and 40 in the vacuum chamber 11, a metal is formed on the substrate by an incomplete reactant. Forming an ultra-thin metal reactant thin film; and forming a reaction process zone 60 spatially and pressure-separated from the film formation process zones 20 and 40 in the vacuum chamber 11.
Then, the ultra-thin metal incomplete reactant ultra-thin film is brought into contact with an active species of an electrically neutral reactive gas, and the ultra-thin metal incomplete reactant is reacted with the active species of the reactive gas to form a metal compound. Forming a plurality of ultra-thin metal compound thin films by sequentially repeating the steps of converting to an ultra-thin film, forming the ultra-thin metal reactant ultra-thin film, and converting to ultra-thin metal compound film. Then, a metal compound thin film is formed.

In the present invention, the step of forming an ultrathin metal reactant thin film and the step of converting it into an ultrathin metal compound may be sequentially repeated, and these steps are repeated by rotating a drum type substrate holder. In addition to the method for performing the process, a plurality of film forming process zones 20 and 40 are provided, and targets 29a and 29
By using targets having different compositions as b, 49a, and 49b, a composite metal compound thin film can be formed.

The pressure in the film forming process zones 20 and 40 is
It is preferable that the pressure be 1.0 × 10 ^{−1 to} 1.3 Pa. The flow ratio of the reactive gas introduced into the film forming process zones 20 and 40 is slightly different depending on the type of the reactive gas to be introduced, but is about 20% or less of the total gas flow in the film forming process zones 20 and 40, preferably. It is good to be about 8% or less. By setting this ratio, the film forming process zones 20, 4
It is possible to prevent abnormal discharge from occurring on the target surface of zero. In addition, the film forming process zones 20 and 4
The flow rate ratio of the reactive gas introduced to 0 is slightly different depending on the type of the reactive gas to be introduced, but it is assumed that it is about 3% or more, preferably about 5% or more of the total gas flow rate in the film forming process zones 20 and 40. Good. With this ratio, it is possible to form a high-quality metal compound thin film with little optical absorption at a high speed with a small stress.

The process of forming a composite metal compound thin film on a substrate will be described with reference to FIG. 11, taking the case of forming a composite metal oxide thin film as an example. First, the substrate
It is placed in the film forming process zone 20 so as to face the first metal targets 29a and 29b. Then, while introducing oxygen gas as a reactive gas, the first metal targets 29a and 29b are sputtered to form a very thin first metal incomplete oxide ultrathin film (FIG. 11).
left).

Next, the substrate is placed on the second metal target 49.
a, 49b so as to face the film forming process zone 40.
Place. At this position, the second metal targets 49a and 49b are sputtered while introducing oxygen gas as a reactive gas to form a very thin second metal incomplete oxide ultrathin film (FIG. 11 center). . At this time, the first ultra-thin metal incomplete oxide film and the second ultra-thin metal incomplete oxide thin film are uniformly formed on the substrate. That is, an ultrathin film made of an incomplete oxide of a composite metal is formed on the substrate.

The ultra-thin film formed on the substrate is irradiated with an active species of oxygen gas as an electrically neutral reactive gas, and the ultra-thin film is reacted with the active species of oxygen gas to form a composite. It is converted to a metal oxide (Fig. 11, right). In particular,
Oxidation occurs in the reaction process zone 60 where the radical source exists.
The step of forming the ultrathin film and the step of converting the compound into a compound of a composite metal are sequentially repeated to form a composite metal compound thin film having a desired thickness on the substrate. In the present embodiment,
The step of forming an ultra-thin film and the step of converting it to a compound of a composite metal are sequentially repeated to form a compound metal compound thin film of a desired thickness on the substrate, the substrate may be transported, or the substrate may be fixed. Is also good.

In the step of converting into a metal compound ultrathin film,
Radicals, as active species of electrically neutral reactive gases,
A substance containing at least one of a radical in an excited state, an atom in an excited state, and a molecule in an excited state is used. The active species of this electrically neutral reactive gas generate reactive gas plasma by introducing the reactive gas, selectively trap electrons and ions as charged particles, The active species are generated by passing through a grid 81 for selectively passing them. Through this grid 81, active species of an electrically neutral reactive gas are supplied to the vacuum chamber 11.
Introduce within.

The present invention also relates to an apparatus for forming a metal compound thin film by sputtering. The apparatus according to the present invention includes gas introduction means 25 and 45 for introducing a reactive gas and an inert gas, and film formation process zones 20 and 4.
0, a reaction process zone 60, a substrate holder 13 for transferring a substrate between the film formation process zones 20 and 40, and the reaction process zone 60;
It comprises shielding means 12, 14, 16 for spatially and pressure-separating 40 from the reaction process zone 60.

The film forming process zones 20 and 40 are formed in the vacuum chamber 11. Film forming process zones 20, 4
At 0, there are provided a plurality of sputtering targets which are electrically insulated from the ground potential and which are connected to an AC power supply and which can alternately apply a positive potential and a negative potential by the AC power supply. In this zone, a step of forming an ultrathin metal incomplete reactant film on the substrate is performed. The reaction process zone 60 is formed in the vacuum chamber 11 and includes means 61 for generating an electrically neutral reactive gas active species. In this zone 60, a step of reacting the ultra-thin metal incomplete reactant film with the active species of the reactive gas to convert it into a ultra-thin metal compound film is performed.

At this time, in particular, the film forming process zone 20,
The pressure at 40 is higher than the reaction process zone 60.
This prevents the reactive gas introduced into the reaction process zone 60 from flowing into the film formation process zones 20 and 40, and reduces the flow rate of the reactive gas in the film formation process zones 20 and 40 to a predetermined flow rate. It can be maintained. In this example, the film forming process zones 20 and 40 and the reaction process zone 60 are formed in the same vacuum chamber 11.

The means 61 for generating an electrically neutral reactive gas active species generates at least one of a radical, an excited radical, an excited atom, and an excited molecule. Device. The active species generating means 61 includes a reactive gas introducing means 77 for introducing a reactive gas, and applies a voltage of 1 KHz to 100 KH for applying a voltage.
a reactive gas plasma generating means 63 connected to an AC power supply 69 of z or less, and selectively allowing electrically neutral active species in the reactive gas plasma generated by the reactive gas plasma generating means 63 to pass therethrough. And a grid 81.

The plasma generated by the discharge in the reactive gas plasma generation chamber 63 of the active species generator 61 includes plasma ions, electrons, radicals, radicals in excited state, atoms, molecules and the like. In the present invention, the grid 81 is configured so that radicals, active radicals, atoms, molecules, and the like in the reactive gas plasma are selectively or preferentially guided to the reaction process zone 60 in the reactive gas plasma. Then, electrons and ions as charged particles are prevented from passing through the grid 81 and do not leak to the reaction process zone 60.

Accordingly, in the reaction process zone 60, the ultra-thin metal reactant ultra-thin film is exposed to an active species of an electrically neutral reactive gas and reacted without being exposed to charged particles. Incomplete oxide thin films are converted into metal compounds. Here, the radical is a radical and is an atom or a molecule having one or more unpaired electrons. In addition, the excited state (exc
The “item state” refers to a state having higher energy than a stable ground state having the lowest energy. As the grid 81, a multi-aperture grid 101 or a multi-slit grid 111 is used.

As the reactive gas plasma generating chamber 63 of the active species generating means 61, a coil-shaped electrode is arranged on the atmosphere-side peripheral surface of a cylindrical dielectric.
An inductively coupled plasma generation source that generates plasma by applying a high frequency power of 0 KHz or more and 50 MHz or less can be used. In addition, an electrode of a spiral coil is arranged on the atmospheric side of a disk-shaped dielectric, and one spiral electrode is provided on the spiral coil electrode.
An inductively coupled plasma generation source that generates plasma by applying a high-frequency power of 00 KHz or more and 50 MHz or less can also be used.

Further, a plate-like electrode is arranged inside the reactive gas plasma generating section, and the plate-like electrode is set at 100 KHz.
A capacitively-coupled plasma generation source that generates plasma by applying a high-frequency power of 50 MHz or less can also be used. A coil-shaped electrode or a spiral-shaped coil electrode is arranged inside the reactive gas generating section, and 100 KH
A plasma source in which inductively-coupled plasma and capacitively-coupled plasma coexist by applying a high-frequency power of z to 50 MHz may be used.

In the reactive gas plasma generation chamber 63, helicon wave plasma can be generated.
In addition, the reactive gas plasma generation chamber 63 has 20 to 300
An external coil 71 or an internal coil 73 that forms a Gaussian magnetic field may be provided. With such a configuration, it is possible to increase the generation efficiency of the active species of the active species generating means 61.

The substrate holder 13 is electrically insulated from the vacuum chamber 11. This makes it possible to prevent abnormal discharge in the substrate. Further, members provided in the film forming process zones 20 and 40, for example, the shielding means 12 and 14 and a target shield for covering the target are provided with cooling means such as water cooling. As a result, the temperature of the substrate can be prevented from rising due to the plasma, and a high-quality thin film can be formed.

In the present invention, as shown in FIG. 9, the film forming process zones 20 and 40 and the reaction process zone 60 are used.
Means that the substrate holder 1 is formed in the same vacuum chamber 121
The substrate load chamber 123 for mounting the substrate 141 on the substrate 43
And a substrate unloading chamber 125 for detaching the substrate from the substrate holder 143. The substrate loading chamber 123 and the vacuum chamber 121, and the substrate unloading chamber 125 and the vacuum chamber 121 are connected via pressure-separable shutoff means 131 and 135, respectively.

Each of the substrate loading chamber 123, the vacuum chamber 121, and the substrate unloading chamber 125 has its own evacuation means rotary pump (RP). Between them, a substrate holder conveying means for conveying the substrate holder 143 is provided. In the substrate loading chamber 123 and the substrate unloading chamber 125, other pre-processing and post-processing may be performed as necessary.

[0049]

An embodiment of the present invention will be described below with reference to the drawings. The members, arrangements, and the like described below do not limit the present invention, and can be variously modified within the scope of the present invention.

FIGS. 1 and 2 are explanatory views showing a method and an apparatus for forming a thin film according to the present invention. FIG. 1 is a top view partially sectioned for easy understanding, and FIG. A
It is a side view along -BC. In this example, magnetron sputtering, which is an example of sputtering, is used. However, the present invention is not limited to this, and other known sputtering such as bipolar sputtering without using magnetron discharge can be used.

The apparatus for forming a metal compound thin film according to this embodiment includes a vacuum chamber 11 and a shielding plate 1 serving as shielding means in the vacuum chamber 11.
Film forming process zones 20, 40 formed in 2, 14
And magnetron sputtering targets 29a, b, 49a, b as sputtering targets disposed in the film forming process zones 20, 40, and the vacuum chamber 11
The main constituent elements are a reaction process zone 60 formed by a shielding plate 16 as a shielding means therein, and a substrate holder 13 in which a substrate is arranged so as to face the film formation process zones 20, 40 and the reaction process zone 60. And

The vacuum chamber 11 is formed of a generally rectangular parallelepiped hollow body made of stainless steel, which is generally used for sputtering. An exhaust pipe is connected to the bottom surface of the vacuum chamber 11, and a vacuum pump 15 capable of exhausting the inside of the vacuum chamber 11 is connected to the pipe, as shown in FIG. This vacuum pump 15
And a controller not shown, the degree of vacuum in the vacuum chamber 11 can be adjusted.

The film forming process zones 20 and 40 are provided in a vacuum chamber 11 as shown in FIG. The film forming process zone 20 is surrounded by the shielding plate 12 and the substrate holder 13, and the film forming process zone 40 is surrounded by the shielding plate 14 and the substrate holder 13. In this example, two film forming process zones are provided, but the present invention is not limited to this, and one or three or more film forming process zones may be provided. In this example, since two film forming process zones are provided, it is also possible to sputter two different substances for each film forming process zone.

The shielding plate 12 is made of a flat plate made of stainless steel, and four shielding plates 12 are vertically arranged on the wall surface of the vacuum chamber 11 so as to surround the film forming process zone 20. A water cooling pipe (not shown) is attached to the shield plate 12, and the shield plate 12 is configured to be coolable. The configuration of the shielding plate 14 is the same as that of the shielding plate 12 except that it surrounds the film forming process zone 40.

Each of the film forming process zones 20 and 40 has a mass flow controller 2 as a gas introducing means.
5, 45 are arranged via piping. The mass flow controllers 25 and 45 include sputter gas cylinders 27 and 47 for storing argon gas as an inert gas,
It is connected to a reactive gas cylinder 79 for storing oxygen gas, nitrogen gas, fluorine gas, etc. as a reactive gas. The reactive gas is configured to be introduced from the reactive gas cylinder 79 into the film forming process zones 20 and 40 through the piping under the control of the mass flow controllers 25 and 45.

In the film forming process zone 20, magnetron sputtering electrodes 21a and 21b are arranged. The magnetron sputtering electrodes 21a and 21b are fixed to the vacuum chamber 11 at a ground potential via an insulating member (not shown).
Therefore, the sputtering electrode 21a and the target 2
9a, sputtering electrode 21b, target 29b
Are electrically separated from each other. The magnetron sputtering electrodes 21a and 21b are connected to an AC power supply 23 via a transformer 24 so that an alternating electric field can be applied. A plurality of two targets 29a and 29b made of a thin film material metal are fixed to the surfaces of the magnetron sputtering electrodes 21a and 21b on the substrate holder 13 side. Also,
In the film forming process zone 40, targets 49a, 49
b is arranged similarly to the targets 29a and 29b. Targets 29a, 29b, 49a, 49b
Is formed as a substantially disk-shaped body made of a vapor deposition material.

The targets 29a, 29b, 49a, 49
b and the substrate holder 13, a target 29a,
A target shield (not shown) that is movable so as to cut off or open between the substrate holder 13 and 29b, 49a, 49b is arranged. At the start of sputtering, the target shield blocks the target 29a, 29b, 49a, 49b and the substrate holder 13 until the sputtering is stabilized, and after the sputtering is stabilized, the target 29a, 29b, 49a, 49b and the substrate holder 13 are turned off. Opening the gap between them allows the deposition on the substrate after the sputtering is stabilized. Cooling means such as water cooling is provided in peripheral members of the film forming process zones 20 and 40 such as the target shield in order to prevent adverse effects due to heat generation such as a rise in the temperature of the substrate.

The reaction process zone 60 is provided in the vacuum chamber 11 as shown in FIG. The film forming process zone 60 is surrounded by the shielding plate 16 and the substrate holder 13. The structure of the shielding plate 16 is the reaction process zone 6
It is the same as the shielding plate 12 except that it surrounds 0.
An opening is formed in the wall surface of the vacuum chamber 11 of the reaction process zone 60, and an active species generator 61 as a reactive gas plasma generating means is connected to this opening.

The active species generator 61 is also called a radical source, and has a reactive gas plasma generating chamber 63 formed of a quartz tube for generating reactive gas plasma, and a coil-shaped coil wound around the reactive gas plasma generating chamber 63. An electrode 65, a matching box 67, a high-frequency power supply 69 connected to the coiled electrode 65 via the matching box 67, a mass flow controller 77, a reactive gas cylinder 79 connected via the mass flow controller 77, Is provided.

Reactive gas plasma generation chamber 63 and vacuum chamber 1
A grid 81 is provided between the two. The grid 81 selectively passes only electrically neutral active species particles to the reaction process zone 60, while
It has a function of preventing charged particles from passing therethrough. This function is generated by charge exchange between ions and electrons in the plasma on the surface of the grid 81 and neutralization.

As the grid 81, a multi-aperture grid or a multi-slit grid can be used. FIG. 6 shows a multi-aperture grid 1
It is a top view which shows No. 01. The multi-aperture grid 101 is formed of a flat plate made of a metal or an insulator, and has holes 103 having a diameter of about 0.1 to 3.0 mm innumerable.

FIG. 7 is a plan view showing a multi-slit grid. Multi slit grid 111
Is a flat plate made of a metal or an insulator, and has a width of 0.1 mm.
Innumerable slits of about 1 to 1.0 mm are provided. Grids 101 and 111 have cooling pipes 105 and 11 respectively.
5 is provided, and is configured to be capable of cooling by water cooling.

A reactive gas such as oxygen gas is supplied from a reactive gas cylinder 79 via a mass flow controller 77 to a reactive gas plasma generation chamber 63, and high frequency power from a high frequency power supply 69 is supplied to a coil via a matching box 67. When applied to the electrode 65 in the shape of a circle, a plasma of a reactive gas is generated in the reactive gas plasma chamber 63.

As shown in FIGS. 1 and 2, the external magnet 71 is disposed outside the reactive gas plasma generation chamber 63, and the internal magnet 73 is disposed outside the grid 81 in the reaction process zone 60. Are located in The external magnet 71 and the internal magnet 73 are connected to the plasma generator 20 to 300.
It has the function of generating high-density plasma by forming a Gaussian magnetic field and increasing the generation efficiency of active species.
In this example, both the external magnet 71 and the internal magnet 73 are provided, but any one of the external magnet 71 and the internal magnet 73 may be provided.

In this example, the reactive gas plasma section is
As shown in FIGS. 1 and 2, an inductively coupled plasma source having electrodes provided outside or inside a reactive gas plasma generation chamber is used. It is also possible to use an inductively coupled plasma source provided with a coil electrode ((1) below), a capacitively coupled plasma source ((2) below), a mixed inductively coupled / capacitively coupled plasma source ((3) below), or the like. .

(1) Plasma source shown in FIG. 3: A spiral (mosquito coil) coil electrode 91 is arranged on the atmosphere side of a reactive gas plasma generation chamber 63 made of a dielectric material such as a disk-shaped quartz glass. The spiral coil electrode 91 has a frequency of 100 KHz to 50 KHz.
An inductively coupled plasma generation source that generates plasma by applying high-frequency power of MHz. FIG. 3B is a schematic explanatory diagram of a plane of the spiral coil electrode 91. (2) Plasma source shown in FIG. 4: A plate-like electrode 93 is arranged inside the reactive gas plasma generation chamber 63, and a plasma is generated by applying high-frequency power of 100 KHz to 50 MHz to the plate-like electrode 93. Capacitively coupled plasma source. (3) Plasma source shown in FIG. 5: reactive gas generation chamber 63
A plasma source in which a coil-shaped electrode 95 or a spiral-shaped coil electrode is disposed inside, and a high-frequency power of 100 KHz to 50 MHz is applied to these electrodes to generate plasma in which inductively-coupled plasma and capacitively-coupled plasma coexist. . Etc. can be used. In addition, by adjusting the shape of the coil and the like, a helicon wave plasma source can be used to increase the generation efficiency of active species in the plasma.

Hereinafter, a procedure for forming a multilayer anti-reflection film using the apparatus of this embodiment will be described by taking as an example a case of forming a multilayer anti-reflection film in which silicon oxide and titanium oxide are laminated. The substrate is set on the substrate holder 13. As the targets 29a and 29b, a silicon target whose oxide has a low refractive index is used.
21b. As the targets 49a and 49b, a titanium target whose oxide has a high refractive index is fixed to the magnetron sputtering electrodes 41a and 41b. The pressure inside the vacuum chamber 11 is reduced to a predetermined pressure.

After that, the pressure in the film forming process zone 20 is adjusted to 1.0 × 10 ^{−1 to} 1.3 Pa. The rotation of the substrate holder 13 is started by operating the motor 17.
An argon gas as an inert gas for sputtering and an oxygen gas as a reactive gas are introduced into the film forming process zone 20 from the sputtering gas cylinder 27 and the reactive gas cylinder 79 by adjusting the flow rate with the mass flow controller 25, and the film forming process is performed. The sputtering atmosphere in the zone 20 is adjusted. At this time, the flow rate of each gas introduced into the film forming process zone 20 is about 300 scc of argon gas.
m, oxygen gas is 15 to 24 sccm.

Then, the frequency 1 is applied to the sputtering electrodes 21a and 21b from the AC power source 23 via the transformer 24.
交流 100 KHz AC voltage is applied to the target 29.
The alternating electric field is applied to a and 29b. Thus, at a certain point, the target 29a becomes a cathode (negative pole), and at that time, the target 29b always becomes an anode (plus pole). When the direction of the alternating current changes at the next time, the target 29b becomes the cathode (minus pole) and the target 29a becomes the anode (plus pole). Thus, the pair of targets 29
As a and 29b alternately become an anode and a cathode, plasma is formed, and a target on the cathode is sputtered.

At this time, non-conductive or low-conductive silicon imperfect oxide, silicon oxide, or the like may adhere to the anode, but when the anode is converted to a cathode by an alternating electric field, these silicon may be removed. Incomplete oxides and the like are sputtered, and the target surface returns to its original clean state. By repeating this, a stable anode potential state is always obtained, a change in plasma potential (generally, substantially equal to the anode potential) is prevented, and a silicon incomplete oxide ultrathin film is stably formed. in this way,
Power is supplied from the AC power supply 23 for sputtering, and silicon is sputtered to deposit an ultrathin metal imperfect oxide thin film such as SiO _x (x <2) on the substrate.

Simultaneously with the sputtering in the film forming process zone 20, the reaction process zone 60
Oxygen gas as a reactive gas is introduced from the reactive gas cylinder 79. 100 KHz to 50 for the coiled electrode 65
A high frequency power of MHz is applied, and the active species generator 61 generates plasma. The reaction process zone 6
The pressure of 0 is maintained at 0.7 × 10 ^{−1 to} 1.0 Pa. In the plasma in the reactive gas plasma generation chamber 63, oxygen gas ions and electrons as charged particles and radicals / atoms / molecules in a radical / excited state which are active species of an electrically neutral reactive gas are contained. Exists. The active species of the latter electrically neutral reactive gas are selectively or preferentially guided to the reaction process zone 60 by the grid 81.

Then, when the substrate holder 13 is rotated and the substrate is in the film forming process zone 20, the substrate on which the incomplete metal oxide thin film SiO _x (x <2) is formed is moved to the reaction process zone 60. When entering, the ultra-thin film is completely oxidized by active species of oxygen gas and converted into SiO ₂ . In this manner, by rotating the substrate holder 13 on which the substrate is mounted, the formation of the incomplete metal oxide ultrathin film SiO _x (x <2) in the film formation process zone 20 and the formation of the SiO ₂ in the reaction process zone 60 are performed. conversion is repeated, SiO ₂ having a desired thickness is formed on the substrate. Note that SiO ₂ may be used for the target 21. Unlike the RF and DC reactive sputtering method using the conventional compound target, in the present invention, the target 21 is made of SiO 2.
_{Even if 2} is used, oxygen deficiency is compensated in the reaction process zone 60, so that stable film formation of SiO ₂ can be performed. Then, the sputtering AC power supply 23 is turned off.

The pressure in the film forming process zone 240 is
It is adjusted to 1.0 × 10 ^{−1 to} 1.3 Pa. While adjusting the flow rate with the mass flow controller 45, an argon gas as an inert gas from the sputtering gas cylinder 47 and an oxygen gas as a reactive gas from the reactive gas cylinder 79 are introduced into the film forming process zone 40. At this time, the flow rate of each gas introduced into the film forming process zone 20 is:
About 300 sccm of argon gas and 15 to 2 oxygen gas
4 sccm. An AC voltage having a frequency of 1 to 100 KHz is applied from a sputtering
The alternating electric field is applied to a and 49b. Titanium is sputtered to begin depositing an ultrathin metal imperfect oxide thin film such as TiO _x (x <2) on the substrate.

At the same time, oxygen gas as a reactive gas is introduced from the reactive gas cylinder 79 into the reaction process zone 60, and the active species generator 61 is operated to generate active species of oxygen gas. When the substrate holder 13 rotates, an ultrathin metal oxide thin film TiO _x (x <2) is formed on the substrate in the film formation process zone 40, and the ultrathin film is formed of oxygen gas in the reaction process zone 60. It is completely oxidized by the active species and converted to TiO ₂ .

As described above, the substrate holder 1 on which the substrate is mounted
3, the formation of the ultrathin metal oxide thin film TiO _x (x <2) in the film formation process zone 40 and the conversion to TiO ₂ in the reaction process zone 60 are repeated, and the desired film is formed on the substrate. Thick TiO ₂ is formed. This step of forming SiO ₂ and the step of forming TiO ₂ are repeated, and an SiO ₂ thin film and a Ti
A multilayer anti-reflection film in which the O ₂ thin film is laminated is formed.

In this example, silicon and titanium are used as the targets 29a, b, 49a, and 49b. However, the present invention is not limited to this.
l), titanium (Ti), zirconium (Zr), tin (Sn), chromium (Cr), tantalum (Ta), silicon (Si), tellurium (Te), nickel chromium (Ni
-Cr) or a metal target such as indium tin (In-Sn) can be used. Compounds of these metals, for example, Al ₂ O ₃ , TiO ₂ , ZrO ₂ ,
Ta ₂ O ₅ , SiO ₂ , Nb ₂ O ₅ or the like can also be used.

When these targets are used, exposure to the reactive species of the reactive gas in the reaction process zone 60 causes Al ₂ O ₃ , TiO ₂ , ZrO ₂ , Ta ₂ O ₅ ,
Optical film or insulating film such as SiO ₂ , Nb ₂ O ₅ , ITO
, A magnetic film such as Fe ₂ O ₃ , TiN, Cr
It is a super hard film of N, TiC or the like. TiO ₂ , Zr
Insulating metal compounds such as O ₂ and SiO ₂ have extremely low sputtering rates and poor productivity compared to metals (Ti, Zr, Si), so the dual magnetron sputtering method of the present invention is particularly effective. .

By using targets of different metals or metal compounds for the targets 29a and 29b and the targets 49a and 49b, a multilayer antireflection film in which different metal compounds are laminated, for example, a multilayer of SiO ₂ and ZrO ₂ is formed. It is also possible to form an antireflection film, a multilayer antireflection film of SiO ₂ and Ta ₂ O ₅ , a multilayer antireflection film of SiO ₂ and Nb ₂ O _5, and the like.

In this example, as shown in FIG. 11, the film forming process zones 20 and 40 and the reaction process zone 60 are used.
Although the configuration is such that the reactive gas is introduced from the same reactive gas cylinder 79, the present invention is not limited to this. The film forming process zones 20 and 40 and the reaction process zone 60 are different. It is also possible to connect gas cylinders and introduce different gases having the same element.

The targets 29a and 29b may be the same metal target or different metal targets.
When the same metal target is used, a metal incomplete oxide ultrathin film made of a single metal is formed, and when different metal targets are used, a metal incomplete oxide ultrathin film made of an alloy is formed. The same applies to the targets 49a and 49b.

As the reactive gas introduced into the film forming process zones 20 and 40 and the reaction process zone 60, in addition to the oxygen introduced in this embodiment, ozone, nitrous oxide (N ₂
An oxidizing gas such as O), a nitriding gas such as nitrogen, a carbonizing gas such as methane, and a fluorinating gas such as fluorine and carbon tetrafluoride (CF ₄ ) can be used. When nitrogen gas is introduced into the film forming process zones 20 and 40, the flow rate of the gas introduced into the film forming process zones 20 and 40 is 300 sccm of an argon gas as an inert gas and 9 to 6 of a nitrogen gas.
It is good to be 0 sccm.

Hereinafter, according to this example, SiO ₂ and Ta ₂
The operating conditions when a multilayer antireflection film with O ₅ or Nb ₂ O ₅ is formed are shown. (1) Sputtering conditions (Si) Input power: 7.0k
W Substrate temperature: room temperature Pressure in the film formation process zone: 1.3 Pa Applied AC voltage frequency 40 KHz Substrate holder rotation speed: 100 rpm Ultrathin film thickness: 2 to 6 Å (2) Sputtering conditions (Ta / Nb) Input power: 5 0.0 kW Substrate temperature: room temperature Pressure in film forming process zone: 1.3 Pa Applied AC voltage frequency 40 KHz Substrate holder rotation speed: 100 rpm Thickness of ultra-thin film: 1-4 Å (3) Driving conditions of active species generator (O ₂ ) Apparatus: Inductively coupled plasma generation source shown in FIGS. 1 and 2 Input power: 2.0 kW Pressure: 6.5 × 10 ⁻¹ Pa

FIG. 8 is a graph showing the relationship between the damping coefficient of the thin film formed by the method of forming a metal compound thin film of the present example and the film forming speed. Sample A (with O ₂ ) in FIG. 8 is a graph of a thin film formed by the method for forming a metal compound thin film of this example using the apparatus for forming a metal compound thin film shown in FIG. It is formed under the operating conditions (1) to (3). Further, the sample B (O ₂
No) is a comparative example. Specifically, the film forming process zones 20, 40 of the metal compound thin film forming apparatus shown in FIG.
4 is a graph of a metal compound thin film formed without introducing a reactive gas into the thin film. Other configurations of the thin film forming apparatus and the forming method of the sample B are the same as those of the sample A according to the present embodiment.
According to (3).

FIG. 8 shows that the method of forming a metal compound thin film of this example according to sample A has the same film forming rate as the method of forming a metal compound thin film of sample B in comparison. It was found that a thin film having a low attenuation coefficient was formed. That is, according to the method for forming a metal compound thin film of the present example, compared with a comparative method in which no reactive gas is introduced into the film forming process zone, even if the film forming speed is the same, optical absorption is small. It was found that a thin film could be obtained. Further, as shown in FIG. 10, it is known that according to the method for forming a metal compound thin film of this example, a film formation rate substantially similar to that of the conventional twin magnetron sputtering method can be obtained.

FIG. 9 is a plan view showing another embodiment of the present invention. The apparatus has a film forming chamber 12 as a vacuum chamber as a whole.
1, a substrate loading chamber 123 before and after the substrate loading chamber, and a substrate unloading chamber 125. Each chamber has an individual exhaust system, RP indicates a rotary pump, and TMP indicates a turbomolecular pump. Gate valve 1 between each room
31 and 133 are connected. Substrate loading room 1
23 can be opened to the atmosphere by a gate valve 135 or an opening / closing door, and the substrate unload chamber 125 can be opened to the atmosphere by a gate valve 137 or an opening / closing door.
That is, each chamber is pressure-isolated and has its own exhaust system, and the substrate holder 143 can be transferred through the gate valves 131 and 133.

A substrate holder 143 on which a substrate 141 is mounted
Is carried into the substrate load chamber 123 through the gate valve 135, and the substrate load chamber 123 is evacuated by a rotary pump to undergo pretreatment such as heating.
That is, the substrate loading chamber 123 is a chamber for performing a pre-processing function of attaching / detaching / exhausting / necessary substrate holder. After this processing is completed, the substrate holder 143 is transferred to the film forming chamber 121. In the film forming chamber 121, a thin film is formed on the substrate 141. In order to avoid complexity, the film forming chamber 1 is shown in the drawing.
Only the substrate holder 143 in 21 is shown by a dashed line, and the illustration of the substrate 141 is omitted.

The substrate holder 143 on which the film forming process has been completed is conveyed to the substrate unloading chamber 125, subjected to post-processing if necessary, and taken out through the gate valve 137. That is, the substrate unloading chamber 125 is a chamber for performing desorption / evacuation / subsequent post-processing of the substrate holder. The film forming process in the film forming chamber 121 is the same as the embodiment shown in FIGS. 1 and 2 except that the substrate holder has a horizontal plate shape.

[0088]

As described above, according to the present invention, a metal compound thin film having stable characteristics can be formed at a high speed with a simple structure and operation. It is known that strong stress is generated in a metal thin film. However, in the method for forming a metal compound thin film according to the present invention, first, an ultra-thin metal incomplete reactant film is formed, and then the ultra-thin metal compound thin film is formed. Since a reaction mechanism for sequentially converting the metal ultra-thin film is adopted, it is possible to form a thin film having a smaller stress as compared with the conventional method of converting a metal ultra-thin film into a metal compound ultra-thin film. Further, a high-quality metal compound thin film having little optical absorption can be formed at a high speed.

Further, formation of an ultrathin metal incompletely reacted product,
By repeatedly performing the conversion to the metal compound ultrathin film, the metal compound ultrathin film is deposited a plurality of times, so that a thin film having a desired film thickness can be formed at a high speed at a low substrate temperature. By adopting the dual-maggrotron sputtering method as a method of forming an ultrathin metal reactant thin film, it is possible to secure a stable anode part, prevent a change in anode potential, and form a good-quality thin film with good reproducibility. .

In converting an ultrathin metal reactant ultrathin film into an ultrathin metal compound film, the active species such as radicals, radicals in excited state, atoms or molecules are utilized to make a comparison with the case where charged particles are used. As a result, the thin film can be prevented from being damaged and the substrate temperature can be prevented from rising, so that a thin film having good characteristics can be efficiently obtained. The film formation process zone and the reaction process zone are separated by the shielding means, and the discharge for sputtering and the discharge for generation of the active species of the reactive gas can be individually controlled. A thin film can be formed.

[Brief description of the drawings]

FIG. 1 is an explanatory top view showing an embodiment of an apparatus used in the present invention.

FIG. 2 shows an embodiment of the apparatus used in the present invention, FIG.
FIG. 5 is a cross-sectional view taken along line ABC of FIG.

FIG. 3 is an explanatory diagram showing a configuration example of a plasma source.

FIG. 4 is an explanatory diagram showing a configuration example of a plasma source.

FIG. 5 is an explanatory diagram showing a configuration example of a plasma source.

FIG. 6 is a plan view showing a multi-aperture grid.

FIG. 7 is a plan view showing a multi-slit grid.

FIG. 8 is a graph showing a relationship between a damping coefficient and a deposition rate of a thin film formed by the method for forming a metal compound thin film of the present example.

FIG. 9 is an explanatory plan view showing an embodiment of an apparatus used in the present invention.

FIG. 10 is an explanatory diagram showing a relationship between a reactive gas ratio and a film formation rate.

FIG. 11 is an explanatory view when a composite metal compound thin film is formed on a substrate.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 11 Vacuum tank 12, 14, 16 Shielding plate 13 Substrate holder 15 Vacuum pump 17 Motor 20, 40 Deposition process zone 21a, 21b, 41a, 41b Sputtering electrode 23, 43 AC power supply for sputtering 24 Transformer 25, 45 Mass flow controller 27, 47 Sputter gas cylinder 29a, 29b, 49a, 49b Target 60 Reaction process zone 61 Active species generator 63 Reactive gas plasma generation chamber 65 Electrode 67 Matching box 69 High frequency power supply 71 External coil 73 Internal coil 77 Mass flow controller 79 Reactive gas cylinder 81 Grid 91 spiral electrode 93 plate electrode 95 coil electrode 101 multi-aperture grid 103 hole 105 cooling tube 111 multi-slit grid 113 slit 15 Cooling pipe 121 Film deposition chamber 123 Substrate load chamber 125 Substrate unload chamber 131, 133, 135, 137 Gate valve 141 Substrate 143 Substrate holder 151, 161, 171 Shielding plate 153, 163 Film deposition process zone 155a, 155b, 165a, 165b Target 173 Reaction process zone 175 Active species generator

 ──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Takeshi Sakurai 3-2-6 Minamioi, Shinagawa-ku, Tokyo Inside Shincron Co., Ltd. (72) Inventor Kazuhiko Maruta 3-2-2 Minamioi, Shinagawa-ku, Tokyo Stock In Syncron Co., Ltd. (72) Inventor Kazuhiro Endo 3-2-6 Minamioi, Shinagawa-ku, Tokyo F-term (reference) 4K029 AA24 BA17 BA35 BA43 BA46 BA48 BB02 BC07 CA05 DA10 DC05 DC16 DC28 DC29 DC31 DC39 DC43 DC48 JA08 5F103 AA08 BB46 DD27 DD28 NN06 RR01 RR04 RR05

Claims (8)

[Claims] 1. A plurality of sputtering targets electrically insulated from a ground potential, such that each target alternates between a cathode and an anode so that at the same time one target is a cathode and one target is an anode. A step of applying an AC voltage, introducing an inert gas and a reactive gas, and forming an ultra-thin metal incomplete reactant thin film comprising an incomplete metal reactant on a substrate in a film forming process zone in a vacuum chamber. And contacting an active species of an electrically neutral reactive gas with the ultrathin metal reactant ultra-thin film in a reaction process zone spatially and pressure-separated from the film formation process zone in the vacuum chamber. Causing the ultra-thin metal incomplete reactant to react with the active species of the reactive gas to convert the ultra-thin metal compound into a metal compound ultra-thin film; Forming a plurality of metal compound ultra-thin films and depositing the metal compound ultra-thin film by depositing the metal compound ultra-thin film into a substrate. A method for forming a metal compound thin film, comprising: 2. The active species of the electrically neutral reactive gas includes at least one of a radical, a radical in an excited state, an atom in an excited state, and a molecule in an excited state. The method for forming a metal compound thin film according to the above. 3. A grid for introducing an active species of an electrically neutral reactive gas into a reactive gas by generating a reactive gas plasma by introducing the reactive gas and selectively passing an electrically neutral active species. 2. The method for forming a metal compound thin film according to claim 1, wherein the metal compound thin film is introduced into the vacuum chamber through the step. 4. An apparatus for forming a metal compound thin film on a substrate by sputtering, comprising: gas introduction means for introducing a reactive gas and an inert gas; and electrically insulated from a ground potential and connected to an AC power supply. A plurality of sputtering targets capable of alternately applying a positive potential and a negative potential by the AC power source were provided, and were formed in a vacuum chamber for performing a step of forming an ultrathin metal incomplete reactant on the substrate. A film formation process zone, and means for generating an electrically neutral reactive gas active species, and reacting the ultra-thin metal incomplete reactant thin film with the active species of the reactive gas to convert it into a metal compound ultra-thin film A reaction process zone formed in a vacuum chamber for performing a step of causing the substrate to be transferred between the film formation process zone and the reaction process zone; Metallic compound thin film forming apparatus characterized by comprising spatially the deposition process zone and said reaction process zone, and a shielding means for the pressure separated. 5. The apparatus according to claim 4, wherein the film forming process zone and the reaction process zone are formed in the same vacuum chamber. 6. The reactive gas generating means includes a reactive gas introducing means for introducing a reactive gas, a reactive gas plasma generating means connected to a power supply for applying a voltage, and the reactive gas plasma. 5. The apparatus for forming a metal compound thin film according to claim 4, further comprising a grid for selectively passing an electrically neutral active species in the reactive gas plasma generated by the generating means. 7. The metal compound thin film forming apparatus according to claim 4, wherein said substrate holder is electrically insulated from said vacuum chamber. 8. The substrate processing chamber, wherein the film forming process zone and the reaction process zone are formed in the same vacuum chamber, and a substrate load chamber for mounting the substrate on the substrate holder; A substrate unloading chamber for performing detachment, wherein the substrate loading chamber and the vacuum chamber, and the substrate unloading chamber and the vacuum chamber are respectively connected via pressure-separable blocking means, The chamber, the vacuum chamber, and the substrate unloading chamber each have their own exhaust means, and the substrate holder transports the substrate holder between the substrate loading chamber, the vacuum chamber, and the substrate unloading chamber. 5. The apparatus for forming a metal compound thin film according to claim 4, wherein a conveying means is provided.