JPH09217171A - Manufacture of ito transparent conductive film - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent the occurrence of an abnormal discharge, such as tracking arc, and execute stable film formation in the manufacture of an ITO transparent conductive film by a high-frequency magnetron sputtering method. SOLUTION: The high-frequency magnetron sputtering method comprises forming the ITO transparent conductive film consisting of In, Sn and O on a substrate by using the oxide of In and Sn as a object, providing the rear surface of the object with a magnet, supplying high-frequency electric power to the object in an atmosphere introduced with only the rare gas or the rare gas and oxygen, converging plasma near to the objective surface and utilizing a sputtering phenomenon. The supply of the high-frequency electric power is periodically stopped to alternately form the supply period and the supply stop period. The time of the supply period is shorter than the time required for the occurrence of the abnormal discharge. Namely, the high-frequency electric power is intermittently supplied.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for producing an ITO transparent conductive film, and more particularly, it improves a high frequency power supply method in a step of producing an ITO transparent conductive film by using a high frequency magnetron sputtering method, and improves tracking power supply such as tracking arc The present invention relates to a method for preventing the occurrence of abnormal discharge.

[0002]

2. Description of the Related Art A high-frequency magnetron sputtering method is a sputtering method in which a magnet is arranged on the back surface of a target in order to focus plasma near the surface of the target to improve the film formation rate and to supply high-frequency power to the target. Is the law. The sputtering method is a well-known thin film forming method. In a vacuum chamber, a rare gas such as argon or a mixed gas of a rare gas and a reactive gas (eg, oxygen or nitrogen) is introduced and power is supplied to the target. Plasma is generated by utilizing the sputtering phenomenon to form a thin film having a target constituent element as a basic constituent element on the substrate.

Indium (I
n), tin (Sn), and oxygen (O), an ITO transparent conductive film is produced by using a target made of an oxide of In and Sn. Since the target is conductive, the cost is currently low. The DC magnetron sputtering method is used because of its low temperature and good controllability. However, a transparent electrode for a liquid crystal display device, which is a main use of the ITO transparent conductive film, requires a film having a resistivity lower than that of a film obtained by the DC magnetron sputtering method as the performance of the liquid crystal display device is improved. .

Therefore, the present inventors have prepared an ITO transparent conductive film using an oxide of In and Sn as a target.
Using the high-frequency magnetron sputtering method rather than the direct current magnetron sputtering method has a lower specific resistance,
It was found that a good film with high transmittance can be formed (for example, Proceedings of the 41st Joint Lecture on Applied Physics, 370 pages, Lecture No. 28p-ME-14, (1994)).

[0005]

In the high frequency magnetron sputtering method, the occurrence of abnormal discharge (arc) on the target and on the surface of other members inside the vacuum chamber poses a problem. In particular, the oxides of In and Sn are used as targets, and I
When the TO transparent conductive film is formed, a unique abnormal discharge occurs in which the arc rotates on the target where the magnetic field component perpendicular to the target surface is zero (the part where the target is most etched). This abnormal discharge is called a tracking arc.

When an abnormal discharge occurs, the impedance of the discharge changes, power is not efficiently supplied to the target, and the film deposition rate decreases or no film is formed. In some cases, a film having completely different characteristics may be formed due to the occurrence of abnormal discharge. In particular, when a tracking arc occurs, the potential of the target becomes positive, the target is not sputtered, and other members are sputtered. For this reason, on the contrary, even if a film is formed on the target, or even if a film is formed on the substrate, an opaque film having a high specific resistance is formed.

Further, when abnormal discharge occurs on the substrate, that portion becomes a defect and directly causes a product defect.

Further, the occurrence of abnormal discharge also causes the generation of particles, and if the generated particles adhere to the substrate, they become defects, resulting in defective products.

The tracking arc is less likely to occur by weakening the magnetic field intensity on the target surface, increasing the sputtering pressure, and decreasing the supply power. Further, by increasing the sputtering pressure or decreasing the power supply, it becomes difficult to generate an arc other than the tracking arc. However, these methods cannot completely suppress the occurrence of abnormal discharge. Furthermore, in these methods, the film forming rate is reduced, which poses a problem in terms of productivity.

A technique relating to suppression of abnormal discharge in the high frequency magnetron sputtering method is disclosed in, for example, Japanese Unexamined Patent Publication No. 7-258845. The sputtering method disclosed in this publication has a problem that the structure of the power supply for supplying electric power is complicated and the control is difficult, and there is no description about the tracking arc, and the problem of suppressing the tracking arc is not solved.

An object of the present invention is to prevent abnormal discharge such as tracking arc from occurring in the production of an ITO transparent conductive film by a high frequency magnetron sputtering method using In and Sn oxides as targets, and to form a stable film. It is to provide a method for producing an ITO transparent conductive film that can be performed.

[0012]

[Means and Actions for Solving the Problems] First,
The knowledge that has led to the configuration of the present invention as a means for achieving the above object will be described.

The cause and mechanism of the occurrence of the tracking arc have not been clarified at present. The causes of abnormal discharges other than tracking arcs are particles, redeposited films and nodules (projections) on the target, floating potential members, conductive or insulating films attached to the substrate, and ground potential members. It is considered that the cause is a high resistance or insulating film formed on the substrate. In any case, if they are not electrically connected to the cathode or a grounded member, they will be charged up and cause a potential difference from the cathode potential (self-bias) or the ground potential, and the abnormal discharge occurs due to the potential difference. Is expected.

The present inventors have made earnest studies to solve the problem of abnormal discharge, particularly tracking arc, in the production of an ITO transparent conductive film by the high frequency magnetron sputtering method using In and Sn oxides as targets. As a result, the following two ideas have been reached regarding the cause and mechanism of the occurrence of the tracking arc.

The first idea is that particles or redeposited film adhered to the target are the causes. Particles or films are insulators or high resistance,
In addition, even a conductive material may have a high contact resistance with the target due to its weak adhesion. In such a case, they are charged up to generate a potential difference with the cathode potential (self-bias), and this potential difference causes an arc. When an arc occurs, the charged up object attached to the target can move.
The charged up thing that became able to move is trapped in the magnetic field of the magnet placed on the back of the target due to the charge that it has, and drifts the part where the target is most etched. Along with this drift, the arc also drifts.

The second idea is that particles or sputtered particles floating in the discharge space gather at the interface with the cathode sheath in the plasma with the discharge time, forming clusters and negatively charging (in this regard, SJChoi Etc. AMERICAN VACUUM SOCIETY, 3
8th National Symposium, Final Program, p77, Lecture No. PS-MoM6, (1991)). Since this cluster is charged, it is trapped by the magnetic field of the magnet placed on the back surface of the target, and concentrates on the part where the target is most etched, and drifts this part. Then, the cluster grows while drifting and is further charged, so that an arc is generated at a certain point due to the potential difference with the cathode. This arc also drifts because the charged cluster is drifting.

Before the occurrence of the tracking arc, it takes time for charging as in the case of abnormal discharge other than the tracking arc. This is apparent from the fact that the tracking arc did not occur at the same time as the start of high-frequency power supply (that is, the start of discharge) in the study.

Therefore, the present invention aims to solve the problem by providing a time for relaxing the charging before the abnormal discharge such as the tracking arc occurs.

To alleviate the charging, it is desirable to stop the discharge. Further, it is not always necessary to completely stop the discharge in order to alleviate the charging. The present inventors have conducted research and found that even when a tracking arc is generated, the sustained tracking arc can be stopped by reducing the high frequency power to some extent. Furthermore, we found that even if the high frequency power was reduced to some extent and the persistent tracking arc was stopped and then the original high frequency power was increased again, the tracking arc did not occur immediately and stable discharge was possible for a while. . These means that even if the discharge is not completely stopped, the sustained tracking arc can be stopped and the charging can be alleviated if the plasma density is lowered to some extent. That is, if the plasma density is lowered to some extent before the tracking arc is generated, the charging can be alleviated even if the charging is performed so that the tracking arc is generated, and the generation of the tracking arc can be suppressed.

The present invention is constructed as follows based on the above findings.

I according to the first invention (corresponding to claim 1)
The TO transparent conductive film is produced by using an oxide of indium In and tin Sn as a target, and installing a magnet on the back surface of the target in an atmosphere in which only a rare gas or a rare gas and oxygen (O ₂ ) is introduced. , High frequency power is supplied to the target, plasma is converged near the surface of the target, and I
A method for forming an ITO transparent conductive film made of n, Sn, and O, wherein the supply of high-frequency power is periodically stopped to alternately create high-frequency power supply periods and supply stop periods, and to supply high-frequency power. The period of time is set to be shorter than the time required for occurrence of abnormal discharge. That is, the high frequency power is intermittently supplied to the target.

In the first aspect of the present invention, the period for supplying the high frequency power to the target and the period for stopping the supply of the high frequency power to alleviate the charging are repeated, and at this time, the high frequency power supply time is set. The abnormal discharge is prevented from occurring by making the time shorter than the time until the abnormal discharge occurs.

Here, the thin film formation by sputtering is generally performed at a film forming pressure of several mTorr (on the order of 10 ^-1 Pa). When the discharge start pressure is lower than the film forming pressure, in the intermittent supply of high-frequency power, the high-frequency power supply is stopped for a long time, and the discharge is completely stopped.
Discharge is possible at the next supply. However, depending on the apparatus, for example, when the size of the cathode (target) is small, the discharge start pressure may become higher than the film formation pressure. In such a case, if the high frequency power supply is stopped for a long time and the discharge is completely stopped, the discharge cannot be started at the film forming pressure even when the high frequency power is next supplied. Therefore, when such a discharge starting pressure is higher than the film forming pressure, it is desirable to prevent the discharge from completely stopping when the supply of the high frequency power is stopped.

I of the second invention (corresponding to claim 2)
In the method for producing the TO transparent conductive film, in the first invention, preferably, the supply stop time of the high frequency power is set to be shorter than the life of the plasma.

The plasma has a lifetime and does not disappear at the moment when the supply of high frequency power is stopped. This life depends on the type of gas in the plasma, the pressure, and the like, but in the case of argon (Ar) that is generally used for sputtering film formation, the film formation pressure is approximately 1 msec.
In the second aspect of the present invention, since the supply stop time of the high frequency power is set shorter than the life of such plasma, the discharge can be maintained at the film formation pressure even when the discharge start pressure is higher than the film formation pressure. Further, in the study by the present inventors, it was found that even when the supply stop time of the high frequency power was shorter than 1 msec, it was a sufficient time for alleviating the charging. Therefore, if the supply time of the high frequency power is set shorter than the time until the abnormal discharge occurs, the abnormal discharge can be prevented.

I of the third invention (corresponding to claim 3)
In the method for producing the TO transparent conductive film, in the first or second invention, helium gas is preferably added to the sputtering gas.

Some high frequency power supplies use vacuum tubes. Particularly, in order to obtain a high film forming speed, a large high frequency power is required, but a vacuum tube is currently used as a power supply capable of outputting a large power exceeding 5 kW. In a high frequency power supply using such a vacuum tube, it is difficult to make the supply stop time of the high frequency power shorter than the life of plasma. The third invention can address this problem. It is known that the metastable excited atom He ^* of He has high excitation energy and ionizes many particles in plasma by Penning ionization. It is known that the metastable excited atom He ^* has a long life and causes glow discharge at atmospheric pressure. Therefore, when He gas is added to the sputtering gas, the life of plasma is extended, so that the feature of the second invention can be realized even in a power source using a vacuum tube.

I of the fourth invention (corresponding to claim 4)
The method for producing the TO transparent conductive film is such that the high frequency power supplied to the target is periodically reduced under the same premise as in the first invention.

In the fourth aspect of the present invention, the period for completely stopping the supply of the high frequency power as in the first aspect of the invention is not provided, but the period is simply lowered. Therefore, the discharge does not stop and the discharge start pressure is reduced. Even when the pressure is higher than the film formation pressure, the discharge can be maintained at the film formation pressure. As is clear from the results of the research leading to the present invention described above, it is possible to reduce the plasma density by lowering the high-frequency power and thereby alleviate the charging. It can be prevented.

[0030]

Preferred embodiments of the present invention will be described below with reference to the accompanying drawings.

First, the first embodiment will be described. In this embodiment, an ITO transparent conductive film is formed by using a mixture of In and Sn oxides as a target.

FIG. 1 shows the configuration of only the high frequency power supply system to the cathode (that is, the target) in the high frequency magnetron sputtering apparatus. In FIG. 1, illustration of a vacuum container for a vacuum processing chamber, a substrate to be processed, a substrate transfer mechanism, a magnet arranged on the rear surface of the target, a vacuum exhaust device, a gas introduction mechanism, etc. is omitted for convenience.
The target 11 is arranged on the back plate 12. High frequency power is supplied from the high frequency power supply 14 to the target 11 through the impedance matching device 13. Generally 13.56 MHz for high frequency magnetron sputtering
Of high frequency is used. High frequency power supply 14 is 13.56M
It outputs high frequency power of Hz.

The structure and film forming conditions of the used high frequency magnetron sputtering apparatus are the same as those of the conventional apparatus. That is, in this apparatus, for example, a disk-shaped target 11 having a diameter of 8 inches is used, and as the target 11, a sintered compact target (for example, density 95%) in which SnO ₂ is added 10 wt% to In ₂ O ₃ is used. There is. Regarding the influence of the magnet on the target 11, the magnetic field strength parallel to the target surface is, for example, about 300 Gauss at the position where the magnetic field component perpendicular to the target surface (the upper surface of the target 11 in FIG. 1) becomes zero. The substrate is arranged so as to face the target surface, and the distance between them is set to, for example, 60 mm, which gives the most uniform film thickness distribution. In the above device configuration, the discharge starting pressure is 20 mTorr. Therefore, first, argon gas (Ar gas) is introduced and maintained as a sputtering gas in the vacuum processing chamber up to this pressure, and high frequency power having a desired voltage waveform whose waveform is controlled is supplied from the high frequency power source 14 to the target 11. Discharge is generated.

By the way, in the conventional device, the high frequency power having the continuous voltage waveform shown in FIG. 2 was supplied to the target to generate the discharge. In the case of the conventional device using the high frequency power of such a continuous voltage waveform, the high frequency power is 6
When set to 00W, if it is short, it takes about 3 minutes, and if it is long, it is 5 minutes.
An abnormal discharge occurred in about a minute. On the other hand, after starting discharge at a pressure of 20 mTorr with the same high frequency power of 600 W,
When the Ar gas introduction flow rate was reduced and the pressure was maintained at 10 mTorr, abnormal discharge occurred in about 1 minute when the pressure was short and about 3 minutes when the pressure was long. The abnormal discharge generated by the conventional device is
There were various things such as a tracking arc or an arc on the surface of a member other than the target.

In contrast to the above conventional case, the high frequency power supply 14 according to the present embodiment outputs the voltage waveform shown in FIG. 3 based on an output controller (not shown).
As is clear from FIG. 3, in this embodiment, for example, 600
The high frequency power supply of W is periodically stopped for the required time,
Therefore, high frequency power is intermittently supplied to the target 11. In FIG. 3, a is a period in which high frequency power of 13.56 MHz is supplied, and b is a period in which supply of high frequency power is stopped. The supply period a is set to 5 msec, for example, and the stop period b is set to 1 msec, for example. In FIG. 3,
This is a visual representation that the period a is in the state of an AC waveform, and there is no direct relationship between the wave number and time.

When the high-frequency power supply from the high-frequency power source 14 to the target 11 is set to the above condition, the Ar gas introduction flow rate is reduced to 1 even if the discharge starting pressure is 20 mTorr.
Even at 0 mTorr, abnormal discharge did not occur at all for a long time, and stable discharge could be generated. As a result, the ITO transparent conductive film could be formed with good reproducibility.

In the above embodiment, the reason why the abnormal discharge did not occur and the stable discharge was possible for a long time is that the time 5 msec of the power supply period a is the time until the abnormal discharge occurs, as compared with the result of the above-mentioned conventional device. However, the time of 1 msec of the stop period b was sufficient to alleviate the charging occurring within the time of the power supply period a.
Further, in this embodiment, it is lower than the discharge starting pressure of 10
The reason why the discharge could be maintained even at mTorr was that the life of the plasma was
This is because the period b for stopping the supply of high-frequency power was longer than 1 msec.

In the above-mentioned embodiment, the time of the period a for supplying the high frequency power is set to 5 msec, but this supply time may be shorter than the time until the abnormal discharge occurs, and is limited to the numerical value of this embodiment. Not something. Considering the results of the conventional device for comparison, the high-frequency power supply time can be set to about 3 minutes at a pressure of 20 mTorr and about 1 minute at a pressure of 10 mTorr at a power supply of 600 W. Is. However, since the time until the occurrence of abnormal discharge is shortened when the supplied power is high, it is necessary to shorten the time of the supply period a when the supplied power is high.

The time of the high frequency power supply stop period b is not limited to 1 msec in the above embodiment. The supply stop time may be longer or shorter than 1 msec as long as the charging that occurs during the supply period a is relaxed. In this embodiment, the minimum pressure that can maintain the discharge is 7 mTorr. This is because reducing the pressure shortens the life of plasma. Therefore, when it is desired to form a film at a pressure lower than this pressure, the period of the supply stop period b is shorter than the life of plasma, that is, 1 msec or more. Should also be shortened. However, if it is made too short, the charging that occurs within the time of the supply period a cannot be alleviated and abnormal discharge will occur, so the time of the supply stop period b is even when the film forming pressure is lower than the discharge start pressure. It is desirable to set the plasma at the limit of the life of the plasma so that the discharge can be maintained.

Here, when the high frequency power is increased or the high frequency power supply period a becomes longer, the supply stop period b necessary for alleviating the charging also becomes longer.
Therefore, it is necessary to adjust the time of the supply period a and the time of the supply stop period b. Furthermore, under the condition that the magnetic field strength on the target surface is high, the pressure is low, or the number of nodules on the target surface is increased, a tracking arc is likely to occur and the time until it occurs is short. Further, in an apparatus in which particles are easily generated, an arc is easily generated on a member other than the target. As described above, depending on the conditions of the device and the target surface and the process conditions, abnormal discharge is likely to occur and may occur within a few seconds. Therefore, it is desirable that the time of the high-frequency power supply period a is set substantially in the msec (millisecond) order, and at the longest in the 100 msec order as in the present embodiment.

Next, a second embodiment of the present invention will be described. In this embodiment, 5% of He gas is added to the Ar gas which is the sputtering gas in the first embodiment. In the above-described first embodiment, since the time of the period b for stopping the supply of the high frequency power is set to 1 msec, the discharge cannot be maintained at 7 mTorr or less. However, in the present embodiment, by adding He gas to the sputtering gas, the life of plasma is extended, and even if the stop period b is 1 msec, abnormal discharge does not occur up to a pressure of 2 mTorr, and stable discharge can be maintained. .

When He gas is added to the sputtering gas, the life of the plasma can be extended by increasing the amount of the He gas added or the pressure of the sputtering gas to increase the partial pressure of the He gas. Therefore, the method of adding He gas to the sputtering gas is effective when the time of the period b during which the supply of high frequency power is stopped cannot be set short with a power source using a vacuum tube or the like.

Next, a third embodiment of the present invention will be described. In this embodiment, except for the method of supplying high frequency power,
The conditions are the same as those described in the first embodiment. In the present embodiment, the high frequency power supplied to the target is periodically reduced instead of being periodically stopped. FIG.
3 shows a voltage waveform output from the high frequency power supply 14 according to the present embodiment. C in FIG. 4 is a normal high frequency power supply period, and d
Is the period during which the high frequency power is periodically reduced. The electric power in the period c is, for example, 600 W, the time is, for example, 5 msec, and the period is d.
The power is set to 250 W and the time is set to 2 msec, for example. Here, FIG. 4 shows visually that the periods c and d are AC waveforms, and there is no direct relationship between each wave number and time. Also in this embodiment,
Abnormal discharge did not occur at all for a long time, stable discharge was possible, and the ITO transparent conductive film was formed with good reproducibility. Further, in the method of supplying the high frequency power in the present embodiment, the power supply is not completely stopped, so the discharge does not stop, there is no abnormal discharge up to a pressure of 2 mTorr, and stable discharge can be maintained.

In the present embodiment, there is no abnormal discharge and stable discharge can be performed for a long time. One of the reasons is that, as in the case of the first embodiment, the time of the period c during which the high frequency power of 600 W is supplied. This is because 5 msec was sufficiently short with respect to the time until the occurrence of abnormal discharge. And, to another one, the supplied power of 250 W in the period d does not cause charging enough to cause abnormal discharge, and conversely, the charging generated in the period of time c in which the power of 600 W is supplied can be alleviated. This is because the. Also, the time of period d is 2 msec.
But it was enough.

In the present embodiment, the time of the period c in which the high frequency power of 600 W is supplied is set to 5 msec. However, the time of the supply period c may be shorter than the time until the abnormal discharge occurs. It is not limited to. As in the case described in the first embodiment, the period c of supplying the high-frequency power is 3 at maximum when the pressure is 20 mTorr.
When the pressure is about 10 minutes and the pressure is 10 mTorr, the maximum setting is about 1 minute. However, when the supplied power becomes high, the time until the occurrence of abnormal discharge becomes short. In this case, therefore, it is necessary to shorten the time of the supply period c.

Further, in the present embodiment, the power is set to 250 W and the time is set to 2 msec in the period d in which the high frequency power is periodically lowered, but these are not limited to the numerical values. In the period d in which the supply of the high frequency power is periodically reduced, it is sufficient that the charging occurring within the time of the period c in which the normal power is supplied is relaxed, and may be higher than 250 W and shorter than 2 msec. However, if the electric power in the period d becomes high, it takes time to alleviate the charging, and if it becomes too high, the electric power is charged instead of alleviating the charging, and abnormal discharge occurs. Therefore, it is desirable to set the electric power to about the lowest electric power that can substantially maintain the discharge. In the present embodiment, the first
Since the power supply is not completely stopped as in the embodiment,
It is desirable to set the time of the period d in which the supply power is periodically decreased to be longer than that in the case where the power supply is completely stopped.

Here, if the power in the period c for supplying the normal high frequency power is increased or the time is lengthened, the period d in which the power supply required to reduce the charging is lowered also becomes long. . Further, as described above, in the charging relaxation period d, the time required for charging relaxation also changes depending on the power. Therefore, it is necessary to adjust the time of the period c for supplying the normal high-frequency power and the power and time of the period d for reducing the supplied power. Further, as described above, depending on the conditions of the device and the surface of the target and the process conditions, abnormal discharge is likely to occur and may occur in a few seconds. Therefore, it is desirable that the time of the period c for supplying the normal high-frequency power is set substantially in the msec order as in the present embodiment, and at the longest in the 100 msec order.

In the above embodiment, Sn is added to In ₂ O _3.
An example of forming an ITO transparent conductive film by a high-frequency magnetron sputtering method using a disk-shaped target having a diameter of 8 inches, which is a sintered body (density 95%) to which O ₂ is added by 10 wt% is described. The shape, size, etc. are not limited to those of the above embodiment. Even for targets for forming the same ITO transparent conductive film, the amount of SnO ₂ added is different, or the shape is rectangular or elliptical, that is not a sintered body, only pressed, and the density is different. Even according to the invention I
A method for manufacturing a TO transparent conductive film can be applied. Further, the positional relationship between the target and the substrate is not limited to this embodiment, and for example, the method for producing an ITO transparent conductive film of the present invention is applied to an in-line film forming method in which a film is formed while moving in front of the target. it can. Further, also in a film forming method in which a single or a plurality of magnets arranged on the back surface of the target are oscillated or eccentrically rotated and the entire surface of the target is sputtered, the method for producing an ITO transparent conductive film of the present invention Can be applied.

The frequency of the high frequency power in the above embodiment is
Although it is generally used at 13.56 MHz, the frequency is not limited to this value, and the method for producing an ITO transparent conductive film of the present invention can be applied to high frequencies of other frequencies. For example, although the abnormal discharge is generated by the conventional method even at the frequency of 40.68 MHz, by applying the method of the present invention, the abnormal discharge is prevented and a stable ITO transparent conductive film can be manufactured.

In the above embodiment, Ar gas or Ar
Although the case where the sputtering gas in which He gas is added to the gas is used has been described, the sputtering gas is not limited to this, and the case where another rare gas is used or the case where a reactive gas such as oxygen or nitrogen is added is used. The method for producing an ITO transparent conductive film according to the present invention can be applied.

[0051]

As is apparent from the above description, according to the present invention, I using the high frequency magnetron sputtering method is used.
In the method of manufacturing the TO transparent conductive film, the high frequency power is supplied so that the high frequency power is stopped before abnormal discharge occurs, the charging that occurs during supply is alleviated, and this is repeated periodically. Therefore, stable discharge can be generated without abnormal discharge. This gives good reproducibility I
A TO transparent conductive film can be produced.

Since the duration of the supply stop period for alleviating the charging generated by the high frequency power supply is shorter than the plasma life, stable discharge without abnormal discharge can be maintained even at a pressure lower than the discharge start pressure.

Further, since He gas is added to the sputtering gas, the plasma life is extended, and even when the supply stop time of the high frequency power cannot be set short, a stable discharge with no abnormal discharge is generated at a pressure lower than the discharge start pressure. Discharge can be maintained.

Further, instead of periodically stopping the supply of the high frequency power, the high frequency power is periodically reduced so as to alleviate the charging that has occurred before the reduction, so that a stable discharge without abnormal discharge occurs. Discharge can be generated.
Further, since the discharge does not stop, it is possible to maintain stable discharge without abnormal discharge even at a pressure lower than the discharge start pressure. This also makes it possible to produce an ITO transparent conductive film having good reproducibility.

[Brief description of drawings]

FIG. 1 is a configuration diagram of a high frequency power supply system to a cathode in a high frequency magnetron sputtering apparatus.

FIG. 2 is a waveform diagram of an output voltage of a high frequency power source in a conventional high frequency magnetron sputtering method.

FIG. 3 is a waveform diagram of the output voltage of the high frequency power supply in the method for manufacturing the ITO transparent conductive film according to the first embodiment of the present invention.

FIG. 4 is a waveform diagram of an output voltage of a high frequency power source in a method of manufacturing an ITO transparent conductive film according to another embodiment of the present invention.

[Explanation of symbols]

 11 target 12 back plate 13 impedance matching device 14 high frequency power supply

Claims (4)

[Claims] 1. An indium and tin oxide is used as a target, a magnet is installed on the back surface of the target, and high frequency power is applied to the target in an atmosphere in which only a rare gas or a rare gas and oxygen are introduced as a sputtering gas. The target is supplied and the plasma is converged in the vicinity of the surface of the target.
In a method for producing an ITO transparent conductive film using a high frequency magnetron sputtering method in which a TO transparent conductive film is formed, the supply of the high frequency power is periodically stopped, and the supply time of the high frequency power is longer than the time required to generate an abnormal discharge. A method for producing an ITO transparent conductive film, which is characterized in that it is made short. 2. The method of manufacturing an ITO transparent conductive film according to claim 1, wherein the supply stop time of said high-frequency power is shorter than the life of plasma. 3. The method for producing an ITO transparent conductive film according to claim 2, wherein helium gas is added to the sputtering gas. 4. An indium and tin oxide is used as a target, a magnet is installed on the back surface of the target, and high frequency power is applied to the target in an atmosphere in which only rare gas or rare gas and oxygen is introduced as a sputtering gas. The target is supplied and the plasma is converged in the vicinity of the surface of the target.
A method for producing an ITO transparent conductive film using a high-frequency magnetron sputtering method in which a TO transparent conductive film is formed, characterized in that the high-frequency power is periodically reduced.