JPH11304629A - Leak detecting method for vacuum container, monitoring apparatus for film formation quality and continuous vacuum film formation apparatus - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a leak detecting method in which the consumption amount of helium gas used as a tracer gas can be reduced when the leak of the air to a plurality of vacuum containers in a vacuum film formation apparatus is detected and to obtain a vacuum film formation apparatus which is constituted in such a way that leak places in cathode parts, for sputtering, installed additionally at a plurality of vacuum containers can be specified in a very short time. SOLUTION: In a leak detecting method, a mixed gas of helium and neon is used as a tracer gas when the leak of the air from the outside to a plurality of vacuum containers 1 to 8 in a vacuum film formation apparatus is detected, and the mixing ratio of the helium to the neon in the tracer gas which is blown to the individual vacuum containers 1 to 8 is made different at the respective vacuum containers 1 to 8. In addition, in the vacuum film formation apparatus, the side of the air of cathodes 9 for sputtering is sealed airtightly by airtight containers 10 when the leak of the air from the outside of the cathodes 9, for sputtering, which are installed additionally at the plurality of vacuum containers is detected, and the mixed gas of the helium and the neon is supplied, as the tracer gas, to the airtight containers 10.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a vacuum film forming apparatus (PVD such as sputtering, plasma CVD, low pressure CVD, etc.)
Apparatus for forming a film by using a method, etc.), a process apparatus using a vacuum, a method for detecting a leak in a vacuum vessel used in a measuring apparatus, a film quality monitoring apparatus to which the leak detecting method is applied, and a continuous vacuum film forming apparatus About. In particular, the present invention relates to an efficient technique for specifying a location of an atmospheric leak (vacuum leak) generated in a sputtering cathode mounted on a continuous vacuum film forming apparatus including a plurality of vacuum vessels, and relates to a high-speed vacuum film forming method. The main applications are single-wafer vacuum film forming equipment for phase-change optical disks and transparent electrode films for LCDs (transparent conductive films for glass substrates, plastic substrates, color filters, etc.). The technology relates to technology that can significantly reduce downtime after replacement of a sputtering target when performing in-line film formation using multiple vacuum chambers for film formation. Technology that can greatly contribute to the homogenization of process conditions because it can detect residual gas in a vacuum system when a substrate is loaded by using a meter. Than it is.

[0002]

2. Description of the Related Art As a prior art relating to a method of detecting a leak in a vacuum vessel, for example, Japanese Patent Application Laid-Open No. 8-45856, entitled "Decompression Method and Apparatus": Measurement of oxygen partial pressure and nitrogen partial pressure in a chamber to perform external leak check in a short time, Japanese Patent Laid-Open Publication No. 5-299359, "Film Quality Management Apparatus and Method". Apparatus and method for detecting by means of a partial pressure measuring means and issuing an alarm, JP-A-7-103843, "Vacuum leak detection method and apparatus": Helium as a trace gas is sprayed onto a sealed vacuum vessel by a helium spray gun, Japanese Patent Application Laid-Open No. 9-101229, extracting gas in a vacuum vessel and detecting the presence or absence of trace gas leakage by a helium leak detector. Publication "Method for measuring leaked air amount in vacuum vessel": airtightness of a vacuum vessel containing water vapor is confirmed using a residual gas analyzer without breaking vacuum and without using a lid. No. 240729, “Leakage inspection device”: As a measurement of the leakage amount of a master leak used for the sensitivity configuration of the leakage inspection device, etc., the vacuum chamber is swept to a predetermined vacuum pressure by a vacuum pump, and then a master leak is supplied from a trace gas supply source. , A trace gas is leaked into the vacuum chamber at a constant flow rate for a predetermined time, and a trace gas concentration in the vacuum chamber is measured by a gas sensor (mass spectrometer). Japanese Patent Application Laid-Open No. 6-74855 entitled "Vacuum Leak Detection Method and Apparatus" Etc.

[0003]

In recent years, with the recent advancement of electronic devices, especially information and communication technology, liquid crystal displays (LCD) have been used as peripheral devices for displaying and recording information.
And optical disk devices have begun to be rapidly used, and a vacuum film forming apparatus has been used as an indispensable device for manufacturing these devices. For example, a liquid crystal display uses a transparent electrode substrate, which is formed on a glass or plastic substrate or a substrate on which a color filter is formed by a vacuum film forming apparatus. A transparent conductive film for a transparent electrode is formed on a substrate.
Further, as a transparent conductive film, for example, ITO (Indium Tin)
Oxide) and, if necessary, an apparatus for continuously producing a transparent inorganic thin film for protection on the lower and upper layers of the transparent conductive film at a low cost by a vacuum film forming method, for example, a sputtering method.

[0004] In order to reduce the manufacturing cost in manufacturing these devices, how to process a large amount at once,
One of the major propositions is how to reduce the downtime of the apparatus or how to reduce the cost by synergistic effects of the two. In order to solve this problem, there is an in-line type component in which a plurality of vacuum chambers are connected in series, and a film carrier is continuously or horizontally transported on a substrate carrier on which one or a plurality of substrates to be film-formed are mounted. There is a membrane device. In this in-line type film forming apparatus,
There is a substrate loading chamber (hereinafter referred to as a “load lock chamber”) into which a substrate carrier is loaded. From there, a final substrate unloading chamber is formed while continuously forming a desired thin film without delay through a plurality of vacuum vessels. (Hereinafter, referred to as an unloading chamber) to take out the processed substrate.

On the other hand, in an optical disk apparatus, an optical disk medium (recording medium) as a device for recording is formed by applying a recording material or a reflective material to a thin disk of a 5-inch transparent resin by a vacuum coating method. Taking an example of a phase-change type optical disc, which is one of the rewritable optical discs that have attracted attention in recent years, an optical recording material and a reflective material are formed in multiple layers, and in order to reduce the tact time of the film formation and reduce the manufacturing cost, Leaf processing has become common. In recent years, equipment for manufacturing phase-change optical disk media has a plurality of vacuum containers that take in and out media substrates and vacuum containers equipped with film-forming sputtering cathodes in order to perform high-speed single-wafer processing. In the center of the circumference, there is a substrate transfer mechanism that also serves as a partition for each vacuum container and has arms for holding the media substrate as many as the number of vacuum containers. The method of forming a thin film is increasing.

In each of the above two examples, a so-called high-rate sputtering apparatus for forming a desired thin film at a high speed by using a sputtering cathode mounted on each of a plurality of vacuum vessels is provided. It is necessary to frequently change the thin film material to be used, the so-called target material. Taking a single-wafer sputtering apparatus for manufacturing a phase-change optical disk as an example of the above two examples, a vacuum container (hereinafter, load / unload) that receives a medium substrate in a vacuum and takes it out of the vacuum after a series of film formation. After placing the substrate in a load chamber) and evacuating, a dielectric thin film is formed in each of the following three vacuum containers by RF magnetron sputtering. Subsequently, in the next vacuum container, a thin film of a phase change material, which is an optical recording material, is formed by DC magnetron sputtering, and then a dielectric thin film is formed again in the next vacuum container. In the subsequent two vacuum vessels, a thin film of an aluminum alloy having a function of reflection and other functions is formed by a DC magnetron sputtering method, and finally, the substrate after a series of film forming processes is carried out of the load / unload chamber. .

In the above-described example of the phase change type optical disk manufacturing apparatus, the temperature of the substrate is not excessively increased during the film formation, and the required thin film thickness can be efficiently formed.
Dielectric thin film (for example, ZnS / SiO ₂ composite target material), aluminum alloy thin film (for example, alloy of Al and Cr)
Are continuously formed in three or two vacuum vessels, respectively. Since such a single wafer processing is sputtered at a high speed in each vacuum vessel, one substrate is loaded / loaded.
This is a high-speed processing device that can be processed in a time of 7 seconds or less, at most 10 seconds or less, after being put into the unload chamber and completing a series of film forming processes and being taken out of the load / unload chamber again. As is apparent from this example, in the phase change optical disk manufacturing apparatus, a plurality of sputtering cathodes are simultaneously used to form a film at a high speed, so that the target material mounted on the sputtering cathode is greatly consumed. The actual mass production experienced requires the target material to be changed once every two or three days.

As described above, in a film forming apparatus having a plurality of sputtering cathodes, the sputtering target, which is a film forming material, is frequently changed. Usually, the target is installed on a sputtering cathode, and the sputtering cathode is hermetically sealed in a vacuum vessel via a sealing material such as an O-ring (O-ring). However, in general, when a thin film is formed by sputtering, part of the target material becomes particles (fine powder), which scatters and accumulates in the vacuum vessel, adheres to the hermetic seal portion, and is a factor that hinders hermeticity. This particle generation is remarkable in the body thin film. When airtightness is impaired, even a minute leak often gives a critical defect to the quality of the thin film. There are various causes such as deterioration of sealing materials such as O-rings and deterioration of the welded part of the container in addition to particles as causes of poor airtightness. Unless the cause of the above is eliminated and the normal vacuum state is not immediately restored, the loss due to the downtime of the apparatus increases, and this has a particularly large effect on the apparatus for continuous processing in a single-wafer system.
Of the above two examples, the in-line type manufacturing apparatus for the transparent conductive film for LCD is various, but also in this case, a large number of vacuum vessels are arranged in a line (linear), and Many sputtering cathodes are mounted, and I
Since the TO film and the protective film (for example, SiO ₂ ) are ceramic-based thin films, they generate a lot of particles, and high-speed sputtering is performed in each vacuum vessel, so that targets are frequently exchanged. Similar to the above example of the device.

As symbolized by the above two examples of thin film manufacturing apparatuses, recent vacuum film forming apparatuses manufacture process-sensitive thin films for devices, and a plurality of sputtering cathodes in a plurality of vacuum vessels. To perform a continuous and high-speed film forming process. Therefore, prevention of air leakage from outside to the vacuum vessel (external leak) and detection, identification,
The degree to which repairs contribute to production costs is very large. As a recent trend, plastic (synthetic resin substrate) is often used as a substrate for devices, and it is an essential requirement to control the presence or absence of external leaks and the residual gas in the vacuum vessel when the substrate is loaded in the film formation process It has become. For leaks from the outside of the vacuum container, generally, (1) the pressure rise in the closed container after evacuation is observed, (2) the leak is detected by the generation of bubbles such as soapy water, (3) There are various methods such as detecting a leak by spraying a trace gas (mainly helium gas) from the outside into a closed container, and (4) detecting a partial pressure related to the leak by a mass spectrometer. There is a disadvantage that it takes time to detect the occurrence and specify the location of the occurrence, and the downtime of the apparatus increases.

In order to eliminate the drawbacks of these conventional methods, as a method of detecting an external leak of a vacuum vessel which requires a particularly high degree of operation, for example, as disclosed in Japanese Patent Application Laid-Open No. A method in which a mass spectrometer is connected to the processing chamber to measure an oxygen partial pressure and a nitrogen partial pressure in the processing chamber and to perform an external leak check in a short time.
Japanese Patent Application Laid-Open No. 299359/1990 discloses a device and method for detecting a leak in a vacuum chamber at the time of film deposition by a partial pressure measuring means and issuing an alarm. These methods are methods for detecting the partial pressure of gas (atmosphere) leaking from the outside even while the apparatus is operating, using a mass spectrometer connected to a vacuum vessel, and are effective means for reducing leak detection accuracy and time. However, there are the following disadvantages.

(I) It is applicable to a vacuum film forming apparatus using a single vacuum vessel, particularly a batch type apparatus, but a mass spectrometer is expensive for a vacuum film forming apparatus comprising a plurality of vacuum vessels. Since it is a simple measuring instrument, it is not cost-effective to install it in an individual vacuum vessel for external leak detection. (Ii) Judgment by the residual gas partial pressure inside the vacuum vessel without using trace gas from outside, specifically, in the case of atmospheric leakage, the determination of the partial pressure of oxygen and nitrogen in the vacuum vessel is based on the wall surface of the vacuum vessel. The effect of gas released from the gas or gas generated from internal components such as a processing substrate cannot be removed. Specifically, regarding the mass spectrum, the main peak of the oxygen partial pressure is m / e = 32,
The main peak of nitrogen partial pressure appears at m / e = 28, but not all peaks are derived from oxygen and nitrogen in the atmosphere. Oxygen, hydrogen and carbon remaining in the vacuum vessel, compounds generated therefrom, or gas coming out of the built-in material appear greatly depending on the type of substrate, and m / e =
For example, among m / e = 28 among 32 and 28, hydrocarbon fragment peak (C ₂ H ₄ +) and carbon monoxide (C
Since O +) is a mass number that appears, there is a situation where it cannot be immediately determined as a spectrum derived from nitrogen from an atmospheric leak.
In order to eliminate these effects, it is necessary to minimize the so-called background spectrum, but in a production apparatus, it is practically impossible to perform the above-described treatment in advance, and a means for performing such treatment is required. Is generally not provided in view of necessity.

Although it is convenient to connect the mass spectrometer directly to the vacuum vessel without citing the typical prior art examples shown above, it is necessary to check the vacuum by leak check or residual gas partial pressure measurement. While this is an effective method for both aspects of quality assurance, it can lead to rough and ambiguous detection results. On the other hand, in another method using a mass spectrometer, for example, as disclosed in JP-A-7-103843,
A method of spraying helium as a trace gas onto a sealed vacuum vessel with a helium spray gun to extract the gas in the vacuum vessel and detecting the presence or absence of trace gas with a helium leak detector;
Japanese Patent Application Laid-Open No. Hei 9 (1994) -5, as disclosed in Japanese Unexamined Patent Application Publication No. Hei 9 (1999), discloses a method for checking the airtightness of a vacuum vessel containing water vapor using a residual gas analyzer without breaking vacuum and using a lid.
There are conventional techniques such as Japanese Patent Application Laid-Open No. 240729/1994 and Japanese Patent Application Laid-Open No. 6-74855. The method of detecting an external leak by performing detection using a trace gas with a mass spectrometer or a mass spectrometric helium leak detector requires a lot of time and consumption of expensive helium gas to identify the leak point, and also requires a vacuum vessel. The quality of the internal vacuum cannot be judged. Further, in an apparatus in which a plurality of vacuum vessels are operated continuously, it takes a great deal of trouble to change the connection of the detection apparatus in order to check for an external leak, and the operation rate is extremely reduced.

Next, the drawbacks of the prior art and the problems to be solved by the invention described in each claim will be described.

1. Conventionally, detection of atmospheric leakage (external leak) of a vacuum vessel is based on checking (detection) individually corresponding to each vacuum vessel, and helium gas is sprayed as a trace gas to each vacuum vessel to form a vacuum vessel. Trace gas leaking into the vessel was detected. In addition, in the detection of atmospheric leakage of a vacuum film forming apparatus composed of a plurality of vacuum vessels, it takes time to consume a large amount of expensive helium gas or to change a mass spectrometer or helium leak detector as a detecting device. It was very large, causing a large decrease in the operation of the entire apparatus.

The invention described in claim 1 has been made in view of the above circumstances, and an object (object) of the present invention is to provide a leak detection method capable of reducing the amount of helium gas used as a trace gas. I do.

2. Conventionally, when measuring atmospheric pressure by measuring partial pressure with a mass spectrometer, helium gas was used as a trace gas, but in this method, a vacuum component composed of a plurality of vacuum vessels was used. In a membrane device, a large amount of helium gas is consumed each time, and each vacuum vessel is sequentially and individually leak-detected, or the vacuum of all the vacuum vessels is communicated, and there is a possibility that a leak may occur in the entire vacuum system. Since the same trace gas is sequentially blown to a certain part to check for a leak sequentially, it took time to specify a leak occurrence part. This is because helium alone is a very light noble gas having a mass number of 4 and easily diffuses in a vacuum. If helium is detected from all vacuum vessels by leakage, It is not possible to determine whether the helium is helium or not, and it is necessary to wait for the start of the next detection due to the remaining helium, resulting in a time loss.

The invention according to claim 2 has been made in view of the above circumstances, and it is possible to inspect each vacuum vessel of a vacuum film forming apparatus at the same time, so that the location of an atmospheric leak from the outside can be specified very quickly. It is an object (object) to provide a leak detection method.

3. Conventionally, when measuring atmospheric pressure by measuring a partial pressure with a mass spectrometer, helium gas was generally used as a trace gas, but in this method, a vacuum component composed of a plurality of vacuum vessels was used. In a membrane device, a large amount of helium gas is consumed each time, and each vacuum vessel is sequentially and individually leak-detected, or the vacuum of all the vacuum vessels is communicated, and there is a possibility that a leak may occur in the entire vacuum system. It was necessary to sequentially spray trace gas to a certain site to check for leaks sequentially, and it took an enormous amount of time, and it was practically impossible to detect air leaks during operation of the apparatus.
For this reason, the downtime of the apparatus is simply multiplied by the number of vacuum vessels, resulting in an extremely low operation rate.

The invention according to claim 3 has been made in view of the above circumstances, and provides a leak detection method capable of detecting an atmospheric leak even while the apparatus is operating without consuming a large amount of helium gas. Providing is an issue (purpose).

4. A mass spectrometer often used in a monitor system of a production apparatus using a vacuum vessel ionizes gas molecules in a gas in the vacuum vessel by an electron impact method and separates them as a mass / charge ratio (m / e) of ions (mass). Separation) is common. In the ionization by the electron impact method, even if the ionization voltage is the same, the ionization probabilities of the gas species to be ionized are different. For example, in helium and neon, the spectral sensitivity of the mass spectrometer appears differently. Therefore, the obtained spectrum intensity ratio for each gas type does not directly reflect the abundance of each gas type in vacuum. When a mixed gas is used as a trace gas, for example, helium and neon have different sizes and masses of gas molecules, so it is necessary to check in advance the difference in the amount of gas entering from a leak location in a vacuum vessel. For this purpose, the sensitivity of the mass spectrometer for the gas type must be determined, and the specific sensitivity to the reference gas type must be determined to correct the spectrum intensity before it is reflected as a true physical quantity in the vacuum vessel. However, in the prior art, even in a method of detecting an external leak by detecting a trace gas or measuring a residual gas partial pressure, it is necessary to rely on a qualitative means that does not consider such calibration.

The invention described in claim 4 has been made in view of the above circumstances, and when the mixed gas of helium and neon is used as the trace gas, the existence ratio of helium and neon in the vacuum vessel is accurately grasped. It is an object (object) to provide a leak detection method that can specify a location of an external leak in a very short time based on the data of the abundance ratio.

5. Eliminating atmospheric leakage from a vacuum vessel is an essential requirement for a process device utilizing a vacuum in order to ensure process stability. Japanese Patent Application Laid-Open No. 8-4585 for detecting atmospheric leakage by measuring partial pressure of residual gas using a mass spectrometer
Although the prior art represented by Japanese Patent Publication No. 6 is an effective method mainly for detecting an external leak, the degree of vacuum (pressure) of a vacuum vessel to be subjected to a leak test is limited, and the target vacuum is It is merely a means for detecting the partial pressure under a relatively low pressure where the residual gas and the external intrusion gas exist in the container in real time to determine the presence or absence of the external leak. However, since the degree of vacuum pressure differs depending on the vacuum film formation process,
Conventional processes cannot respond to the vacuum pressure inherent in the process. Since the size of the vacuum pump for evacuating the vacuum space in which the mass spectrometer is installed is also limited, if the vacuum pressure of the vacuum vessel for which external leakage is to be checked is high, the mass spectrometer should be adjusted accordingly. It is necessary to limit the amount of gas flowing into the side. In addition, when filling a process gas when forming a film in a vacuum container, confirming the quality of a residual gas remaining in the vacuum container, that is, a so-called back background, ensures the quality of a vacuum-formed thin film. However, at present, no such basic considerations have been made.

The invention described in claim 5 has been made in view of the above circumstances, and is not limited to the degree of vacuum (pressure) of the vacuum container to be subjected to a leak test, and is not limited to the vacuum container when checking an external leak. When the vacuum pressure is high, the partial pressure measurement can be performed by limiting the amount of gas flowing into the mass spectrometer side accordingly, and the quality of the residual gas before performing the film forming process in a vacuum vessel, so-called It is an object (object) to provide a film formation quality monitoring device capable of measuring a background and stabilizing film formation quality.

6. An in-line vacuum film forming apparatus that uses a plurality of vacuum vessels to continuously form a desired thin film without releasing vacuum, a single-wafer type vacuum film forming apparatus that continuously processes an object to be processed, etc. Of the continuous vacuum film forming apparatuses described above, a sputtering apparatus having high productivity by high-speed film forming uses a plurality of sputtering cathodes. in this case,
Since the target installed on the sputtering cathode is greatly consumed, it is necessary to frequently replace the target,
Each time, the vacuum vessel is opened to the atmosphere. In addition, particles are often generated during the formation of the thin film, which often causes external leakage of the vacuum vessel. Conventionally, in order to check for external leaks, a method of detecting external leaks by means of partial pressures of oxygen and nitrogen using a mass spectrometer (Japanese Patent Laid-Open No. 8-45856) or a method of spraying a trace gas onto a vacuum vessel to discharge the trace gas is used. Detection method (Japanese Patent Laid-Open No. 7-103843)
There is. However, the conventional method has the disadvantage that connecting the mass spectrometer to all of the plurality of vacuum vessels requires too much equipment cost and consumes a large amount of expensive helium gas used as a trace gas. Further, in such a continuous vacuum film forming apparatus, a site where external leakage may occur, such as a sputtering cathode that is opened to the atmosphere for frequent replacement of a target, is estimated in advance. It is necessary to reduce the consumption of expensive helium gas by squeezing, but this has been overlooked.

The invention described in claim 6 has been made in view of the above circumstances, and it is possible to specify an external leak portion of a sputtering cathode portion provided in a plurality of vacuum vessels in a very short time, and to perform individual vacuum It is an object (object) to provide a continuous vacuum film forming apparatus having a configuration in which it is not necessary to install a detecting device such as a mass spectrometer for each container or to connect and replace the detecting device for each vacuum container.

7. Among continuous vacuum film forming apparatuses such as an in-line type vacuum film forming apparatus and a single-wafer type vacuum film forming apparatus for continuously processing an object to be processed, a sputtering apparatus having high productivity by high-speed film forming is used for a plurality of sputtering. The cathode is used. In such a sputtering apparatus, in order to check an external leak, conventionally, a method of detecting an external leak by a partial pressure of oxygen and nitrogen using a mass spectrometer or a method of spraying a trace gas to a vacuum vessel to detect a trace gas is used. There was a way. However, connecting the mass spectrometer to all of the plurality of vacuum vessels as in the conventional method has disadvantages in that the cost of the apparatus is too high and that expensive helium gas used as a trace gas is consumed in large quantities. In a continuous vacuum film forming apparatus with a large number of vacuum vessels as described above, careful inspection of all possible locations where external leakage can occur using the same method will result in extremely low continuous operation in a continuous and high-speed apparatus. There was a problem.

The invention described in claim 7 has been made in view of the above circumstances, and it is possible to easily detect an external leak of the entire apparatus by connecting only one mass spectrometer.
To provide a continuous vacuum film forming apparatus capable of efficiently detecting leaks while the apparatus is in operation, without the need to interrupt the film forming operation of the apparatus and change the mass spectrometer as in the prior art. Is the task (purpose).

8. Among continuous vacuum film forming apparatuses such as an in-line type vacuum film forming apparatus and a single-wafer type vacuum film forming apparatus for continuously processing an object to be processed, a sputtering apparatus having high productivity by high-speed film forming is used for a plurality of sputtering. The cathode is used. In such a sputtering apparatus, since the sputtering cathode is often opened to the atmosphere, in order to check for an external leak that can occur at a considerable frequency, the external leak is conventionally detected by a partial pressure of oxygen and nitrogen using a mass spectrometer. There has been a method of detecting or a method of detecting a trace gas by spraying a trace gas onto a vacuum container. However, conventionally, the external leak detection method and the residual gas analysis for checking the quality of film formation are often performed as separate tasks. In other words, when the degree of vacuum is low due to the occurrence of external leakage, helium gas is sprayed from the outside of the vacuum vessel using a mass spectrometric helium leak detector to carefully search for leaks, and if there is a problem with the deposition quality separately, It has been common practice to monitor the background remaining in the vacuum vessel with a mass spectrometer directly connected to the vacuum vessel. For this reason, a double capital investment for separately preparing an external leak detection device and a background measurement device has been common.

The invention described in claim 8 has been made in view of the above circumstances, and eliminates the need for a double capital investment of separately preparing an external leak detecting device and a background measuring device, and reducing external leaks. In some cases, the sputtering cathode site where it is occurring can be immediately identified, and when there is no external leakage, background monitoring during the deposition process can be performed in-line (in-process). It is an object (object) to provide a device.

9. Among continuous vacuum film forming apparatuses such as an in-line type vacuum film forming apparatus and a single-wafer type vacuum film forming apparatus for continuously processing an object to be processed, a sputtering apparatus having high productivity by high-speed film forming is used for a plurality of sputtering. The cathode is used. In such a sputtering apparatus, since the sputtering cathode is often opened to the atmosphere, in order to check for an external leak that can occur at a considerable frequency, the external leak is conventionally detected by a partial pressure of oxygen and nitrogen using a mass spectrometer. There has been a method of detecting or a method of detecting a trace gas by spraying a trace gas onto a vacuum container. However, connecting the mass spectrometers to a plurality of vacuum vessels, as in the conventional method, has the drawback that the cost of the apparatus is too high and the expensive helium gas used as the trace gas is consumed in large quantities. In the above production equipment with a large number of vacuum vessels, careful inspection of all locations of multiple vacuum vessels that can cause external leaks using the same method requires extremely low continuous operation at continuous and high-speed equipment. There was a problem of doing. In addition, when there are a plurality of relatively large external leaks, the helium gas, which is a trace gas, is leaked and remains for a considerable time, which may be an obstacle when searching for another external leak. Was one of the causes of this. Also,
In such a continuous vacuum film forming apparatus as described above, a portion where external leakage may occur is estimated in advance, such as a sputtering cathode that is opened to the atmosphere for frequent replacement of a target. It is necessary to narrow down the consumption of expensive helium gas, but this has been overlooked.

The invention according to claim 9 has been made in view of the above circumstances, and can reduce the consumption of expensive helium gas, and can also immediately identify a site where an external leak has occurred, To provide a continuous vacuum film forming apparatus capable of detecting external leaks even while the film forming apparatus is operating, and realizing both improvement in operation rate and yield at the same time, since it is not necessary to change a detecting apparatus for each vacuum vessel and to reduce capital investment. Is the task (purpose).

10. Such as in-line vacuum film forming equipment for manufacturing transparent conductive film substrates using sputtering cathodes with high productivity by high-speed film forming, and single-wafer type vacuum film forming equipment for continuously processing phase-change optical disc substrates in single wafers. In a continuous vacuum film forming apparatus, a tact time for forming a vacuum film on one substrate is several seconds to several tens of seconds, and the apparatus is continuously operated. The replacement of the target material is frequent, and the occurrence of external leakage directly leads to poor quality of the substrate to be processed. An external leak may occur immediately after the target replacement, or an external leak may suddenly occur at some point immediately after the replacement even if there is no abnormality. Therefore, unless multiple vacuum vessels are checked for external leaks at the same time and the location where they occur is not immediately identified, the processed substrate will continue to be processed with poor quality thereafter, resulting in large losses. There were many. In the conventional technology, the vacuum pressure is checked only for the target vacuum vessel immediately after the target is replaced, and the mass spectrometer is often used to determine the partial pressure of oxygen and nitrogen. Was impossible to capture.

The invention according to claim 10 has been made in view of the above circumstances, and it is possible to specify a location where an external leak occurs without stopping the operation of a continuous vacuum film forming apparatus for performing a film forming process at a high speed. The object of the present invention is to provide a continuous vacuum film forming apparatus capable of preventing troubles in which a substrate that has been processed is processed with poor quality thereafter, resulting in a large loss. (Purpose).

[0034]

According to a first aspect of the present invention, there is provided a vacuum film forming apparatus comprising a plurality of vacuum chambers, wherein the vacuum chamber detects a leak in the vacuum chamber. A detection method, characterized in that a trace gas is used when detecting atmospheric leakage from the outside to each vacuum vessel, and a mixed gas of helium (He) and neon (Ne) is used as the trace gas. It is what it was.

According to a second aspect of the present invention, there is provided a leak detecting method for detecting a leak in the vacuum vessel in a vacuum film forming apparatus comprising a plurality of vacuum vessels, wherein the method comprises the steps of: In detecting a leak, a mixing ratio of helium and neon of a trace gas blown to each vacuum vessel is different for each vacuum vessel.

According to a third aspect of the present invention, there is provided a leak detecting method for detecting a leak in the vacuum vessel in a vacuum film forming apparatus comprising a plurality of vacuum vessels, wherein the leak detecting method detects an atmospheric leak from outside the vacuum vessel. In doing so, apart from the individual vacuum vessels in which the objects to be processed are loaded or unloaded or vacuum deposited,
It has a common vacuum space communicating with each vacuum vessel, and detects a partial pressure of the atmosphere and trace gas leaked from each vacuum vessel into this vacuum space by a mass spectrometer.

According to a fourth aspect of the present invention, in the method for detecting a leakage of a vacuum vessel according to the third aspect, helium and neon are mixed in a molar ratio before detecting the partial pressure of the trace gas leaking into the vacuum space. Equal amount included (mixing ratio is 1: 1)
The trace gas is flowed into the vacuum space, the sensitivity coefficient of the mass spectrometer for the helium and neon gas species is set in advance, the sensitivity of the partial pressure of the mass spectrum is calibrated, and then the partial pressure of the trace gas is detected. It is what it was.

According to a fifth aspect of the present invention, in a vacuum film forming apparatus comprising a plurality of vacuum vessels, a leak in the vacuum vessel is detected by using the leak detecting method according to the third or fourth aspect, and the film is formed. A film quality monitoring device for monitoring quality, wherein a mass spectrometer is used to detect a residual gas in a common vacuum space communicating with each vacuum vessel, an atmosphere leaking into the vacuum space, and a trace gas, and The mass spectrometer includes both a gas sampling path having a pore (orifice) for taking in a part of the gas in the vacuum vessel while reducing the pressure, and a gas sampling path having no pore. The vacuum space where the gauge is installed is provided with a differential pumping device.

According to a sixth aspect of the present invention, there is provided a continuous vacuum film forming apparatus comprising a plurality of vacuum vessels, wherein when detecting atmospheric leakage from the outside of a sputtering cathode attached to the vacuum vessel. The sputtering cathode is sealed on the atmosphere side with a sealed container, and a trace gas for detecting air leakage is supplied to the sealed container, and the trace gas is a mixed gas of helium and neon. is there.

According to a seventh aspect of the present invention, there is provided a continuous vacuum film forming apparatus comprising a plurality of vacuum vessels, wherein when detecting atmospheric leakage from the outside of a sputtering cathode attached to the vacuum vessel. In addition to the individual vacuum vessels in which the workpiece is loaded or unloaded or subjected to vacuum film formation, a common vacuum space communicating with each vacuum vessel is provided, and the atmosphere leaking from each vacuum vessel to this vacuum space and It is characterized in that the partial pressure of the trace gas is detected by a mass spectrometer.

An eighth aspect of the present invention is a continuous vacuum film forming apparatus comprising a plurality of vacuum containers, wherein each of the vacuum containers into which an object to be processed is loaded or unloaded or subjected to a vacuum film forming process. The apparatus according to claim 5, further comprising a common vacuum space communicating with each of the vacuum vessels, and detecting a residual gas partial pressure in the vacuum space, an atmosphere leaking into the vacuum space, and a trace gas. A film quality monitoring device is provided.

According to a ninth aspect of the present invention, there is provided a continuous vacuum film forming apparatus comprising a plurality of vacuum vessels, wherein when detecting atmospheric leakage from the outside of a sputtering cathode attached to the vacuum vessel. In addition to the individual vacuum vessels in which the workpiece is loaded or unloaded or subjected to vacuum film formation, a common vacuum space communicating with each vacuum vessel is provided, and the atmosphere leaking from each vacuum vessel to this vacuum space and The partial pressure of the trace gas is detected by a mass spectrometer, and the mixing ratio of helium and neon of the trace gas sprayed on each vacuum vessel varies from vacuum vessel to vacuum vessel. It is characterized by specifying.

According to a tenth aspect of the present invention, there is provided a continuous vacuum film forming apparatus comprising a plurality of vacuum vessels, wherein when detecting atmospheric leakage from the outside of a sputtering cathode attached to the vacuum vessel. In addition to the individual vacuum vessel in which the object is loaded or unloaded or vacuum-deposited,
It has a common vacuum space that communicates with each vacuum vessel, detects the atmospheric pressure and the partial pressure of the trace gas leaked from each vacuum vessel into this vacuum space by a mass spectrometer, and detects the trace gas helium blown to each vacuum vessel. Since the mixing ratio of neon is different for each vacuum vessel, the sputtering cathode that has leaked to the atmosphere can be immediately identified, and the cathode for sputtering that has been detected based on the measurement results of the mass spectrometer can be identified. A monitoring device for identifying and issuing an alarm is provided.

[0044]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, embodiments of the present invention will be described in detail based on illustrated embodiments.

[Embodiment 1] FIG. 1 is a view showing one embodiment of the present invention, which is a continuous vacuum film forming apparatus comprising a plurality of vacuum vessels and continuously forming a film on a substrate to be processed. It is a schematic block diagram. Hereinafter, an example in which the continuous vacuum film forming apparatus having the configuration shown in FIG. 1 is applied to film formation on a phase change optical disk media substrate, and an embodiment of a method for detecting a leak in a vacuum container of the vacuum film forming apparatus will be described.

FIG. 1 shows a continuous vacuum film forming apparatus in which eight vacuum vessels 1 to 8 of ch1 to ch8 are connected in a circular shape to perform single-wafer processing of a substrate to be processed. The vacuum vessel 1 of ch1 is a robot. And a load / unload chamber for loading / unloading a substrate from / to a substrate supply / discharge mechanism into / from a film forming apparatus. That is,
The vacuum vessel 1 is a vacuum vessel that performs a so-called load lock, and performs a vacuum evacuation operation with a valve 15 and a rotary pump 14. The resin substrate (polycarbonate is generally used in the case of a phase-change optical disk media substrate) placed in the vacuum container 1 of ch1 is an extensible substrate transfer rotation that can freely come and go with each vacuum container installed in the substrate transfer mechanism. It is received by the arm 13, and is rotated by ８ in the direction of the arrow in the drawing in the substrate transfer chamber 12 and transferred to the next vacuum vessel 2, ch 2. Sealed. The substrate transfer chamber 12 is a turbo molecular pump 2
At 1, a high vacuum state is always maintained, and the gas released from the substrate during the transfer of the substrate is evacuated.

The vacuum vessel 2 of ch2 is evacuated to a high vacuum in advance by a turbo molecular pump and stands by so that sputtering can be performed in an argon gas atmosphere. In the vacuum vessel 2, a dielectric thin film is formed by RF magnetron sputtering. Therefore in the sputtering cathode 9 of the vacuum vessel 2, for example target material ZnS · SiO ₂ is placed. Here, a film is formed to a predetermined film thickness within 3 seconds at a film forming speed of about 110 ° / sec, and the same dielectric thin film is RF magnetron-sputtered in the vacuum chambers 3 and 4 of ch3 and ch4 in the same operation. Then, a dielectric thin film is formed in a total thickness of about 1100 ° in the vacuum vessels 2 to 4 from ch2 to ch4.

Subsequently, the substrate is transferred to the next vacuum vessel 5 of ch5, and a thin film of a phase change material (eg, Ge, Sb, T) is formed as an optical recording layer by DC magnetron sputtering.
e) (using an alloy target containing e). In this case, since the film forming speed is 55 ° / sec, the film forming time is less than 4 seconds. In the next vacuum container 6 of ch6,
Similarly to the vacuum container 2 of ch2, a dielectric thin film (for example, Zn
(S.SiO ₂ ) is deposited at 380 ° by RF magnetron sputtering. Subsequently, in vacuum chambers 7 and 8 of ch7 and ch8, a thin film of an aluminum alloy (for example, an alloy of Al and Cr) serving as a reflection layer and a heat radiation layer is formed in a total thickness of 1600 °. In the vacuum chambers 7 and 8 of ch7 and ch8, a thin film is formed by a DC magnetron sputtering method, and the film forming speed is 230 ° / sec. Therefore, the film forming time in each vacuum vessel is about 3.5 seconds. .

In FIG. 1, the cathodes for sputtering provided in the vacuum chambers 2 to 8 for film formation are commonly denoted by the reference numeral 9, and the closed vessel 10 and the gas inlet 11 provided for the cathodes 9 for sputtering are the same. Therefore, the names are the same. On the other hand, the vacuum vessels 2 to 8 for film formation are individually evacuated to a high vacuum by a turbo molecular pump, and in FIG.
Of the vacuum vessel 8 of FIG. Here, reference numeral 17 denotes a turbo molecular pump for ch8, and a mechanical booster pump 19
Is evacuated by the rotary pump 20. Incidentally, the mechanical booster pump 19 and the rotary pump 20 are c
This is a back (back exhaust) exhaust system commonly used for the vacuum vessels 2 to 8 of h2 to ch8 and the substrate transfer chamber 12. Reference numerals 23, 24, 25, etc. denote turbo molecular pump exhaust systems, which have the same structure as the turbo molecular pump 17 and the valve 18 connected to the vacuum container 8 of ch8. 7 and the back (for back exhaust) exhaust system 1
It is simply shown that the connection is made between 9, 20. In addition, illustration of a nitrogen gas for leakage, an argon gas introduction system for sputtering, a vacuum gauge for measuring a degree of vacuum, and the like connected to each vacuum vessel are omitted.

In such a continuous type film forming apparatus, targets are frequently exchanged. In the above-described apparatus, RF magnetron sputtering is performed at about 5 kW, DC magnetron sputtering is performed at about 6 kW at the maximum (a thin film of the phase change material is 2 kW).
(less than kW), the target is quickly consumed because of the large number of substrates processed, and according to the present inventors' experience, the work of replacing the film-forming target occurs almost every day. Was. For this reason, the downtime of the apparatus due to the work at the time of replacement and the trouble caused by the replacement has been a major cause of the decrease in the operation rate. Most of this trouble is air leakage (external leakage) to the vacuum vessel. However, since an external leak is generated at an unexpected location when the device has been used for many years, specifying the location of the external leak has been a major issue.

In order to efficiently identify this external leak, the present inventors set up a closed vessel 10 on the atmospheric side of all the sputtering cathodes 9 and provided therewith a trace gas for external leak detection (referred to as a probe gas). (In some cases). Here, FIG. 3 shows a configuration example of the sputtering cathode 9 and the sealed container 10. FIG. 3 is a cross-sectional view of a main part showing an outline of a magnetron type sputtering cathode used in each of the above-mentioned film forming vacuum vessels.
4 is a target material, 208 is the same closed container as 10 in FIG. 1, and 209 is the same gas inlet as 11 in FIG. In FIG. 3, the cooling water system (the cooling water introduction pipe 206,
A sputtering cathode body 202 containing a cooling water 207 and a magnet 210 is installed on a vacuum vessel wall 201 via an insulator 212. Target material 4
Is bonded to a copper backing plate 203,
This is attached to the sputtering cathode body 202 and is directly water-cooled. Reference numeral 205 denotes a copper backing plate 203, a cathode main body 202, a closed container 2
08 is a necessary sealing portion, and is usually sealed with an O-ring. 211 is an earth shield plate. The RF or DC voltage supply electrode to the sputtering cathode body 202 is not shown in FIG.

As described above, the sputtering cathode body 202 is sealed by the closed vessel 208 (10 in FIG. 1), and the gas inlet 209 (11 in FIG. 1) is supplied with helium (He) gas and / or helium and neon (Ne). Is mixed at a predetermined pressure. Although not shown in FIG. 3, the closed vessel 208 is provided with a spring-type valve. When the inside of the closed vessel 208 exceeds the atmospheric pressure, the pressure is reduced to the atmospheric pressure. The gas introduced into the gas inlet 209 in FIG. 3 has a form supplied from a gas introduction system as shown in FIG. That is, the gas introduction system shown in FIG.
It is composed of a container of helium (He) gas alone and a mixed gas container in which helium gas and neon (He + Ne) are mixed at an arbitrary mixing ratio. Each gas container has a pressure reducing valve (not shown). . Further, each container is provided with a shutoff pneumatic drive valve (may be an electromagnetic valve).

Returning to the continuous vacuum film forming apparatus shown in FIG. 1, the substrate transfer chamber 12 has a rotary pump 14 and a valve 1.
5 and the valve 16, the gas is evacuated to a high vacuum by the turbo-molecular pump 21 and is kept at 10 to ⁵ Torr even during the transfer of the substrate.
The table is held in vacuum. Reference numeral 22 designates the back of the turbo molecular pump 21 as a mechanical booster pump 19
And a valve for exhausting by the rotary pump 20.

On the other hand, the substrate transfer chamber 12 is a common vacuum space when the substrate transfer rotary arm 13 does not seal each vacuum vessel, that is, when it is separated from each vacuum vessel. An orifice (pore) tube 26 is provided in the substrate transfer chamber 12.
A mass spectrometer analysis unit (referred to as an analysis tube) 30 is connected via a gas introduction pipe composed of the analysis tube and valves 27 and 28, and 29 is a vacuum chamber (manifold or envelope) for accommodating the analysis tube 30. Called). The manifold 29 is provided with a differential exhaust device 31 using a turbo molecular pump as a main exhaust pump. Also, 3
Reference numeral 2 denotes a mass spectrometer processing device that controls the mass spectrometer and performs data processing. The mass spectrometer is preferably a quadrupole mass spectrometer which is preferably small in size, has a high mass sweeping speed and high detection sensitivity. Actually, a quadrupole mass spectrometer MSQ-150A manufactured by Japan Vacuum Engineering Co., Ltd. was used.

In the present invention, the operation of replacing the sputtering target in the continuous vacuum film forming apparatus having the structure shown in FIG.
In order to improve the downtime of the equipment due to troubles due to replacement, external leak (atmospheric leak) is detected by the following procedure, and if no external leak occurs, the back of the substrate transfer chamber 12 is checked using a mass spectrometer. The ground gas monitor was used to stabilize film formation quality.

<< Procedure 1 >>: Sensitivity calibration of trace gas to mass spectrometer. The sensitivity of the used mass spectrometer analysis tube 30 to the trace gas is set aside by using the sensitivity calibration gas introduction system indicated by reference numeral 34 in FIG. This is because the ionization efficiencies (ionization efficiencies) of helium and neon are different even for the same rare gas. Even if the rare gases mixed at the same mixing ratio are ionized under the same ionization condition, each rare gas can be obtained. This is because the sum of the current values of the mass spectrum is not the same. Actually, helium (He), neon (Ne), argon (Ar), krypton (Kr), xenon (Xe)
A mixed gas in which the rare gases of the species were mixed in an equimolar ratio (equal amounts of 20%) was analyzed by a mass spectrometer. Since the accompanying peak of each of the rare gases is smaller than the main peak, it is ignored, and the main peak is compared with the peak value represented by the ion current value. Under the same conditions, nitrogen gas and helium, or nitrogen gas and neon gas were analyzed in equal amounts, and analyzed.
The nitrogen gas (N
_{2 +; m / e = 28} ) 1.00 (reference) and the when graphed relative sensitivity to that illustrated in Figure 5 is obtained (mass number ratio of the mass / charge ions of gas molecules (m / E)). In this example, when the nitrogen gas (m / e = 28) is 1.00, the ionization efficiency is helium (m / e = 28).
4) is 0.19, and neon (m / e = 20) is 0.19.
29. This value is a specific sensitivity coefficient based on nitrogen. Helium gas is about 1.5 times larger than neon gas.
Double ionization is difficult. For these rare gases, a specific sensitivity coefficient under certain measurement conditions is taken in advance, and data is input to a memory in the mass spectrometer processing device 32 for controlling and data processing of the mass spectrometer in FIG. .

<< Procedure 2 >>: Assignment of trace gas to each vacuum vessel. Helium gas and a helium / neon mixed gas are supplied from the gas inlet 11 (209 in FIG. 3) connected to the closed vessel 10 (208 in FIG. 3) outside the sputtering cathode 9 of each vacuum vessel. Gas mixing ratios were assigned as follows. ch (n): He: Ne = 1: n (n = 1 to
8) In this case, helium (m / e = 4) has a specific sensitivity coefficient γ (H
e) = 0.19, and the specific sensitivity coefficient γ (Ne) = 0.29 for neon (m / e = 20). Thus, for example, He:
When the partial pressure of the mixed gas of Ne = 1: 2 is measured, FIG.
As shown in (a), when the ion current value of the obtained partial pressure peak is divided by the specific sensitivity coefficient, a normalized (converted to nitrogen) partial pressure peak value is obtained.

That is, the normalized partial pressure peak value I
[A] is a partial pressure value obtained by the measurement as i [A].
I = i / a γ, I (He) = 1.1 × 10 ~ 12 /0.19=5.7×10~ 12 I (Ne) = 3.2 × 10 ~ 12 /0.29=1 1 × 10 to ¹¹ . Therefore, I (Ne) / I (He) = 1.93. Similarly, in a mixed gas of He: Ne = 1: 4,
FIG from 6 (b), I (He ) = 1.2 × 10 ~ 12 /0.19=6.3×10~ 12 I (Ne) = 7.4 × 10 ~ 12 /0.29=2. a 55 × 10 ~ ^11. Therefore, I (Ne) / I (He) = 4.05.

In the above-described embodiment, measurement under a certain ionization condition is determined, and the obtained partial pressure value is calibrated to estimate the mixing ratio of the original mixed gas. Table 1
The data processing method is determined in advance as shown in FIG. That is, data processing as shown in Table 1 below is performed by the mass spectrometer processing device 32 of FIG. 1, and the mixing ratio is specified based on the processing result.

[0060]

[Table 1]

<< Procedure 3 >>: External leak inspection (1). The gas introduction system valve M shown in FIG. 4 is opened by replacing the sputtering cathode target material with the apparatus shown in FIG. 1, and a helium / neon mixed gas having a mixing ratio corresponding to the vacuum vessel is supplied to the vacuum vessel. Helium gas is supplied to the other (non-replaced) sputtering cathodes by opening the valve S of the gas introduction system shown in FIG. The mass spectrometer (the mass spectrometer analysis tube 30, the mass spectrometer processing device 3) connected to the substrate transfer chamber 12 of FIG.
Check the mass spectrum of helium and neon in 2).
At this time, the substrate transfer rotary arm 13 that can freely contact (separate and expand) with each vacuum vessel keeps each vacuum vessel unsealed. The pressure in the substrate transfer chamber 12 is 5.0 × 1
When the pressure is 0 to ⁵ Torr or less, the valve 28 shown in FIG. 1 is opened, and the gas to be inspected is directly introduced into the mass spectrometer analysis tube 30, but the pressure in the substrate transfer chamber 12 is 5.0 × 1 due to a large external leak.
0 until a pressure of less than ~ ⁵ Torr when not reached, the valve 28
Is closed to limit the amount of gas introduced through the orifice (pore) tube 26 and the valve 27 to improve the vacuum to a pressure that does not hinder the operation of the mass spectrometer. In this example, there is a large leak, and the pressure in the substrate transfer chamber 12 is 4.0 × 10 to ⁴ Torr.
Orifice (pore) tube 2
The gas was introduced with the opening diameter of No. 6 being 0.5 mm.

According to the measurement of the partial pressure, i) when the partial pressure peaks of neon and helium are observed at the same time, there is an external leak in the sputtering cathode whose target has been replaced (specifying the external leak); ii) neon If the partial pressure peak of the target was not observed and only the partial pressure peak of helium was observed, there was no external leakage in the sputtering cathode where the target was replaced, and there was external leakage in other parts where the target was not replaced. It is determined that an error has occurred (the possibility of an external leak other than the target replacement location).

In the case of the above i), the location of the leak occurrence is specified by the ratio of the calibrated peaks of helium and neon, R = I (Ne) / I (He), and the leak is generated by the leak monitor 33 to display the lamp. The location is displayed and an alarm is generated. In addition, the time required for the determination of the above i) and ii) is
It has been 27 seconds since the gas was introduced from the gas introduction system in FIG.

<< Procedure 4 >>: External leak inspection (2). If it is determined as ii) in << Procedure 3 >> described above, the same operation as in << Procedure 3 >> is performed to identify a portion where external leakage has occurred among a plurality of sputtering cathodes whose targets have not been replaced. That is, a helium / neon mixed gas is supplied to the sputtering cathode of interest, and a helium gas is supplied to the other sputtering cathodes, and the procedure of <Step 3> is repeated to specify an external leak location, and a leak monitoring device is provided. Indicated by 33. This series of data collection, data processing, and determination is performed by the mass spectrometer 32. External leaks in the device shown in FIG. 1 could be identified in the manner described above, and the required time was at most 4 minutes.

In the prior art, even if a person skilled in the vacuum technology is lucky, including the setup time for connection of the inspection device, it takes 2 seconds to identify the occurrence of the external leak.
Although the time required, and in some cases, 5 hours or more, is required, the operability of the film forming apparatus has been remarkably reduced. However, the leak detection method of the present invention can find an external leak in a remarkably short time and repair it. The time before the start was greatly reduced. This is because there is no need to change the inspection device for each vacuum container to be inspected, it is easy to keep the inspection device (mass spectrometer) in a standby state at all times, and it is necessary to spray trace gas unnecessarily to various places. Because there is no. Helium is an expensive gas, but in the present invention, since a mixed gas of helium and neon is used, the amount of gas used for helium can be reduced to 1/30 or less of the conventional gas. did it.

<< In-Process Analysis of Residual Gas >> The continuous vacuum film forming apparatus shown in FIG. 1 is an apparatus for forming a functional thin film on a resin substrate. It has characteristics that greatly depend on conditions.
In particular, gas molecules that are contained or adhere to a resin substrate are less likely to be released than a glass substrate. This is because heat degassing and degassing cannot be performed at a high temperature like a glass substrate.
Therefore, the film is formed while evacuating with a clean vacuum pump having a high evacuation speed. However, depending on the state of the substrate, a large amount of gas such as moisture adhering to the surface may be generated in some cases. For this reason, it is necessary to stabilize the film formation quality by monitoring the atmosphere during the process during the evacuation, in particular, the background amount of the moisture, oxygen, and hydrocarbon gas species during the process. In the apparatus shown in FIG. 1, when no external leak occurred, the above-described in-process monitoring was performed by causing the mass spectrometer to function as a film formation quality monitoring apparatus. In this case, the atmosphere in the substrate transfer chamber 12 is changed to a mass spectrometer (the mass spectrometer analysis tube 30, the mass spectrometer processing device 3) during the film formation operation via the gas sampling path on the valve 28 side in FIG.
Monitoring was always performed in 2). Then, the water of interest (H
The allowable background peak values of ₂ O +) and oxygen (O ₂ +) are set in advance in the mass spectrometer processing device 32, and if the allowable values exceed the allowable values during operation, the leak monitoring device 33 is alerted. Function to emit

[Embodiment 2] FIG. 2 is a schematic configuration diagram of a continuous vacuum film forming apparatus showing another embodiment of the present invention, which is used for manufacturing a transparent conductive film for a liquid crystal display device (LCD). 1 shows an outline of a membrane device. One of the vacuum film forming apparatuses handled by the present inventors is such an in-line type sputtering apparatus, and also in this case, a large number of vacuum vessels (ch1 to ch6) 101 to 106 are arranged in a line (linear). A large number of sputtering cathodes are mounted for film formation, and this is a production apparatus for continuously (without releasing vacuum) forming ceramic-based thin films such as an ITO film and a protective film (eg, SiO ₂ ). . In this apparatus, sputtering is performed at high speed in each vacuum vessel, so that targets are frequently exchanged.
This is the same as the single-wafer sputtering apparatus for a phase-change optical disk described above.

In FIG. 2, six channels ch1 to ch6
Vacuum vessels 101 to 106 are connected linearly, and the vacuum vessels in contact with each other are gate valves 107, 108, 109,
Blocked or communicated at 110,111. One or more substrates to be processed are set on the substrate carrier 116. Reference numeral 101 denotes a first-stage vacuum vessel (ch) on the substrate loading side.
1), and reference numeral 106 denotes a sixth-stage vacuum vessel (ch6) on the substrate discharge side. Moreover, the vacuum container 1 of ch2 to ch5
Numerals 02 to 105 denote vacuum containers for film formation. The vacuum vessel 101 of ch1 is a so-called load lock chamber,
The substrate is set on 6 and vacuum degassing and degassing are performed at an appropriate temperature. The substrate handled by the apparatus of this embodiment is a polymer film substrate or a substrate on which a color filter is formed. In FIG. 2, a substrate carrier transport mechanism, a substrate heating mechanism, a nitrogen gas for vacuum vessel leak, a gas introduction system for sputtering, a vacuum gauge, and the like are not shown.

The substrate pre-processed (pre-processed) in the first-stage vacuum vessel (ch1) 101 is transferred to the second-stage vacuum vessel (ch2) 102 by the substrate carrier 116, where the underlayer (protection layer) is protected. 30) SiO ₂ thin film
A film of about 0 ° is formed. Here, since the film formation rate is 80 ° / sec by the RF magnetron sputtering method, the film formation is completed within 4 seconds. Thereafter, in the third to fifth vacuum vessels (ch3 to ch5) 103 to 105, an ITO thin film as a transparent conductive film is formed by using a DC magnetron sputtering method. In this case, 500Å for each vacuum vessel
Thus, the total film thickness is 1500 °.

In this embodiment, the film forming speed of ITO is 17 °
/ Sec, the film formation time in the vacuum vessels 103, 104, 105 is about 30 seconds each. The substrate carrier 116 on which the film formation has been completed is carried to the sixth-stage vacuum vessel (ch6) 106 and taken out. This vacuum vessel 106 is a so-called unload chamber. Vacuum containers 102 to 10 for performing film formation
5 is equipped with a sputtering cathode denoted by reference numeral 113 in FIG.
14 and a gas introduction system 115 are provided. The configuration of the sputtering cathode 113 and the closed container 114 is similar to that shown in FIG.
3. The sputtering cathode 202 and the sealed container 20 shown in FIG.
Corresponds to 8. The gas introduction system 115 has the configuration shown in FIG. 4, and the closed vessel 114 is supplied with a trace gas from the gas introduction system shown in FIG. This is the same as the case of [Embodiment 1] shown in FIG.

In the apparatus of this embodiment, each of the vacuum vessels 101 to 101
The common vacuum chamber 1 is normally shut off by a valve but can be connected to all vacuum vessels when necessary.
The common vacuum chamber 112 is provided with a turbo molecular pump 117, a valve 118 therefor, and a rotary pump 119. Further, the common vacuum chamber 112 and each of the vacuum vessels 101 to 106 are connected to a valve 120 to
125 are connected.

The common vacuum chamber 112 is provided with a gas sampling path provided with an orifice (pore) tube 126 and a valve 127 and a gas introduction valve 128 as in the apparatus of the first embodiment shown in FIG. The connected gas sampling path is connected to a mass spectrometer analysis unit (analysis tube) placed in a vacuum chamber (called a manifold or an envelope) 129.
130 and the differential exhaust device 131 are connected. Also,
The mass spectrometer analyzer tube 130 includes a mass spectrometer processor 132.
And the leak monitor 133 are connected to the common vacuum chamber 112
Is connected to a sensitivity calibration gas introduction system 134,
These configurations are the same as the configurations of the mass spectrometer processing device 32, the leak monitoring device 33, and the sensitivity calibration gas introduction system 34 of [Example 1] shown in FIG.

The apparatus (film forming apparatus) for producing a transparent conductive film for LCD shown in FIG. 2 performs high-speed continuous sputtering similarly to the apparatus of [Example 1]. Since replacement must be performed frequently, external leakage (air leakage) of the sputtering cathode portion is likely to occur. The thin film to be formed is a ceramic thin film, and generates a lot of particles, which also causes external leakage of the vacuum vessel. External leak detection method for sputtering cathode part is described in [Example 1].
Since the method and procedure are the same as those described above, the details are omitted, but it goes without saying that all valves indicated by 120 to 125 are kept open at the time of leak detection.

When there is no external leakage, c
The pretreatment state of the substrate in the vacuum vessel 101 indicated by h1 can be monitored by measuring the residual gas.
In this case, the valves 121 to 125 are all closed, and the residual gas in the vacuum vessel 101 is monitored, so that the gas released from the substrate and the state of the pretreatment (determination of the end point of the vacuum degassing process) even during the operation of the apparatus. Etc.) can be analyzed. Further, when the gas release in the vacuum vessel 101 is large and the pressure is high, the orifice (pore) tube 1
The amount of gas introduced into the mass spectrometer analysis tube 130 of the mass spectrometer can be limited using the gas sampling path on the side provided with 26 and the valve 127.

In the case of an in-line type vacuum film forming apparatus, in the conventional leak detection method, a helium leak detector is individually connected to each vacuum vessel in order to detect an external leak at a sputtering cathode portion and specify a leak location. Since the inspection was performed using a trace gas, an inspection time of 2 hours or more including the setup time was required even in a short case. However, as a result of applying the leak detection method of the present invention as the apparatus configuration shown in FIG. 2, if the mass spectrometer is in the operating state, it takes less than five minutes to complete the leak detection of the entire vacuum vessel. The inspection was able to be performed, and the inspection time was able to be greatly reduced.

[0076]

As described above, according to the leak detecting method for detecting atmospheric leakage of a plurality of vacuum containers of the vacuum film forming apparatus according to the first aspect, the atmospheric leakage from the outside to each vacuum container is detected. At the time of detection, a trace gas is used, and helium (He) and neon (N) are used as the trace gases.
Since the mixed gas of e) is used, the amount of helium used can be reduced. As shown in Example 1, the amount of helium used is reduced by 1/30 as compared with the leak detection method according to the prior art. We were able to reduce it below.

According to a second aspect of the present invention, there is provided a method for detecting atmospheric leakage of a plurality of vacuum vessels in a vacuum film forming apparatus.
When detecting external air leaks to each vacuum vessel, inspect each vacuum vessel at the same time because the mixing ratio of helium and neon in the trace gas blown to each vacuum vessel differs for each vacuum vessel. Therefore, the location of the air leak from the outside can be identified very quickly as compared with the case where the detection is performed using a single helium. Although two hours were required, the method of the present invention was able to perform an atmospheric leakage inspection of all vacuum containers within four minutes.

According to a third aspect of the present invention, there is provided a method for detecting atmospheric leakage of a plurality of vacuum vessels in a vacuum film forming apparatus.
When detecting atmospheric leakage from the outside of multiple vacuum vessels,
Aside from the individual vacuum vessels in which the workpiece is loaded or unloaded or subjected to vacuum film formation, a common vacuum space communicating with each vacuum vessel is provided, and the atmosphere and trace gas leaked from each vacuum vessel into this vacuum space. Is detected by a mass spectrometer.Therefore, it is possible to detect leaks in each vacuum vessel one by one, or to connect the vacuum of all vacuum vessels to the whole vacuum system. There is no need to sequentially check for leaks by spraying a trace gas on a certain site. Therefore, air leakage can be detected even during operation of the apparatus without consuming a large amount of helium gas.
In addition, since the partial pressure peak of the trace gas is detected using a mass spectrometer, the effect of the partial pressure of nitrogen and oxygen remaining in the vacuum vessel differs from the case where the leak is judged based on the partial pressure of nitrogen and oxygen. You don't have to.

According to a fourth aspect of the present invention, in the leak detecting method according to the third aspect, before detecting the partial pressure of the trace gas leaking into the common vacuum space,
A trace gas containing equal amounts of helium and neon in a molar ratio (mixing ratio is 1: 1) is caused to flow in a common vacuum space, and the sensitivity coefficient of the mass spectrometer for the helium and neon gas species is set in advance to determine the partial pressure. Since the partial pressure of the trace gas is detected after the sensitivity calibration of the mass spectrum intensity is performed, the partial pressure ratio of helium and neon can be accurately obtained even when the analysis conditions such as ionization voltage (ionization voltage) change. It is possible to grasp the ratio of helium to neon gas in the vacuum vessel. Further, based on the data of the abundance ratio, the location where the external leak occurs can be specified in a very short time as shown in the first and second embodiments.

According to a fifth aspect of the present invention, there is provided a film forming quality monitoring apparatus comprising: a vacuum film forming apparatus comprising a plurality of vacuum vessels; Detect and monitor the film formation quality, using a mass spectrometer to detect residual gas in the common vacuum space communicating with each vacuum vessel and the atmosphere leaking into this vacuum space, trace gas, The mass spectrometer is provided with both a gas sampling path having a pore (orifice) for taking in a part of the gas in the vacuum vessel while reducing the pressure, and a gas sampling path having no pore. Since the vacuum space in which the analyzer is installed is provided with a differential evacuation device, it is not limited to the degree of vacuum (pressure) of the vacuum container to be subjected to a leak test, and the vacuum container for checking an external leak is not limited. When vacuum pressure is high It can perform partial pressure measurement limit the amount of gas flowing into the mass spectrometer side accordingly on. Further, since the quality of the residual gas before performing the film forming process in the vacuum vessel, that is, the background, can be measured in-process as in the first and second embodiments, the stabilization of the film forming quality is easy. .

In the continuous vacuum film forming apparatus comprising a plurality of vacuum vessels according to the present invention, when detecting atmospheric leakage from the outside of the sputtering cathode attached to the plurality of vacuum vessels, Since the atmosphere side of the sputtering cathode is sealed with a sealed container, and a mixed gas of helium and neon is supplied to this sealed container as a trace gas for detecting atmospheric leakage, the sputtering cathode portion as shown in Example 1 The location of the external leak can be identified in a very short time. In addition, since there is no need to install a detection device such as a mass spectrometer for each vacuum vessel or to switch the detection device for each vacuum vessel,
As a means for improving the operability of the vacuum film forming apparatus, a great economic effect is obtained.

In the continuous vacuum film forming apparatus comprising a plurality of vacuum vessels according to the present invention, when detecting atmospheric leakage from the outside of the sputtering cathode attached to the plurality of vacuum vessels, the apparatus may be subjected to the following. Aside from the individual vacuum vessels in which the processing object is loaded or unloaded or vacuum film-formed, a common vacuum space communicating with each vacuum vessel is provided, and the atmosphere and trace gas leaked from each vacuum vessel into this vacuum space are removed. By detecting the partial pressure by the mass spectrometer, it is possible to easily detect the external leak of the entire apparatus by connecting only one mass spectrometer. In addition, there is no need to interrupt the film forming operation of the apparatus and change the mass spectrometer as in the prior art,
Leakage detection can be performed efficiently while the device is operating.

In the continuous vacuum film forming apparatus comprising a plurality of vacuum vessels according to the present invention, each vacuum vessel is provided separately from an individual vacuum vessel in which an object to be processed is loaded or unloaded or subjected to vacuum film deposition. Has a common vacuum space that communicates with the container,
When detecting the residual gas partial pressure in the vacuum space, the atmosphere leaking into the vacuum space, and the trace gas, by providing the film formation quality monitoring device according to claim 5, an external leak detection device is provided. This eliminates the need for double capital investment to prepare a separate background measurement device.If there is an external leak, the sputtering cathode site where the external leak occurs can be immediately identified, and if there is no external leak, The background monitoring during the film formation process can be performed in-process.

In the continuous vacuum film forming apparatus comprising a plurality of vacuum vessels according to the present invention, when detecting atmospheric leakage (external leak) from outside the sputtering cathode attached to the vacuum vessel. In addition to the individual vacuum vessels in which the workpiece is loaded or unloaded or subjected to vacuum film formation, a common vacuum space communicating with each vacuum vessel is provided, and the atmosphere leaking from each vacuum vessel to this vacuum space and The partial pressure of the trace gas is detected by a mass spectrometer, and the mixing ratio of helium and neon of the trace gas sprayed on each vacuum vessel varies from vacuum vessel to vacuum vessel. Since it is specified, consumption of expensive helium gas can be reduced. In addition, the location of the external leak can be immediately specified by the peak intensity ratio between helium and neon when measuring the partial pressure. In addition, since it is not necessary to change the detection device for each vacuum vessel, the capital investment can be reduced, and the detection can be performed even during the operation of the film forming device, so that the operability and the yield can be improved at the same time. The specific effects are as shown in the first and second embodiments.

In the continuous vacuum film forming apparatus comprising a plurality of vacuum vessels according to the present invention, when detecting atmospheric leakage (external leak) from outside the sputtering cathode attached to the vacuum vessel. In addition to the individual vacuum vessels in which the workpiece is loaded or unloaded or subjected to vacuum film formation, a common vacuum space communicating with each vacuum vessel is provided,
The partial pressure of the atmosphere and trace gas leaked from each vacuum vessel into this vacuum space is detected by a mass spectrometer, and the mixing ratio of helium and neon of the trace gas blown to each vacuum vessel is different for each vacuum vessel. A monitoring device that immediately identifies the sputtering cathode that has leaked, identifies the sputtering cathode that has detected an atmospheric leak based on the measurement results of the mass spectrometer, and issues an alarm provides a high level of accuracy. The location where an external leak occurs can be specified without stopping the operation of a continuous vacuum film forming apparatus that performs a film forming process at a high speed, and can be confirmed by an alarm. For this reason, it is possible to prevent a trouble that the processed substrate is subsequently processed with poor quality and causes a large loss.

[Brief description of the drawings]

FIG. 1 is a schematic configuration diagram of a continuous vacuum film forming apparatus showing one embodiment of the present invention.

FIG. 2 is a schematic configuration diagram of a continuous vacuum film forming apparatus showing another embodiment of the present invention.

FIG. 3 is a cross-sectional view of an essential part showing a configuration example of a sputtering cathode and a sealed container installed in a film forming vacuum vessel of the vacuum film forming apparatus shown in FIG. 1 or 2;

4 is a diagram showing an example of a gas introduction system connected to a gas introduction port of the closed container shown in FIG.

FIG. 5 shows five kinds of rare gases (He, Ne,
FIG. 7 is a graph showing the analysis results of Ar, Kr, and Xe), and is a graph showing the relationship between the mass numbers (m / e) of five rare gases and the relative sensitivity when nitrogen gas is set to 1.0 (reference). is there.

FIG. 6 is a diagram showing the measurement results of the partial pressure of a mixed gas of helium (He) and neon (Ne), where (a) shows He: N.
A graph showing the partial pressure with respect to the mass number (m / e) of the mixed gas of e = 1: 2, and (b) shows the partial pressure with respect to the mass number (m / e) of the mixed gas of He: Ne = 1: 4. It is a graph.

[Explanation of symbols]

1-8: Vacuum container 9: Cathode for sputtering 10: Sealed container 11: Gas inlet (He or He / Ne mixed gas inlet) 12: Substrate transfer chamber 13: Substrate transfer rotary arm 14: Rotary pump 15: Valve 16 : Roughing valve 17: Turbo molecular pump (for ch8) 18: Valve 19: Mechanical booster pump 20: Rotary pump 21: Turbo molecular pump 22: Valve 23 to 25: Turbo molecular pump exhaust system 26: Orifice (pore) tube 27: Valve 28: Valve 29: Vacuum chamber (manifold) 30: Mass spectrometer analyzer tube 31: Differential pumping device 32: Mass spectrometer processing device 33: Leak monitoring device 34: Sensitivity calibration gas introduction system 35: O- Rings 101 to 106: Vacuum container 107 to 111: Gate valve 112: Common vacuum chamber 113: cathode for sputtering 114: closed vessel 115: gas inlet (He or He / Ne mixed gas inlet) 116: substrate carrier 117: turbo molecular pump 118: valve 119: rotary pump 120 to 125: valve 126: orifice ( (Pore) tube 127: valve 128: valve 129: vacuum chamber (manifold) 130: mass spectrometer analysis tube 131: differential pumping device 132: mass spectrometer processing device 133: leak monitoring device 134: sensitivity calibration gas introduction system 201: vacuum vessel wall 202: cathode body for sputtering 203: backing plate 204: target material 205: O-ring seal part 206: cooling water introduction pipe 207: cooling water 208: closed vessel 209: gas introduction port (He or He / Ne mixed gas inlet) 2 0: Magnet 211: shield plate (ground shield) 212: insulating plate

 ──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Yuji Miura 1-3-6 Nakamagome, Ota-ku, Tokyo, Ricoh Co., Ltd. (72) Inventor Kiyoto Shibata 1-3-6 Nakamagome, Ota-ku, Tokyo Ricoh Co., Ltd. (72) Inventor Yasuchi Aman 1-3-6 Nakamagome, Ota-ku, Tokyo, Ricoh Co., Ltd.

Claims (10)

[Claims] In a vacuum film forming apparatus comprising a plurality of vacuum vessels, there is provided a leak detection method for detecting leaks of the vacuum vessels, wherein when detecting atmospheric leakage to the respective vacuum vessels from the outside, A method for detecting a leak in a vacuum vessel, wherein a trace gas is used, and a mixed gas of helium (He) and neon (Ne) is used as the trace gas. 2. A leak detecting method for detecting a leak in the vacuum vessel in a vacuum film forming apparatus including a plurality of vacuum vessels, wherein when detecting atmospheric leak from the outside to each vacuum vessel, A method of detecting leakage of a vacuum vessel, wherein a mixing ratio of helium and neon of a trace gas blown to each vacuum vessel is different for each vacuum vessel. 3. A leak detection method for detecting a leak in the vacuum vessel in a vacuum film forming apparatus comprising a plurality of vacuum vessels, wherein an object to be processed is detected when an atmospheric leak from outside the vacuum vessel is detected. Has a common vacuum space that communicates with each vacuum vessel separately from the individual vacuum vessels that are loaded or unloaded or vacuum film-formed, and the partial pressure of the atmosphere and trace gas leaked from each vacuum vessel into this vacuum space Detecting the leakage of the vacuum vessel by a mass spectrometer. 4. The method for detecting leakage of a vacuum vessel according to claim 3, wherein a trace gas containing an equal amount of helium and neon in a molar ratio is detected before detecting the partial pressure of the trace gas leaking into the vacuum space. A vacuum characterized by flowing in the vacuum space, previously taking the sensitivity coefficient of the mass spectrometer for the helium and neon gas species, performing the sensitivity calibration of the partial mass spectrum intensity, and then detecting the partial pressure of the trace gas. Container leak detection method. 5. A film forming quality for monitoring a film forming quality by detecting a leak in the vacuum container using a leak detecting method according to claim 3 in a vacuum film forming apparatus comprising a plurality of vacuum containers. A monitoring device, which uses a mass spectrometer to detect residual gas in a common vacuum space communicating with each vacuum vessel, the atmosphere leaking into the vacuum space, and trace gas, and the mass spectrometer has a vacuum. A vacuum space having both a gas sampling path having a pore (orifice) for taking in a part of the gas in the container while reducing the pressure and a gas sampling path having no pore, and in which the mass spectrometer is installed. Is provided with a differential evacuation device. 6. A continuous vacuum film forming apparatus comprising a plurality of vacuum vessels, wherein when detecting atmospheric leakage from the outside of a sputtering cathode attached to said vacuum vessel,
The sputtering cathode is sealed on the atmosphere side with an airtight container, and a trace gas for detecting air leakage is supplied to the airtight container, and the trace gas is a mixed gas of helium and neon. Membrane equipment. 7. A continuous vacuum film forming apparatus comprising a plurality of vacuum vessels, wherein when detecting atmospheric leakage from the outside of a sputtering cathode attached to said vacuum vessel,
Aside from the individual vacuum vessels in which the workpiece is loaded or unloaded or subjected to vacuum film formation, a common vacuum space communicating with each vacuum vessel is provided, and the atmosphere and trace gas leaked from each vacuum vessel into this vacuum space. A continuous vacuum film forming apparatus, wherein a partial pressure of the liquid is detected by a mass spectrometer. 8. A continuous vacuum film forming apparatus comprising a plurality of vacuum vessels, which is connected to each vacuum vessel separately from individual vacuum vessels in which an object to be processed is loaded or unloaded or subjected to vacuum film deposition. And a film quality monitoring device according to claim 5 for detecting a residual gas partial pressure in the vacuum space, an atmosphere leaking into the vacuum space, and a trace gas. A continuous vacuum film forming apparatus characterized by the above-mentioned. 9. A continuous vacuum film forming apparatus comprising a plurality of vacuum vessels, wherein when detecting atmospheric leakage from the outside of a sputtering cathode attached to said vacuum vessel,
Aside from the individual vacuum vessels in which the workpiece is loaded or unloaded or subjected to vacuum film formation, a common vacuum space communicating with each vacuum vessel is provided, and the atmosphere and trace gas leaked from each vacuum vessel into this vacuum space. Is detected by a mass spectrometer, and the mixing ratio of helium and neon of the trace gas sprayed to each vacuum vessel is different for each vacuum vessel, thereby immediately identifying the sputtering cathode that is leaking to the atmosphere. A continuous vacuum film forming apparatus characterized by the above-mentioned. 10. A continuous vacuum film forming apparatus comprising a plurality of vacuum vessels, wherein when an atmospheric leak from the outside of a sputtering cathode attached to the vacuum vessel is detected, an object to be processed is carried in. Or, apart from the individual vacuum vessels that are carried out or subjected to vacuum film formation, a common vacuum space that communicates with each vacuum vessel is provided, and the partial pressure of the atmosphere and trace gas leaked from each vacuum vessel to this vacuum space is measured. The mixing ratio of helium and neon in the trace gas that is detected by the analyzer and sprayed on each vacuum vessel is different for each vacuum vessel, so that the sputtering cathode that is leaking to the atmosphere can be immediately identified, and the mass spectrometer Continuous vacuum deposition characterized by having a monitoring device that identifies the sputtering cathode for which atmospheric leakage was detected based on the measurement results and issues an alarm Location.