JPH10152772A - Sputtering method and apparatus therefor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To form uniform thin films stably from the initial period to the end period of a target life on a large-sized substrate by controlling the electric power to be impressed on the electrodes on an end part side and electrodes exclusive thereof or the electric power impression time thereof during sputtering. SOLUTION: Targets 2a, 2b, 2c are arranged on three electrode plates 1a, 1b, 1c electrically insulated from each other within the plane facing the substrate 5 held in a vacuum chamber and the films are formed on the substrate 5 in the static state with respect to these targets. In this sputtering method, the electrodes 1a, 1b, 1c and the targets 2a, 2b, 2c are arranged at equal intervals and the apparatus is provided with a controller 26 capable of respectively independently controlling the electric power to be impressed on power sources 3a, 3b, 3c connected to the electrodes 1a, 1b, 1c. The magnitude of the electric power to be impressed on the respective electrodes 1a, 1b, 1c and the electric power impression time are independently changed during the sputtering.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a sputtering method and a sputtering apparatus for forming a thin film on a substrate, and more particularly to a method for forming a thin film having a uniform thickness on a large area, such as a liquid crystal substrate. It can be applied to the production of

[0002]

2. Description of the Related Art A sputtering apparatus is widely used as a film forming apparatus for stably producing a thin film composed of a target material or the like on a substrate, in the production of thin film products such as semiconductors, liquid crystal substrates, and optical disks. The characteristics required for the film forming apparatus are 1) that a film having uniformity and high quality can be stably manufactured, 2) that the film forming speed is high and that productivity is high, and 3) that the cost of the apparatus and the operating cost are low. And 4) little change in characteristics from the beginning to the end of use of the device or from immediately after maintenance to immediately before the next maintenance. The sputtering apparatus is a film forming apparatus utilizing a sputtering phenomenon caused by discharge of an inert gas introduced into a high vacuum. The configuration and operating principle of a typical device will be described below. The film forming apparatus was provided in a vacuum chamber provided with a vacuum exhaust device and a gas supply device, a substrate holding device for holding a substrate, an electrode capable of applying power in opposition to the substrate holding device, and installed on the electrode. A target to be a thin film material. By supplying an inert gas or the like from the gas supply device into the vacuum chamber and applying a negative voltage or high-frequency power to the electrode, plasma is generated between the substrate and the target, and atoms of the inert gas are removed. It is ionized, accelerated by the electric field, and collides with the target. Then, a sputtering phenomenon occurs on the target, and material atoms sputtered from the target adhere to the substrate to form a thin film.

The above-mentioned sputtering apparatus has excellent advantages such as a relatively simple apparatus configuration. on the one hand,
Since plasma due to discharge is widely distributed between the substrate and the target, 1) the substrate is largely damaged by the plasma, 2) the sputtering rate on the target is low, and the deposition rate is low; There is a problem in that power must be supplied and power cost is high, and it is necessary to periodically remove the film adhering to places other than the substrate, and maintenance cost is high. A method called magnetron sputtering solves these problems. This is to generate a magnetic field on the target and trap electrons by the magnetic field. According to this method, the plasma is concentrated in the vicinity of the target, and 1) the plasma damage of the substrate is small, 2) the plasma density on the target is high, the deposition rate is high, and 3) the power cost is low. And most of today's sputtering apparatuses are magnetron sputtering apparatuses.

Next, FIG. 13 shows an example of the configuration of a conventional general magnetron sputtering apparatus. In FIG. 13, an exhaust device 7 and a gas introduction unit 6 are provided in a vacuum chamber 12. Further, a substrate 5 is provided on the substrate holder 4, and a plurality of magnets 11 are provided in the electrode 1 immediately below the target 2. The electrons have a property of gradually drifting on the target 2 in a direction perpendicular to the magnetic field. Therefore, it is common to place the tunnel of the magnetic field in a ring to obtain a higher density plasma so that the electrons drift as long as possible. As a result, a portion having a high plasma density is generated in a portion where the magnetic field is strong on the target 2, and as a result, this portion is sputtered faster than other portions. The valley-shaped portion on the target 2 generated in this way is called “erosion”. In sputtering, since atoms sputtered from the target 2 have a certain radiation angle distribution, in the case of a stationary facing method in which a film is formed while the substrate is stationary with respect to the target, the shape and size of the substrate to be film-formed Therefore, it is necessary to optimize a target shape, a magnet structure, its size, and the like. FIG.
Numeral 4 shows a typical arrangement of the target 2 and the magnet 11 in magnetron sputtering, and a relationship between erosion and film thickness distribution. In FIG. 14, a plurality of magnets 11 are provided immediately below the target 2. Due to the magnetic field 14 generated by the magnet 11, a portion 15 having a high plasma density is generated during the discharge, and the thickness of the film 13 on the substrate 5 changes correspondingly. Substrate 5
The area where the film can be formed with a relatively uniform film thickness is generally as large as the size of the erosion. Usually, uniform film formation is realized by making the area of the target 2 about twice or more the area of the target substrate 5.

When a film is formed on a large-sized substrate 5 such as a liquid crystal, it is increasingly required that the film be formed at a high speed at a low cost and stably. When a film is formed on the large-size substrate 5 by a sputtering apparatus, it is particularly important to ensure uniformity of the film thickness over the entire surface of the substrate 5, to reduce the cost and size of the apparatus, and to minimize the change with time. Conventionally, when sputtering is performed on such a large-sized substrate, at least one of the vertical and horizontal dimensions of the substrate is prepared, an extremely large vacuum chamber is prepared, and a film is formed while moving the substrate with respect to the target. The tray method was generally used.
According to this method, film thickness uniformity over the entire surface of the substrate can be obtained relatively easily. However, today, demands for reduction of equipment costs by reducing the size of equipment and reduction of clean room costs by reducing the installation area, etc. There is a demand for a single-wafer stationary facing type sputtering apparatus that forms a film on each substrate.

In the above-mentioned single-wafer stationary facing type sputtering apparatus, as a method for securing the film thickness uniformity of the film formed on the substrate, a method of forming a film while moving a magnet provided on the back surface of the target is well known. Have been.
FIG. 15 shows this configuration. In FIG. 15, a plurality of magnets 11 are installed on a magnet drive mechanism 16 on the back surface of the target 2.
6, the screw shaft 16b is rotated forward and reverse by rotating the motor 16a, and the magnet table 16d fixed to the moving body 16c screwed to the screw shaft 16b is moved left and right in FIG. The fixed plurality of magnets 11 oscillate in the left-right direction in FIG. 15, thereby preventing erosion of the target surface from locally proceeding, and stably and uniformly from the beginning to the end of the life of the target. Film formation can be performed. However, this method requires the magnet drive mechanism 16, and the device becomes complicated. Further, the film thickness uniformity is determined by the moving speed of the magnet 11, but it is difficult to adjust the turning speed at the left and right ends of the moving region of the magnet 11, and the film thickness uniformity of the film formed on the substrate is secured. There is a problem that it is difficult to do. Furthermore, when high-frequency discharge is caused, there is a problem that a high-frequency matching state changes depending on the position of the magnet 11, and stable discharge is hard to occur.

When a substrate such as a liquid crystal is large, the size of the target is an important problem. For example, consider a case where a thin film is to be uniformly formed on a substrate of about 400 mm × 500 mm which is currently the mainstream of liquid crystal substrates. The size of the target is 600 even assuming twice the area of the substrate.
It becomes a size of mm × 700 mm. Assuming that the thickness of the target is 10 mm, the weight of an aluminum target often used as a wiring film such as a semiconductor also weighs 10 kg or more. This weight becomes heavier if the specific gravity of the target material is heavy. Further, since the backing plate attached to the target needs to withstand vacuum, it has to be about 30 mm thick, and the electrode unit weighs 100 kg or more. In a manufacturing plant, this electrode unit must be replaced about once a week or about once a month. However, since it is impossible to replace such a heavy target by hand, a special jig is prepared. Requires a large work space, and there is a great danger in work. In the case of manufacturing such a huge target, a furnace and the like are also increased in size, so that the price per area of the target is increased.

[0008] In order to solve the above problem, a target is divided. To divide the target, (1) one in which a plurality of targets are attached to one backing plate, (2) one in which a plurality of targets are attached to a backing plate, and each is attached to a single electrode, (3) a plurality of targets Some targets are attached to a backing plate, and each is attached to a separate electrode. When a plurality of targets of the above (1) are attached to a single backing plate, it is effective in reducing the target manufacturing cost, but the weight of the target does not change. To solve the problem of target weight and size, the above (2) or (3)
Method is needed. In the case of the above (2), it is possible to arrange erosion over a plurality of targets and treat them as if they were a single target. But,
It is not preferable that erosion is present over a plurality of targets because abnormal discharge occurs at a break in the target or a backing plate material is sputtered and mixed into the film. Therefore, the above (2)
In this case, it is desirable that erosion exists in each target.

When a plurality of electrode units having exactly the same configuration are arranged at equal intervals and the same erosion is arranged at equal intervals to form a film, the film thickness on the erosion at both ends is smaller than that at the center. There's a problem. This is because particles scattered from one erosion adhere to the substrate on the next erosion. As a means for solving this, the number of sputter particles adhering to the substrate from erosion at both ends may be larger than the number of sputter particles adhering to the substrate from other erosion. For example, in the method described in JP-A-6-192833, the strength of the magnets provided behind the targets at both ends is made stronger than the magnets provided behind the other targets. As a result, sputter particles attached to the substrate from erosion at both ends are increased. Or, Tokujin Sho 6
In the method described in Japanese Patent Application Laid-Open No. 3-61387, the targets at both ends are set to be slightly inclined with respect to the other targets, and the sputter particles substantially attached to the substrate from the targets at both ends are increased. In these methods, when the scattering angle of the sputtered particles from each target is constant, it is possible to prevent the film thickness of the film at both ends from deteriorating and to improve the film thickness uniformity. However, in sputtering, the scattering angle of sputtered particles changes between the early stage and the last stage of the target life. Therefore, these methods cannot maintain uniformity from the beginning to the last stage of the target life.

In sputtering, it is known that the film thickness distribution on the substrate changes between the early stage and the last stage of the target life. In general, the film thickness distribution of a film obtained from one target due to the progress of erosion changes according to the following equation called Lambert's cos law.
It changes as shown in FIG.

(Equation 1) Here, Ri is the film thickness at a certain point P on the substrate, A is a minute unit area on the erosion, and L is a minute unit area A from the point P.
Distance, h is the distance between the target and the substrate, Rv
Is the amount of sputtered particles scattered from the minute unit area A. In this equation, n represents the scattering angle distribution of sputtered particles, and the scattering angle is concentrated in a narrower range as n is larger. n is usually about 1, but may reach 3 around the life of the target.

[0011]

As described above, as described above,
When forming a film on a large-sized substrate such as a liquid crystal by a stationary facing method, it is extremely important to form a film while ensuring uniform film thickness from the beginning to the end of the target life.
An object of the present invention is to provide a sputtering method and a sputtering apparatus capable of forming a thin film having a uniform thickness stably from the beginning to the end of the life of a target.

[0012]

SUMMARY OF THE INVENTION In order to achieve the above-mentioned object, the present invention provides an electric power or an electric power application time applied to an electrode on an end portion among a plurality of electrodes to which electric power can be independently applied. Is controlled during sputtering so as to increase or decrease with respect to the power applied to the other electrodes other than the end side or the power application time. That is, according to the first aspect of the present invention, three or more substrates electrically isolated from each other are held in a plane facing the substrate by holding the substrate in a vacuum chamber having a gas supply and exhaust function. In a sputtering method in which a target is arranged on an electrode plate and the substrate is formed in a state where the substrate is stationary with respect to the target, all or at least one of the electrodes arranged on the end side of the electrodes and the end During the sputtering, the power applied to the electrode or the power application time is controlled so as to be different between the electrode other than the electrode on the side of the unit and the electrode. According to a second aspect of the present invention, in the first aspect, the depth of the deepest portion of the erosion region on the target is measured, and based on the measurement result,
It is also possible to control the difference in power or power application time between the electrodes. According to a third aspect of the present invention, the second
In an embodiment, the depth of the eroded area on the target may be measured by a contact or non-contact type surface profile measuring device. According to the fourth aspect of the present invention, in the first aspect, the film is formed by making the film thickness distribution when each of the above targets is formed alone, or equalizing the power applied to each target or the power application time. In this case, it is also possible to measure the film thickness distribution and control the power or the difference in power application time between the electrodes based on the measurement result. According to the fifth aspect of the present invention, in the fourth aspect, the thickness of the film formed on the substrate may be measured by the film thickness measuring means.

According to a sixth aspect of the present invention, there is provided a sputtering apparatus for forming a film while a substrate is stationary with respect to a target, comprising: a vacuum chamber having a gas supply and exhaust function;
A substrate supporting portion for holding the substrate, three or more electrodes arranged on a plane facing the substrate, and three or more electrodes arranged on a plane facing the substrate, respectively; And a power applied to the electrodes during sputtering between all or at least one of the electrodes arranged on the end side of the electrodes and electrodes other than the electrodes on the end side. Alternatively, there is provided a control device for controlling the power supply so as to make the power application time different. According to a seventh aspect of the present invention, in the sixth aspect, further includes a contact or non-contact surface shape measuring device for measuring a depth of a deepest portion of the erosion region on the target, wherein the control device includes: Based on a result of the measurement of the depth by the measuring device, a difference in power or a power application time between the electrodes may be controlled. According to the eighth aspect of the present invention, in the sixth aspect, the film formation is performed with the film thickness distribution when the above-described targets are formed alone, or the power applied to each target or the power application time is made uniform. The apparatus further includes a film thickness measurement device that measures a film thickness distribution in the case where the control device determines a difference in power or power application time between the electrodes based on a measurement result of the film thickness distribution by the film thickness measurement device. It can also be controlled.

[0014]

According to the present invention, even for a substrate having a large area, by using a plurality of small targets and independently controlling the power or the power application time applied to each electrode corresponding to each target, From the beginning to the end of the target life, uniform film formation can be stably realized over the entire surface of the substrate. Therefore, there is no need for a mechanism for moving the magnet as in the conventional device, which simplifies the structure of the device and enables stable matching even when a high-frequency discharge is applied. Film formation and film formation of a compound thin film by reactive sputtering can be performed stably. Further, the shape of the target surface is measured by, for example, measuring the amount of digging of the target, and the power or the power application time applied to the target on the electrode on the end side and the target on the electrode other than the end side are independently determined. By controlling, a film with high uniformity can always be stably formed according to the situation in the vacuum chamber. In addition, the thickness of the formed thin film is monitored as needed, and based on the result, the power applied to the target of the electrode on the end side and the target of the other electrode other than the end side or the power application time is independently controlled. By doing so, the thin film can be uniformed more accurately. In particular, if the thickness of the film formed by a single target is measured, and the power or power application time to be applied to the target on the end side or the target other than the end side is determined from the result, and the control is performed, The film thickness can be made more uniform.

[0015]

BEST MODE FOR CARRYING OUT THE INVENTION

(First Embodiment) Next, a first embodiment of the present invention will be described with reference to the drawings. FIG. 1 is a schematic perspective view of a sputtering apparatus for performing a sputtering method according to a first embodiment of the present invention. In the first embodiment,
Three electrodes 1a, 1b, 1c and targets 2a, 2
b, 2c are arranged at equal intervals as shown in the figure, and power supplies 3a, 3b, 3c connected to the electrodes 1a, 1b, 1c.
And a control device 26 for controlling the power applied to each of the power supplies 3a, 3b, 3c. Substrate 5 is target 2
a, 2b, 2c. The control device 26 enables the power supplies 3a, 3b, 3c for applying power to the electrodes 1a, 1b, 1c to be independently controlled, and during the sputtering, the respective electrodes 1a, 1b, 1c.
It is possible to independently change the magnitude of the power to be applied and the power application time. The operation of the sputtering apparatus configured as described above will be described below.

In the first embodiment, the control device 26 controls each of the electrodes 1 from the power sources 3a, 3b, 3c.
FIG. 2 shows an example in which the film thickness of the film formed on the substrate 5 when power is uniformly applied to a, 1b, and 1c is obtained by simulation. However, the above film thickness is normalized by assuming that the film thickness at the center is 1. 2, a solid line 21 indicates the thickness of the film formed at the position of the AA cross section on the substrate 5 in FIG. In FIG. 2, a broken line 22 indicates a simulation of the thickness of a film obtained separately from each of the targets 2 a to 2 c, and a solid line 21 is obtained by adding these. As can be seen from FIG. 2, the film thickness at both ends of the substrate 5 is smaller than that at the center. On the other hand, FIG. 3 shows the result of changing the power applied from the power supplies 3a and 3c to the electrodes 1a and 1c at both ends while the power applied from the power supply 3b to the center electrode 1b is kept constant by the control device 26. Show. However, as in FIG. 2, the film thickness of the film formed on the substrate 5 is normalized with the film thickness at the center being 1. In FIG. 3, the electrodes 1 at both ends are
The power applied to a and 1c is increased by 12% with respect to the power applied to the center electrode 1b. As a result, the drop in the film thickness of the film at both end portions of the substrate 5 shown by the solid line 21 is eliminated as shown by the solid line 31. In FIG. 2, the uniformity of the film thickness within the substrate surface is ± 8%, but in FIG. 3, it is improved to ± 4%. The film thickness of the film separately obtained from each of the targets 2a to 2c shown by the broken line 22 in FIG. 2 is actually the material of the target, the type of gas, the film forming pressure, the discharge power, and the difference between the target and the substrate. It also changes depending on the distance between them. When the deposition pressure is high or when the distance between the target and the substrate is large, the broken line 2
2 tends to be smoother. In this case, the control device 26 controls the both-end electrodes 1a and 1c in FIG.
By increasing the power increase by 12% in
More uniform film formation becomes possible. Conversely, when the film formation pressure is low or the distance between the target and the substrate is small, a more uniform growth can be achieved by reducing the power increase 12% at the electrodes 1a and 1c at both ends. In some cases, a membrane can be achieved.

Next, FIG. 4 shows an example in which the film thickness distribution changes with the lapse of time from the example shown in FIG. In FIG. 4, the scattering angle of the particles scattered from each erosion due to local depletion of the target is smaller than that in FIG. Therefore, when the power applied to the electrodes 1a and 1c at both ends is increased by the control device 26 in the same manner as in the initial stage of the sputtering, the film thickness at both ends on the substrate is slightly larger than that at the center as shown in FIG. turn into. Therefore, the controller 1 controls the electrodes 1 of the targets 2a and 2c at both ends.
FIG. 5 shows an example in which the uniformity of the film is ensured by controlling the power applied to a and 1c. In FIG. 5, as indicated by the broken line 52,
By the control device 26, the targets 2a and 2c at both ends are
By making the power applied to the electrodes 1a and 1c equal to the power applied to the central electrode 1b, the film thickness uniformity on the substrate is ensured. Thus, the targets 2a,
By controlling the power applied to the electrodes 1a and 1c at both ends with respect to the power applied to the center electrode 1b in accordance with the consumption of the electrode 2c, the power is uniformly applied on the substrate from the beginning to the end of the target life. It is possible to form a thin film on the substrate. According to the first embodiment, even for a large-area substrate, a plurality of small targets 2a to 2c are used and the power applied to each electrode 1a to 1c corresponding to each target 2a to 2c or the power application time is independent. By the control by the controller 26, uniform film formation can be realized over the entire surface of the substrate from the beginning to the end of the target life.

(Second Embodiment) A sputtering apparatus for carrying out a sputtering method according to a second embodiment of the present invention will be described with reference to FIG. In the second embodiment, in order to measure the erosion depth of the targets 2a to 2c, the targets 2a to 2c are placed in a vacuum chamber.
a surface shape measuring device 8 for measuring the surface shape of each of a to 2c is provided, and information of a measurement result measured by the measuring device 8 is input to the control device 26 to control the power or the power application time. It can be used.
The measuring device 8 may be always in a film forming region in a vacuum chamber, but in order to prevent film adhesion to the measuring device 8,
During the film formation, it may be hidden by a portion partitioned by the shielding plate 9 or the like (see 8 'in FIG. 6), and may come out only when the film is not formed. As the measuring device 8, a contact type shape measuring device that contacts a film formed on the substrate 5 may be used. However, as shown in FIG. 6, an optical type using a laser or the like is used to maintain the cleanliness of the target surface. It is desirable to use a non-contact shape measuring device.

In the second embodiment, the measuring device 8
Is to measure the surface shape of the targets 2a to 2c by measuring the depth of the deepest part of the erosion region on the targets 2a to 2c. The control device 26 independently controls the power or the power application time between the electrodes 1 a to 1 c based on the measurement result of the depth by the measurement device 8 so that each of the electrodes 1 a to 1 c has an optimum value. A thin film can be formed thereon. Here, the control based on the measured values of the surface shape will be described in more detail. The largest value among the measured values of the depth obtained from each target in the measuring device 8 is defined as the measured value of the deepest part. On the other hand, a table indicating the relationship between the power applied to the electrode and the power application time with respect to the target depth is stored in advance in a memory in the control device 26, and the measurement is performed by referring to the table based on the measured value. The power or the power application time to be applied to the electrode corresponding to the target thus determined is obtained, and the control device 26 controls the value to be the value. According to the second embodiment, in addition to the functions and effects of the first embodiment, the shape of the target surface is measured by measuring the depth of the deepest portion of the erosion region on the targets 2a to 2c. , Target 2 on electrodes 1a, 1c on the end side
Since the power applied to the target 2a and the target 2b of the electrode 1b other than the end side are independently controlled, the uniformity is always stable and high according to the situation in the vacuum chamber. A film can be formed.

(Third Embodiment) A sputtering apparatus for performing a sputtering method according to a third embodiment of the present invention will be described with reference to FIG. In the third embodiment, the thickness of the formed thin film is measured as needed,
Based on the measurement result, the controller 26 controls the power applied to the surrounding electrodes 1a and 1c to make the thickness of the thin film uniform. In this case, the power to be applied to the electrodes 1a and 1c at both ends may be obtained by using the thickness of the thin film when power is simultaneously applied to all the targets 2a to 2c. It is better to measure the film thickness of the thin film when discharged in step 1 and obtain the optimum power for the electrodes 1a and 1c at both ends based on the measured values, so that the control accuracy is improved and more uniform film formation is possible. Becomes
In the third embodiment shown in FIG. 7, a film thickness measuring device 10 for measuring the thickness of a thin film is provided in a film formation region of a vacuum chamber or adjacent to or close to a film formation region. Information on the measurement result measured by the measuring device 10 is input to the control device 26 and can be used for controlling the power or the power application time. In this case, it is desirable that the measuring device 10 can measure the thickness of the thin film on the entire surface of the substrate 5, but as shown in FIG.
Is installed, if only one axis in the arrangement direction of the targets 2a to 2c can be measured, the power applied to the electrodes 1a and 1c at both ends can be obtained based on the measurement. In this case, the measurement device 10 may not move, and the thickness of the thin film formed on the substrate 5 may be measured when the sputtering device transports the substrate 5. If an optical measuring device is used as the measuring device 10, it can be easily realized.

Next, the results of actual film formation will be described. In this example, three targets of 150 mm × 650 mm were used to form a film on a substrate of 320 mm × 400 mm. The distance between the target and the substrate was 103 mm. The main film forming conditions are shown below. The deposition pressure is 7 mTorr
The gas flow rates of r and Ar gas are 40 sccm, and the deposition power is 4
kW × 3 units. FIG. 8 shows the distribution of the film thickness in the case where the film formation is performed with the electric power applied to the electrodes 1a to 1c of each of the targets 2a to 2c being equalized. FIG.
In FIG. 2, the thickness of the thin film at both ends of the substrate is slightly reduced as shown in FIG. By comparing this film thickness distribution with a simulation, the electrodes 1a,
When the optimum applied power to 1c is obtained, 4.6 kW (+1
5%), and when film formation was actually performed, the film thickness uniformity was improved as shown in FIG. Thereafter, the power is returned evenly to each of the electrodes 1a to 1c to continue film formation, and the integrated power applied to each of the targets 2a to 2c is reduced to 100 kWh.
When the evaluation was made again, the erosion depth was about 2 mm, and the distribution of the film thickness was as shown in FIG. In FIG. 10, the thickness of the thin film at both ends of the substrate is still thinner than that at the center, but slightly thicker than at the beginning. Again, this film thickness distribution is compared with the simulation, and the electrodes 1a, 1c of the targets 2a, 2c at both ends are checked.
When the optimum applied power to the power supply is calculated, 4.44 kW (+11
%), And when the film was actually formed, the film thickness uniformity of the thin film was improved as shown in FIG. By repeating such operations, the optimal power increase with respect to the integrated power is

[Equation 2] It can be seen that [power increase (%)] = 15−0.04 [integrated power (kWh)].

In this case, the erosion depth is used as a parameter,

[Equation 3] [Power increase (%)] = 15-2 [Erosion depth (mm)] In the third embodiment, the film thickness distribution in the case where film formation is performed by each of the targets alone, or the film thickness distribution in the case where film formation is performed by making the power applied to each target or the power application time uniform is described above. The measurement is performed by the film thickness measuring device 10, and the control device 26 determines the thickness of the electrodes 1 a to 1 c based on the measurement result of the film thickness distribution by the film thickness measuring device 10.
By controlling the power or the difference in power application time between them, the thickness of the film formed on the substrate 5 is made uniform. Here, the control based on the film thickness distribution will be described in more detail. The film thickness distribution measured by the measuring device 10 is stored in a memory in the control device 26 in advance, and the film thickness value of the film on the substrate 5 measured by the measuring device 10 during sputtering and the desired film thickness The difference from the thickness value is determined by the controller 26.
Is calculated by the calculation unit in the table, and based on the calculation result in the calculation unit,
With reference to the film thickness distribution, a power or a power application time to be applied to the electrode to obtain the desired film thickness is obtained by the arithmetic unit, and is controlled by the control device 26 so as to have the value.

According to the third embodiment, in addition to the functions and effects of the first embodiment, the thickness of the formed thin film is monitored as needed, and based on the result, the target 2a of the electrodes 1a and 1c on the end side is obtained. , 2c and the power applied to the target 2b of the other electrode 1b other than the end side can be controlled independently of each other, so that the thin film can be more accurately uniformed. In particular, the thickness of the film formed by a single target was measured, and the results were used.
If the power applied or the power application time to the target 2b other than a, 2c or the end side is determined and controlled, the film thickness can be made more uniform. In each of the above embodiments, the description has been made in such a manner that the film thickness is made uniform mainly by controlling the power. However, the film thickness can be made uniform by controlling the power application time, that is, the film formation time. You can do it too. Also, in the above embodiment, all 3
Although the base electrodes are arranged on a straight line, the present invention is similarly applied when four or more electrodes are used or when the electrodes are arranged not on a straight line but on a grid or concentric circles. Can be.

[Brief description of the drawings]

FIG. 1 is a schematic perspective view of a sputtering apparatus for performing a sputtering method according to a first embodiment of the present invention.

FIG. 2 is a diagram in which the same erosion is arranged at regular intervals, and a film thickness distribution in a case where film formation is performed by uniformly applying power is obtained by simulation.

FIG. 3 is a diagram showing, by simulation, a film thickness distribution in a case where film formation is performed by increasing the power at both ends by 12% in the case of FIG. 2 in the sputtering method of the first embodiment.

FIG. 4 is a diagram illustrating a film thickness distribution that can occur when film formation is continued to near the life of a target without performing power control from the case of FIG. 3;

FIG. 5 is a diagram showing a film thickness distribution when power control is performed in FIG. 4 to improve film thickness uniformity in the sputtering method of the first embodiment.

FIG. 6 is a schematic perspective view of a sputtering apparatus for performing a sputtering method according to a second embodiment of the present invention.

FIG. 7 is a schematic perspective view of a sputtering apparatus for performing a sputtering method according to a third embodiment of the present invention.

FIG. 8 is a diagram showing the results of a comparative experiment performed for explaining a sputtering method according to a third embodiment of the present invention.

FIG. 9 is a diagram showing the results of an experiment performed based on the sputtering method according to the third embodiment of the present invention.

FIG. 10 is a view showing an experimental result when film formation is continued in the experiment of FIG. 9;

FIG. 11 is a diagram showing the results of an experiment performed based on the sputtering method according to the third embodiment of the present invention.

FIG. 12 is a diagram showing an example of controlling power applied to both electrodes obtained from the experimental results shown in FIGS.

FIG. 13 is a diagram showing a configuration of a conventional general sputtering apparatus.

FIG. 14 is a diagram showing a relationship among a target, a magnet, erosion, and a film thickness distribution in a conventional general sputtering apparatus.

FIG. 15 is a diagram showing a configuration of a stationary facing type sputtering apparatus of a magnet slide type.

FIG. 16 is a diagram showing a state in which a film thickness distribution by a single target changes as erosion progresses.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Electrode 1a, 1b, 1c Divided electrode 2 Target 2a, 2b, 2c Divided target 3 Power supply device 3a, 3b, 3c Power supply independently installed in each electrode 4 Substrate holder 5 Substrate 6 Gas introduction part 7 Exhaust device Reference Signs List 8 Non-contact shape measuring device 9 Shielding plate 10 Film thickness measuring device 11 Magnet 12 Vacuum chamber 13 Thin film adhered on substrate 14 Magnetic field lines 15 Plasma 16 Magnet driving mechanism 26 Control device

Claims (8)

[Claims] A substrate (5) is held by a substrate support (4) in a vacuum chamber (12) having a gas supply and exhaust function, and is electrically insulated from each other in a plane facing the substrate. In a sputtering method in which a target (2a, 2b, 2c) is arranged on three or more electrode plates (1a, 1b, 1c) and the substrate is formed in a state where the substrate is stationary with respect to the target, an end of the electrode is formed. Power or power applied to the electrodes (1a, 1c) disposed on the side of the electrode during sputtering, between all or at least one of the electrodes (1a, 1c) and the electrode (1b) other than the end-side electrode. A sputtering method, wherein the time is controlled to be different. 2. The method according to claim 1, wherein the depth of the deepest portion of the erosion region on the target is measured, and the power or the difference in the power application time between the electrodes is controlled based on the measurement result.
The sputtering method according to 1. 3. The sputtering method according to claim 2, wherein the depth of the erosion region on the target is measured by a contact type or non-contact type surface shape measuring device. 4. A film thickness distribution when the film is formed by each of the above targets alone, or a film thickness distribution when the film is formed by making the power applied to each target or the power application time uniform, and The sputtering method according to claim 1, wherein a difference in power or a power application time between the electrodes is controlled based on the measurement result. 5. The sputtering method according to claim 4, wherein the thickness of the film formed on the substrate is measured by a film thickness measuring means. 6. A substrate (5) is attached to a target (2a, 2b,
In a sputtering apparatus for forming a film in a stationary state with respect to 2c), a vacuum chamber (12) having a gas supply and exhaust function, a substrate supporter (4) for holding the substrate, and the target are each: And three or more electrodes (1) arranged in a plane facing the substrate.
a, 1b, 1c) and a power source (3) for independently applying power to the electrodes.
a, 3b, 3c) and the electrodes (1a, 1c) of the above-mentioned electrodes arranged on the end side
Between all or at least one of the electrodes and the electrode (1b) other than the end-side electrode during sputtering,
A sputtering apparatus, comprising: a control device (26) for controlling the power supply so as to vary the power applied to the electrode or the power application time. 7. A contact type or non-contact type surface shape measuring device (8) for measuring a depth of a deepest portion of an erosion region on the target, wherein the control device is configured to control the depth by the measuring device. 7. The method according to claim 6, wherein the control unit controls the power or the difference in power application time between the electrodes based on the measurement result.
3. The sputtering apparatus according to 1. 8. A film for measuring a film thickness distribution when the film is formed by each of the targets alone, or a film thickness distribution when the film is formed by making the power applied to each target or the power application time uniform. The apparatus further comprising a thickness measuring device (10), wherein the control device controls a power or a difference in power application time between the electrodes based on a result of the measurement of the film thickness distribution by the film thickness measuring device. 7. The sputtering apparatus according to 6.