JPH10158832A - Collimate sputtering system - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a collimate sputtering system in which the frequency of replacement of collimaters is made as low as possible for higher productivity. SOLUTION: This device has a temp. controlling means holding the temp. of a collimater 8 passing only the ones flying in a direction approximately vertical to a substrate 50 among sputtering particles from a target 2 to a certain one. This temp. controlling means is composed of a heater 81 heating the collimator 8, a temp. measuring apparatus 82 and a controller 83 controlling the heater 81 in accordance with the measured value from the temp. measuring apparatus 82 and holds the temp. of the collimater 8 to the same certain temp. not only in the process of the driving of the device but also in the states of the idling or stopping of the device.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a sputtering apparatus for forming a predetermined thin film on a surface of a substrate by sputtering, and more particularly, to a sputtering apparatus provided with a collimator for increasing the number of sputtered particles which are perpendicularly incident on the substrate. The present invention relates to a collimating sputtering device.

[0002]

2. Description of the Related Art Sputtering apparatuses for forming a predetermined thin film on the surface of a substrate are actively used in the production of LSIs (Large Scale Integrated Circuits), LCDs (Liquid Crystal Displays), information recording disks, and the like. FIG. 10 is a front view showing a schematic diagram of a conventional collimating sputtering device, and FIG. 11 is an explanatory diagram of step coverage characteristics.

[0003] The collimated sputtering apparatus shown in FIG.
A sputtering chamber 1 provided with an exhaust system 11, a target 2 made of a predetermined material disposed at a predetermined position in the sputtering chamber 1, an electrode 3 for generating a sputter discharge for sputtering the target 2, Discharge gas for sputtering discharge is applied to target 2 and substrate 50.
And a substrate holder 5 for arranging the substrate 50 at a predetermined position in the sputtering chamber 1 where the material of the sputtered target 2 reaches. I have.

[0004] There are various technical requirements for such a sputtering apparatus, but in the field of various semiconductor devices whose integration degree is increasing year by year, improvement of the step coverage characteristics is an important issue. The step coverage characteristic is a property of covering a hole, a groove, or a step formed on the surface of the substrate, and a thin film on a bottom of the groove or hole (hereinafter, collectively referred to as a hole) with respect to a thin film deposition amount on the upper surface. This is a concept including a bottom coverage ratio which is a ratio of the amount of deposition. For example,
When a barrier film is formed by sputtering on the surface of a substrate on which holes such as contact holes or through holes are formed, if the bottom coverage is not sufficient and a barrier film having a sufficient thickness is not formed at the bottom of the hole, diffusion between layers will occur. Prevention is not sufficient, and a fatal defect may be given to device performance such as junction leak.

As the degree of integration increases and the wiring becomes finer, the width of the wiring becomes narrower. On the other hand, the wiring structure becomes complicated due to the high performance of the device, and the depth of the hole becomes deeper. Tend to be. That is, the aspect ratio (hole depth / hole opening width) of the hole tends to be higher.

However, in a conventional general sputtering apparatus, film formation in a hole having an aspect ratio of about 1 to 2 is a limit, which is a technical obstacle when an integrated circuit of 16 Mbit or more is manufactured. ing. This is because many sputtered particles obliquely enter the substrate and the amount of sputtered particles that can reach the bottom of the hole is small. As a result, as shown in FIG. 11, film deposition on the bottom of the hole or groove 500 of the substrate 50 is reduced, and the bottom coverage ratio ((b / a) × 100% in FIG. 11) is considerably reduced.

[0007] To improve the step coverage rate,
It is important to increase the number of sputter particles perpendicularly incident on the substrate 50, and a collimated sputtering apparatus shown in FIG. 10 is known to make this possible. In the sputtering apparatus shown in FIG.
The collimator 8 is disposed in the space between the two. The collimator 8 forms a flight path in a direction perpendicular to the surface of the substrate 50, and includes a lattice-like one, a ring-like one obtained by rolling a band-like plate, and a plurality of concentric arrangements. Is adopted.

[0008] Sputtered particles emitted from the target 2 have a distribution of an amount spreading in a cosine curve centering on a direction perpendicular to the substrate 50 based on the cosine law. When the sputtered particles having such a distribution reach the collimator 8, only those flying in a direction substantially perpendicular to the substrate 50 can pass through the collimator 8, so that the sputtered particles reaching the substrate 50 are perpendicular to the substrate 50. In many directions. For this reason, the above-mentioned bottom coverage rate improves.

[0009]

In the above-described collimating sputtering apparatus, sputter particles naturally adhere to the collimator that regulates the flight direction of the sputter particles, and the sputter particles overlap to deposit a thin film. When such a thin film grows to a certain thickness, it peels off due to internal stress of the film and falls. Such a thin film that separates and falls floats as particles in the sputtering chamber and sometimes adheres to the surface of the substrate. Here, the particles are fine particles made of the same material as the target or fine particles made of a compound of the material of the target and a discharge gas.

Particles adhering to the surface of the substrate cause defects such as local abnormal film thickness. Further, in the production of an integrated circuit, disconnection or short circuit between wirings, poor insulation or the like may be caused. For this reason, in the collimated sputtering apparatus, after repeating the film forming process a predetermined number of times, it is necessary to check whether the number of particles generated on the substrate is equal to or less than a manufacturing allowable value. In this checking work, if the number of particles found exceeds the allowable value in manufacturing, it is necessary to replace the collimator with a new one.

In the collimator, a thin film is deposited as the film forming process is repeated, and the cross-sectional area of the flight path becomes smaller. When the cross-sectional area of the flight path becomes smaller than a predetermined value, the collimator is replaced. However, if the number of generated particles exceeds the allowable value as described above, it is necessary to replace the collie meter before the period of normal use. That is,
Collimator replacement frequency increases.

The operation of replacing the collimator is performed by stopping the operation of the apparatus and opening the inside of the sputter chamber to the atmosphere, and also requires cleaning of the sputter chamber after the replacement. It will take a considerable amount of time to restart. Therefore, when such collimator replacement is performed at a high frequency, there is a problem that the productivity of the apparatus is reduced. In other words, it is required to make the interval between the exchange of the collimator and the next exchange of the collimator as long as possible from the viewpoint of improving the productivity.

The invention of the present application has been made to solve such a problem. That is, an object of the present invention is to provide a collimator sputtering apparatus with high productivity by reducing the frequency of collimator replacement as much as possible.

[0014]

In order to solve the above-mentioned problems, an invention according to claim 1 of the present application is directed to a sputter chamber provided with an exhaust system, and a predetermined material disposed at a predetermined position in the sputter chamber. , A target for generating a sputter discharge for sputtering the target, a substrate holder for arranging a substrate on which a film is to be formed in a predetermined position in a sputtering chamber in parallel with the substrate, and a target for sputtering particles emitted from the target. Among them, a collimator sputtering device having a collimator that passes only those that fly in a direction close to the direction perpendicular to the substrate, and a temperature controller that maintains the temperature of the collimator at a constant temperature is provided. Have. According to a second aspect of the present invention, in order to solve the above-mentioned problem, in the configuration of the first aspect, the temperature control means has the same constant value not only during the operation of the device but also during the stop or stop of the device. It has a configuration in which the temperature of the collimator is maintained at the temperature. According to a third aspect of the present invention, in order to solve the above problem, in the configuration of the first or second aspect, the temperature control means reaches a thermal equilibrium by heating by the sputter discharge in a state where the collimator is not heated. It has a configuration in which the temperature of the collimator is maintained at the temperature. Also, in order to solve the above problems,
According to a fourth aspect of the present invention, in the configuration of the first, second or third aspect, the temperature control means has a temperature measuring device for measuring the temperature of the collimator, and maintains the temperature of the collimator at the constant temperature. It is configured to perform sputtering after confirming that the operation is performed by a temperature measuring device.

[0015]

Embodiments of the present invention will be described below. FIG. 1 is a front view schematically showing a main part of a collimator sputtering apparatus according to an embodiment of the present invention, FIG. 2 is a schematic plan view showing the entire structure of the collimator sputtering apparatus shown in FIG. 1, and FIG. FIG. 3 is a schematic plan view showing a configuration of a collimator in the apparatus of FIG. 2 and FIG.

The collimating sputtering apparatus according to the present embodiment
This is a multi-chamber type device as shown in FIG. That is, a transfer chamber 100 having a transfer robot or the like is provided at the center, and a plurality of treatment chambers 101, a sputter chamber 1, a load lock chamber 102, an unload lock chamber 103, and the like are provided around the transfer chamber 100. 100, 101, 102,
103 can be evacuated to a predetermined pressure by a dedicated or shared exhaust system. Then, the transfer robot 110
However, the substrate 50 is taken out of the load lock chamber 102 one by one, sequentially sent to the treatment chamber 101 or the sputter chamber 1 to be processed, and then sent to the unload lock chamber 103 for collection.

The structure of the sputtering chamber 1 will be described. The collimated sputtering apparatus according to the present embodiment is, as shown in FIG. 1, a target 2 made of a predetermined material disposed at a predetermined position in the sputtering chamber 1.
And an electrode 3 for generating a sputter discharge for sputtering the target 2, a substrate holder 5 for disposing a substrate 50 on which a film is to be formed at a predetermined position in the sputtering chamber 1 in parallel with the substrate 50, and a discharge from the target 2. And a collimator 8 for passing only those particles which fly in a direction close to the direction perpendicular to the substrate 50 among the sputtered particles.

First, the sputtering chamber 1 is provided with an exhaust system 1
1 is an airtight container provided with a gate valve (not shown). The evacuation system 11 is provided with a multi-stage vacuum pump such as a combination of a cryopump 111 and a rotary pump 112, so that the inside of the sputtering chamber 1 is 1 × 10 ⁻⁷ Torr.
It is configured to be able to exhaust up to the ultimate pressure.

The target 2 is a circular or square plate-like member formed of a material to be formed into a film. The target 2 is fixed to the front side of the electrode 3 by a method such as screwing. A target shield 35 is provided so as to cover the periphery of the target 2. The target shield 35 is for preventing unnecessary discharge around the target 2 and is provided in a grounded state while covering the periphery of the target 2 at a predetermined narrow interval.

The collimating sputtering apparatus of the present embodiment
This is a kind of flat plate magnetron sputtering apparatus, and a magnetron cathode is used as the electrode 3. That is, the electrode 3 is a pair of magnets 3 disposed behind the target 2.
1 and 32 and a yoke 33 connecting the pair of magnets 31 and 32. The pair of magnets 31 and 32 are permanent magnets for forming a leakage magnetic field closed in front of the target 2, and have a columnar magnet (eg, N pole) 31 at the center.
And a ring-shaped magnet (for example, S-pole) 32 surrounding it with a gap.

A discharge power supply 34 is connected to the electrode 3, and a predetermined negative DC voltage or high frequency is applied to the electrode 3. More specifically, for example, a DC power supply (voltage 750 V, current 20 A) having an output of 15 kW can be used.

As the discharge gas, an inert gas such as argon having a high sputtering rate is used. The gas introducing means 4 for introducing the discharge gas includes a gas introducing pipe 41 connecting the cylinder (not shown) and the sputtering chamber 1, a valve 42 provided in the gas introducing pipe 41, a flow regulator (not shown), and the like. It is mainly composed.

The substrate holder 5 is configured to place the substrate 50 on the upper surface and hold the substrate 50 in parallel with the target 2. A substrate heater 51 for heating the substrate 50 to a predetermined temperature is provided in the substrate holder 5. The substrate heater 51 is, for example, of a resistance heating type, and is configured to heat the substrate 50 to, for example, about 300 ° C. In some cases, a suction electrode for inducing static electricity on the surface to electrostatically attract the substrate 50 may be provided in the substrate holder 5.

The sputter chamber 1 is grounded, and the substrate holder 5 is provided in a short-circuited state with respect to the sputter chamber 1. As another configuration, a predetermined self-bias voltage may be applied to the substrate 50 by insulating the substrate holder 5 from the sputtering chamber 1 and applying a predetermined high-frequency voltage to the substrate holder 5.

Next, the configuration of the collimator 8 will be described with reference to FIGS. As shown in FIGS. 1 and 3, the collimator 8 has a thickness of 1 in this embodiment.
A structure in which circular openings having a diameter of about 10 mm are provided at equal intervals in a titanium plate of about 0 mm is used. The aperture ratio is, for example, about 80%. The distance between the target 2 and the collimator 8 is about 65 mm, and the distance between the collimator 8 and the substrate 50 is about 35 mm.

A major feature of the apparatus according to the present embodiment is that a temperature control means for maintaining the temperature of the collimator 8 at a constant temperature (hereinafter, control temperature) is provided. The temperature control means includes a heater 81 for heating the collimator 8 and a temperature measuring device 82 for measuring the temperature of the heater 81.
And a controller 83 for controlling the heater 81 according to the measurement result of the temperature measuring device 82.

The heater 81 is an annular member provided around the collimator 8. The heater 81 is of a resistance heating type, and has a configuration in which a heating wire made of high-purity carbon or the like is incorporated in an annular member made of a heat conductive material such as aluminum. Specifically, a power of about 1 kW and a current of about 10 A can be used. The inner diameter of the heater 81 is adapted to the outer diameter of the collimator 8, and the heater 81 is connected to the collimator 8 with good thermal contact by a method such as welding, diffusion bonding, or screwing.

The heater 81 is held by a holding rod 84 fixed to the sputtering chamber 1. Holding rod 8
4 are provided at approximately equal intervals. The collimator 8 has a posture parallel to the substrate 50 and the target 2, and is held by a holding rod 84 via a heater 81. In the holding rod 84, a heater 81 is provided.
A power supply line is provided to the sputter chamber 1.
It is connected to a controller 83 provided outside. The signal line of the temperature measuring device 82 also passes through the wall of the sputtering chamber 1 in an airtight manner, and is connected to the controller 83.

The controller 83 includes a power supply section 831 for supplying electric power for heating to the heater 81 and a control section 832 for controlling electric power supplied by the power supply section 831. The control unit 832 has an input unit (not shown) for inputting the set temperature. The signal of the temperature of the heater 81 measured by the temperature measuring device 82 is fed back to the control unit 832 of the controller 83, and the control unit 832 controls the power supply unit 831 so as to reach the input set temperature. I have.

Further, as the temperature measuring device 82, a configuration in which a K-type (chromel-aluminum type) thermocouple is brought into contact with the surface of the heater 81 can be used. Alternatively, a radiation thermometer or the like may be used. The signal from the temperature measuring device 82 is sent to a main control unit (not shown) for controlling the entire apparatus, and after confirming that the temperature of the collimator 8 is maintained at a predetermined control temperature, the apparatus is started. It is configured to operate and perform sputtering.

As shown in FIG. 1, the apparatus of the present embodiment is provided with an anti-adhesion shield 6 for preventing sputter particles from adhering to the inner wall surface of the sputter chamber 1.
The deposition shield 6 is a cylindrical member that surrounds the target 2, the collimator 8, and the substrate holder 5. The deposition-inhibiting shield 6 is made of, for example, aluminum or the like, and is subjected to a surface treatment as necessary to prevent the deposited film from peeling off on its inner surface. Further, the above-described holding rod is provided through an insertion hole provided in the deposition-inhibiting shield 6 and is fixed to the wall of the sputtering chamber 1. An opening for gas introduction, a gas exhaust port, and the like may be provided in the deposition-inhibiting shield 6.

Next, the operation of the apparatus of this embodiment will be described. First, the transfer robot 110 takes out the substrate 50 from the load lock chamber 102 and carries it into the sputtering chamber 1. At this time, a pre-treatment of preheating the substrate 50 or performing sputter cleaning on the surface of the substrate 50 may be performed. In this case, the pre-treatment is performed in the treatment chamber 101 having a configuration necessary for such a treatment. After that, the substrate 50 is carried into the sputtering chamber 1. The substrate 50 carried into the sputtering chamber 1 is placed on the substrate holder 5. Further, the inside of the sputtering chamber 1 is evacuated to about 2 × 10 ⁻⁶ Torr or less in advance. The temperature of the collimator 8 is controlled by temperature control means including a heater 81, and is preliminarily heated to a control temperature of about 200 ° C.

In this state, the gas introducing means 4 operates to introduce a predetermined gas into the sputtering chamber 1 at a predetermined flow rate. Then, the discharge power supply 34 operates to apply a predetermined voltage to the electrode 3. Thereby, the sputtering chamber 1
Is generated, and the target 2 is sputtered. Part of the sputtered material of the target 2 (sputtered particles) reaches the substrate 50 after passing through the collimator 8, and as described above, a film is formed on the substrate 50 with good bottom coverage.

At this time, it is recognized that sputter particles adhere little by little to the collimator 8 and a thin film is deposited with time. However, since the collimator 8 is maintained at a constant temperature by the temperature control means, the deposition is performed. The generation of thermal stress inside the thin film is suppressed. For this reason, the possibility of peeling of the thin film from the collimator 8 due to the thermal stress is reduced, and even if the thin film becomes considerably thicker than in the past, the thin film does not fall off. Therefore, the frequency of replacement of the collimator 8 can be reduced, and in this respect, the device has high productivity.

The collimator 8 is heated not only by the heater 81 but also by plasma formed by sputter discharge. That is, the collimator is heated by heating by collision of charged particles in the plasma, radiant heating by plasma emission, and the like. Therefore, the control unit 80 that performs feedback control based on the signal from the temperature measuring device temperature 82 controls the heater 81 so that the control temperature is maintained by the heat from the heater 81 and the heat from the plasma. That is, if the heat from the plasma decreases, the heating amount of the heater 81 increases, and if the heat from the plasma increases, the heating amount of the heater 81 decreases.

It is preferable that the temperature control by the temperature control means be performed at all times not only during the stoppage of the apparatus during each film forming process but also during the stoppage of the apparatus. If the collimator 8 is constantly heated, the sputtering can be started immediately after the substrate 50 is loaded, which is favorable in terms of productivity. As another configuration, the temperature control means may be operated after the substrate 50 is carried in, and sputtering may be performed after the collimator 8 is maintained at a predetermined control temperature. Alternatively, when the operation of the apparatus is started, the temperature control means of the collimator 8 may be operated first, and the temperature control means may be always operated during the operation of the apparatus. These configurations have advantages in energy saving.

The “stop of the apparatus” is a period from the end of one film forming process to the next film forming process when the film forming process is repeated. This is a period during which the apparatus itself stops operating, such as during maintenance or when the entire production line is stopped.

[0038]

Next, a description will be given of an example in which a film forming process is performed using the apparatus of the above embodiment. When the above-described apparatus is used, for example, a film forming process can be performed under the following conditions.

FIGS. 4 to 9 show the results of experiments in which the effects of the apparatus of the present embodiment were confirmed, and show the results of experiments in which the apparatus was operated under the conditions of the above embodiment. 4 to 6 show the results of repeating the film forming process without operating the temperature control means of the collimator 8, and FIGS. 7 to 9 show the film formation while operating the temperature control means of the collimator 8. It is a figure of the result of having repeated processing. And
4 and 7 are diagrams showing the relationship between the number of times of the film forming process and the temperature of the collimator 8, and FIGS. 5 and 8 show the relationship between the number of times of the film forming process and the number of particles on the substrate 50. FIG. FIGS. 6 and 9 are diagrams showing the relationship between the number of times of the film forming process and the sheet resistance value of the film.

The method of measuring particles was as follows. Every time the film forming process is repeated 50 times, a silicon wafer (diameter 6 inches) for particle measurement is carried into the sputtering chamber 1, and the film is formed under the same conditions as those in the above embodiment and without operating only the power supply. As a condition not to perform, the substrate was held on the substrate holder 5 for the same time as the film formation time. After that, the silicon wafer is taken out of the device and TEN
The number of particles on the silicon wafer was measured using a surfscan 5500 laser particle measuring device manufactured by COR. In addition, only the number of particles having a particle size of 0.3 μm or more was counted.

First, as shown in FIG.
When the temperature control means is not operated, the temperature of the collimator 8 immediately after the start of the operation of the apparatus is as low as about 30 ° C., and gradually rises as the number of treatments increases. After about 25 times, the temperature of the collimator 8 reaches equilibrium and stabilizes at a value of about 180 ° C. This indicates a situation in which the film is heated by the plasma formed by the sputter discharge and gradually rises in temperature while the film forming process is repeated.

The temperature data shown in FIG. 4 is obtained by plotting and connecting the temperatures of the collimator 8 during the film forming process. In the pause period of the processing between each film forming process, the collimator 8 gradually dissipates heat and the temperature decreases. Therefore, in actuality, the temperature changes as shown by a dotted line in FIG. Expected to be.

Further, as shown in FIG.
When the temperature control means is not operated, the number of particles on one silicon wafer was initially small at about four, but increased as the number of treatments increased.
At the end of the processing, the number has reached 50 or more. Then, after 300 times, the number of particles rapidly increased, and reached about 200 when the processing was performed 500 times.

It is considered that this is because, as described above, the sputtered particles adhering to the collimator 8 form a thin film deposited under the condition where the thermal stress is relatively high. That is, during a period in which the number of processes after the start of the operation of the apparatus is small, the temperature of the collimator 8 is low as shown in FIG. 4, and then gradually rises. Therefore, it is assumed that the thin film deposited on the collimator 8 during this period has relatively large internal stress due to heat. It is considered that the thin film deposited with a large internal stress is easily peeled off, and the processing is repeated about 150 times, so that a large amount of particles fall off from the collimator 8 to generate many particles. In the manufacture of an integrated circuit such as a 16 MDRAM, the number of particles on the substrate 50 is set to 50 or less. Therefore, when the temperature control means is not used, the collimator 8 is already replaced when the processing is completed 200 times. A need will arise.

Further, as shown in FIG.
When the temperature control means is not operated, the sheet resistance value of the substrate 50 on which the film formation processing is performed up to about seven times after the operation of the apparatus is started is higher than that after the processing. Specifically, the sheet resistance of the thin film produced on days 1, 2 and 3 times are beyond 11μΩ / mm ^2, up to 4 subsequent 25th remained up and down the 10.6μΩ / mm ² near I have.

The variation in the sheet resistance value is represented by Δ (maximum value−
When calculated according to the formula of (minimum value) / (maximum value + minimum value)｝ × 100 (%), the maximum value was 11.8 μΩ / mm ² and the minimum value was 10.4 μΩ / mm ² , so ± 6.31
%Met. In the production of integrated circuits such as 16MDRAM,
The dispersion of the sheet resistance value needs to be normally suppressed to within 5% in the above calculation formula. Therefore, when the temperature control means is not used, this condition is not satisfied and it is understood that the temperature control means is inappropriate.

The cause of the variation in the sheet resistance value when such a temperature control means is not used is considered as follows. As shown in FIG.
The member disposed between the sputtering chamber 1 and the substrate 50, and is a member relatively close to the substrate 50 among members in the sputtering chamber 1. In this case, since the collimator 8 is heated by the plasma as described above, the substrate 50 is heated not only by the direct heating by the plasma but also by the radiant heat from the collimator 8. Therefore, the temperature of the substrate 50 is affected by the temperature of the collimator 8,
Is considered to change when the temperature of the substrate 50 changes.

It is considered that the variation in the sheet resistance value while the number of times of processing shown in FIG. 6 is small is caused by this point. That is, while the number of times of processing is small, the temperature of the collimator 8 is lower than that in the thermal equilibrium state, and therefore, it is considered that the temperature of the substrate 50 during processing is slightly lower. Then, the sheet resistance value of the thin film prepared in this experiment is sensitive to the film formation temperature, and it is determined that the above-mentioned variation occurs due to this.

Next, when the temperature control means of the collimator 8 is used, as shown in FIG. 7, the temperature of the collimator 8 is maintained at the control temperature (200 ° C.) from the beginning of the operation of the apparatus, and becomes stable. ing. Then, as shown in FIG. 8, the number of particles found on the silicon wafer is 500
It can be seen that the number is reduced to 50 / sheet or less until the processing is repeated up to about twice, and that the generation of particles is small and the manufacturing tolerance is satisfied. Further, as shown in FIG. 9, the sheet resistance value of the formed thin film is substantially uniform, and 10.4 μΩ in the first to 25th processes.
/ Mm ² to 11.0 μΩ / mm ² . The variation of the sheet resistance calculated by the above formula is 2.80%, and it can be seen that the variation of the sheet resistance is also equal to or less than the allowable value in manufacturing.

It is clear that such a result is caused by maintaining the collimator 8 at a constant temperature by the temperature control means. In other words, since the temperature of the collimator 8 is constant, the internal stress due to heat in the thin film deposited on the collimator 8 is small, and it is suppressed that the collimator 8 peels and falls until it grows into a considerably thick thin film. Further, since the temperature of the collimator 8 is constant, the radiant heat received by the substrate 50 from the collimator 8 is also constant, so that the film quality such as the sheet resistance value is also constant.

It is presumed that the stabilization of the sheet resistance value by heating the collimator 8 in advance may also be caused by the following points. That is, for example, when the operation of the apparatus is started with a new collimator 8 attached and the temperature control means is not used, a large amount of occluded gas is released (degassed) from the collimator 8 as the temperature rises. Occurs. It is presumed that the gas released at this time adheres to the substrate 50 and is taken into the thin film, which causes a variation in film quality such as a sheet resistance value. If the collimator 8 is pre-heated and maintained at a constant temperature by using the temperature control means, the increased gas of the collimator 8 is sufficiently released, and a state in which a very small amount of gas is stably released is maintained. Is done. As a result, variations in film quality due to degassing are also suppressed.

The apparatus of the present embodiment is a single-wafer type, that is, a substrate 50.
4 to 9 are equal to the number of processed films, but in an embodiment of the present invention, a batch process, that is, a plurality of substrates 50 is processed simultaneously. In this case, the “number of times of the film forming process” is smaller than the number of processed films.

In the above description, when the temperature control means is not used, the thermal equilibrium temperature of the collimator 8 is 180 ° C.
Although the control temperature is 200 ° C., that is, the collimator 8 is heated to a constant temperature equal to or higher than the thermal equilibrium temperature, the collimator 8 may be heated to the same temperature as the thermal equilibrium temperature. In this case, the heat supply from the heater 81 decreases as the heat supply from the plasma increases after the start of the film forming process, and when the state where the thermal equilibrium is maintained only by the heat from the plasma is reached, the heater 81 directly Is not supplied with heat.

[0054]

As described above, according to the first aspect of the present invention, since the temperature of the collimator is maintained at the control temperature, the thermal stress in the thin film deposited on the collimator is suppressed, and The generation of particles due to the separation and falling of the particles is suppressed. For this reason, the frequency of replacement of the collimator can be reduced, and a collimator sputtering apparatus with high productivity can be obtained.
Further, since the thermal radiation of the collimator to the substrate is constant, the temperature of the substrate is always stable, and the variation in the film quality can be suppressed low. According to the second aspect of the present invention, in addition to the above-described effects, the sputtering can be started immediately after the substrate is loaded into the sputtering chamber, so that the apparatus is excellent in productivity. According to the third aspect of the present invention, in addition to the above effects, when the collimator reaches thermal equilibrium only by heat from the plasma, it is not necessary to apply heat from the temperature control means. Device. According to the invention of claim 4, in addition to the above-described effects, it is confirmed whether or not the temperature of the collimator is maintained at the control temperature when performing the sputtering, so that the effect of suppressing the generation of particles and the like is reliably obtained. be able to.

[Brief description of the drawings]

FIG. 1 is a front view schematically showing a main part of a collimated sputtering apparatus according to an embodiment of the present invention.

FIG. 2 is a schematic plan view showing the entire structure of the collimator sputtering apparatus of FIG.

FIG. 3 is a schematic plan view showing a configuration of a collimator in the apparatus shown in FIGS. 1 and 2.

FIG. 4 is a diagram showing the results of an experiment for confirming the effect of the apparatus of the present embodiment, and shows the number of film forming processes and the collimator when the film forming process is repeated without operating the temperature control means of the collimator. It is a figure showing the relation with temperature.

FIG. 5 is a diagram showing the results of an experiment for confirming the effect of the apparatus of the present embodiment, and shows the number of times of film formation processing when the film formation processing is repeated without operating the temperature control means of the collimator, and FIG. 3 is a diagram illustrating a relationship with the number of particles.

FIG. 6 is a view showing the results of an experiment for confirming the effect of the apparatus of the present embodiment, and shows the number of times of film formation processing and the number of film sheets when the film formation processing is repeated without operating the temperature control means of the collimator It is a figure showing the relation with a resistance value.

FIG. 7 is a diagram showing the results of an experiment for confirming the effect of the apparatus of the present embodiment, and shows the number of film formation processes when the film formation process is repeated while operating the temperature control means of the collimator, and It is a figure showing the relation with temperature.

FIG. 8 is a diagram showing the results of an experiment for confirming the effect of the apparatus of the present embodiment. FIG. 3 is a diagram illustrating a relationship with the number of particles.

FIG. 9 is a diagram showing the results of an experiment for confirming the effect of the apparatus of the present embodiment, and shows the number of film formation processes and the number of film sheets when the film formation process is repeated while operating the temperature control means of the collimator. It is a figure showing the relation with a resistance value.

FIG. 10 is a front view schematically showing a conventional collimating sputtering apparatus.

FIG. 11 is an explanatory diagram of a step coverage characteristic.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Sputter chamber 11 Exhaust system 2 Target 3 Electrode 4 Gas introduction means 5 Substrate holder 50 Substrate 8 Collimator 81 Heater 82 Temperature measuring device 83 Control part

Claims (4)

[Claims] A sputter chamber having an exhaust system;
A target made of a predetermined material disposed at a predetermined position in the sputtering chamber, an electrode for generating a sputter discharge for sputtering the target, and a substrate on which a film is to be formed are parallel to the target at a predetermined position in the sputtering chamber. A collimator sputtering apparatus comprising a substrate holder arranged at a position and a collimator for passing only those sputtered particles emitted from the target that fly in a direction substantially perpendicular to the substrate. A collimated sputtering device comprising a temperature control means for maintaining the temperature. 2. The temperature control device according to claim 1, wherein the temperature of the collimator is maintained at the same constant value not only during the operation of the apparatus but also during the stop or stop of the apparatus. 2. The collimating sputtering apparatus according to 1. 3. The collimator according to claim 1, wherein the temperature control means maintains the collimator at a temperature at which the collimator reaches thermal equilibrium by heating by sputter discharge in a state where the collimator is not heated. 3. The collimated sputtering apparatus according to 2. 4. The temperature control means has a temperature measuring device for measuring the temperature of the collimator, and after confirming by the temperature measuring device that the temperature of the collimator is maintained at the constant temperature, the temperature is controlled by sputtering. 4. The collimating sputtering apparatus according to claim 1, wherein the collimating sputtering apparatus is configured to perform the following.