JPH11172427A - Film forming device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a film forming device capable of easily preventing foreign matters from being mixed into a coating film on a substrate to be treated. SOLUTION: This film forming device is provided with a target 5 to be sputtered under the reduced pressure, a power source 4 applying voltage to this target 5 and a substrate placing stand 9 on which the substrate 8 to be treated is placed, a passing sheet 7 having an opening 7a through which sputtered particles 6 advancing toward the substrate 8 from the target 5 are interposed between the target 5 and the substrate placing stand 9, the passing sheet 7 is provided with a heat generating means 15, and this heat generating means 15 is controlled by a control means 17 for controlling the heating state of the passing sheet 7 based on the electric power feeding state of the power source 4 to the target 5. Moreover, it is possible that the passing sheet 7 is provided with a temp. detecting means transmitting the heating state of the passing sheet 7 to the control means 17.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a film forming apparatus used in a semiconductor manufacturing process.

[0002]

2. Description of the Related Art When a semiconductor substrate having a stepped portion such as a hole or a groove is formed after adopting a conventionally well-known general sputtering method, it is avoided that the film coverage of the stepped portion is deteriorated. In recent years, a passing plate (hereinafter, referred to as a susceptor) is provided between a target to be sputtered and a substrate mounting table (hereinafter, referred to as a susceptor) on which a semiconductor substrate to be processed (hereinafter, referred to as a substrate to be processed) is mounted. A sputtering method (hereinafter, referred to as a collimator) capable of improving the film coverage of a step portion by increasing the directivity of sputter particles with the collimator.
(Referred to as collimation sputtering).

In such a collimation sputtering method, a so-called collimation sputtering apparatus, which is configured so as to show a state immediately after start of use in FIG. 4 and to show a state after long use in FIG. 5, is used. 4 and 5, reference numeral 1 is a vacuum chamber, 2 is a process gas inlet, 3 is a vacuum pump, 4 is a DC power supply, 5 is a target, 6 is sputtered particles, and 7 is sputtered particles. A collimator, 8 is a substrate to be processed, and 9 is a susceptor. In this case, the collimator 7 has an opening 7a for passing the sputtered particles 6 which travel straight from the target 5 toward the substrate 8 to be processed. Reference numeral 10 in FIG. 5 indicates a coating film formed on the substrate 8 to be processed, and reference numeral 11 indicates an adhered film made of sputtered particles 6 adhered and deposited on the collimator 7.

That is, in this film forming apparatus, the substrate 8 to be processed is positioned and placed on the susceptor 9, and the process gas is exhausted from the vacuum chamber 1 by the vacuum pump 3, while the process gas is introduced from the process gas inlet 2. Introducing a gas into the vacuum chamber 1 is performed. When a negative voltage is applied from the DC power supply 4 to the target 5,
A glow discharge is generated in the decompressed vacuum chamber 1 and the target 5
Will release sputtered particles 6.

[0005] Among the sputtered particles 6 emitted from the target 5, the sputtered particles 6 that travel straight in the vertical direction toward the substrate 8 to be processed pass through the opening 7 a of the collimator 7 and then pass through the opening 8 a of the collimator 7. On the other hand, the sputtered particles 6 proceeding in an oblique direction that is not directed to the substrate 8 to be processed are captured by the collimator 7 to become the adhered film 11, and are deposited on the substrate 8. Will not reach. Therefore, when this film forming apparatus is used, only the sputtered particles 6 that have proceeded straight toward the processing target substrate 8 are deposited and the coating film 10 is formed, and as a result, the film at the stepped portion of the processing target substrate 8 is formed. The coverage is improved.

[0006]

In the conventional film forming apparatus, the operation state of forming the coating film 10 on the substrate 8 and the operation of loading the substrate 8 into the vacuum chamber 1 are described. Alternatively, there is an operation state in which the substrate 8 to be processed is carried out from the vacuum chamber 1, and in the operation state in which the coating film 10 is formed, that is, in a so-called discharging step, a large amount of sputtered particles 6 having high kinetic energy are captured. While the temperature of the collimator 7 continues to rise, the temperature of the collimator 7 decreases due to heat radiation or heat conduction in an operation state of loading or unloading the substrate 8 to be processed, that is, a process during wafer transfer.

However, since the coefficient of thermal expansion of the material of the collimator 7 and the coefficient of thermal expansion of the adhered film 11 composed of sputtered particles 6 are generally different from each other,
The adhesion film 11 is formed with a portion where a local stress due to the temperature rise and the temperature fall acts. When the temperature rise and the temperature fall are repeated, the stressed portion is broken by fatigue and peels off from the collimator 7, and the peeled pieces of the adhesion film 11 fall on the surface of the substrate 8 to be processed. As a result, a foreign substance in the coating film 10 may be formed.

The present invention has been made in view of such inconvenience, and it is an object of the present invention to provide a film forming apparatus capable of easily preventing foreign matter from entering a coating film on a substrate to be processed. I have.

[0009]

According to a first aspect of the present invention, there is provided a film forming apparatus comprising: a target to be sputtered under reduced pressure; a power supply for applying a voltage to the target; and a susceptor on which a substrate to be processed is mounted. And a collimator having an opening through which sputtered particles that travel straight from the target toward the substrate to be processed pass is interposed between the target and the susceptor. The heating means is controlled by control means for controlling the heating state of the collimator based on the voltage application state of the power supply to the target. According to this configuration, since the heating state of the collimator is controlled by the heating means based on the voltage application state of the power supply to the target, the collimator can be maintained at a substantially constant temperature regardless of the operation state of the film forming apparatus. It is possible to prevent local stress from acting on the adhered film of the collimator.

Further, the collimator provided in the film forming apparatus according to the second aspect of the present invention is provided with a heat detecting means and a temperature detecting means, and the temperature detecting means transmits a heating state of the collimator to the control means. It has become something. According to this configuration, the control unit controls the heating unit in consideration of the heating state of the collimator itself.

[0011]

Embodiments of the present invention will be described below with reference to the drawings.

FIG. 1 is an explanatory diagram showing a schematic configuration of a film forming apparatus according to the present embodiment, and FIG. 2 is an explanatory diagram illustrating a temperature change state of a collimator in the present embodiment and a conventional embodiment. Indicates a state after a long time use of the film forming apparatus. The film forming apparatus according to the present embodiment is referred to as a collimation sputtering apparatus by being used when performing film formation after employing the collimation sputtering method, and the overall configuration of the film forming apparatus is as follows. Since there is basically no difference from the related art, in FIG. 1, the same reference numerals are given to the same or corresponding parts and portions as those in FIGS. 4 and 5 according to the related art, and the detailed description thereof will be omitted.

FIG. 1 shows a film forming apparatus according to this embodiment.
As shown by a target, a target sputtered under reduced pressure, that is, a target 5 whose surface is made of titanium, and an output of applying a negative voltage to this target 5 is 12 k
And a susceptor 9 on which a substrate to be processed 8 having a stepped portion such as a hole or a groove is positioned and placed, and between the target 5 and the susceptor 9. Is released from the target 5 and the target substrate 8
Opening 7 through which sputtered particles 6 traveling straight toward
An aluminum collimator 7 having a is interposed. In FIG. 1, reference numeral 10 denotes a coating film formed on the substrate 8 to be processed, and reference numeral 11 denotes an adhered film composed of sputtered particles 6 adhered and deposited on the collimator 7.

At this time, the collimator 7 is provided with a heat generating means 15 using a nichrome wire or the like.
The heat generating means 15 is fixed at a predetermined position on the inner wall of the vacuum chamber 1 via a heat insulating material 16. The heating means 15 has a maximum of 5 k.
Heat is generated by power supply of about W. Furthermore, the film forming apparatus according to the present embodiment includes a control unit 17 which is a microcomputer for controlling a heating state of the collimator 7 based on a voltage application state of the DC power supply 4 to the target 5. In addition, the amount of heat generated by the heat generating means 15 provided in the collimator 7 is controlled by the control means 17 in consideration of the voltage application state of the DC power supply 4.

Next, the operation and operation of the film forming apparatus according to the present embodiment will be described with reference to FIG. 2, which illustrates a temperature change state of the collimator. The solid line in FIG. 2 shows the temperature change state of the collimator provided in the film forming apparatus according to the present embodiment, while the broken line in FIG. 2 shows the temperature change state of the collimator provided in the conventional film forming apparatus. Is shown.

In the film forming apparatus according to the present embodiment, the substrate 8 to be processed is positioned and placed on the susceptor 9, and the process gas is exhausted from the vacuum chamber 1 by the vacuum pump 3. The process gas is introduced from the inlet 2 into the vacuum chamber 1. And
Such a process during wafer transfer, that is, the target 5
In the step of loading the substrate 8 into the vacuum chamber 1 prior to applying a negative voltage from the DC power supply 4, the controller 17 controls the collimator 7 so that the temperature of the collimator 7 itself becomes about 450 ° C. Heating means 1 based on instructions
The collimator 7 is preliminarily heated in accordance with the heat generation of the collimator 5. Note that heating the collimator 7 is the same as when the substrate 8 is carried out from the vacuum chamber 1.

Thereafter, when a negative voltage is applied to the target 5 from the DC power supply 4, glow discharge occurs in the reduced pressure vacuum chamber 1, and sputter particles 6 are released from the target 5 by the sputtering phenomenon. Will be. Then, of the sputtered particles 6 emitted from the target 5 in the process during the discharge, the sputtered particles 6 that travel straight along the vertical direction toward the substrate 8 to be processed pass through the opening 7 a of the collimator 7 and are then coated. While being deposited on the processing substrate 8 to form the coating film 10, sputtered particles 6 traveling in an oblique direction that does not go to the processing target substrate 8 are captured by the collimator 7 and become the adhesion film 11.

Therefore, in this discharging step, the temperature rises in accordance with the fact that the DC power source 4 is applying a negative voltage to the target 5 and the sputtered particles 6 are continuously captured. The amount of heat generated by the heating means 15 heating the collimator 7 is controlled by the control means 17 so that the temperature of the collimator 7 to be heated is about 500 ° C. The optimum value for suppressing the amount of heat generated by the heat generating means 15 will be described later. When the calorific value of the heating means 15 is suppressed, the collimator 7 is not heated much as compared with the case where the wafer is being conveyed, despite the fact that the film forming apparatus is discharging, and FIG. As shown by the solid line, the collimator 7 is maintained at a substantially constant temperature in the range of about 450 ° C. to about 500 ° C.

That is, when the film forming apparatus according to this embodiment is used, the temperature difference is higher than when the conventional film forming apparatus shown by the broken line in FIG. 2 is used. Collimator 7 with almost constant temperature
Is maintained. Therefore, the local stress caused by the repetition of the temperature rise and the temperature fall that cannot be avoided when the film forming apparatus according to the conventional embodiment is used is reduced by the collimator 7 in the film forming apparatus according to the present embodiment.
Does not act on the adhered film 11, and peeling of the adhered film 11 from the collimator 7 is significantly suppressed. As a result, it is difficult for the film forming apparatus according to the present embodiment to cause the strips of the adhered film 11 to fall on the surface of the substrate 8 to be processed and become foreign matters in the coating film 10. .

The optimum value for suppressing the amount of heat generated by the heat generating means 15 during the discharging process is determined by the amount of heat supplied to the collimator 7 by the sputtered particles 6, and the amount of heat supplied to the collimator 7 at this time is determined by the target. Although it depends on the power supplied to the DC power supply 5 and the structure of the film forming apparatus, in most cases, the DC power supply 4
Is in the range of 10% to 40% of the power supplied to the power supply. Therefore, the power supplied to the target 5 is represented by P, and the optimal value for suppressing the amount of heat generated by the heat generating means 15 is represented by Q.
When the relation between P and Q is 0.1 P ≦ Q ≦ 0.
In this embodiment, the power is approximately 30% of the power of 12 kW supplied to the target 5, that is, the power of approximately 3.6 kW is reduced from the power supplied to the heating unit 15. Is done.

Further, in the film forming apparatus according to the present embodiment, the collimator 7 is provided with the heat generating means 15,
In addition, the heat generating means 15 is controlled by the control means 17, but is not limited to such a configuration. The film forming apparatus has a modified example as shown in FIG. May be used. That is, FIG. 3 is an explanatory diagram showing a modified configuration of the film forming apparatus according to the present embodiment, and shows a state after a long time use of the film forming apparatus. In FIG. 3, the same or corresponding parts and portions as those in FIG. 1 are denoted by the same reference numerals, and detailed description thereof will be omitted.

That is, in the film forming apparatus according to this modification, not only the heat generating means 15 and the control means 17 but also the temperature detecting means 18 using an alumel-chromel wire or the like are provided for the collimator 7. In this case, the temperature detecting means 18 is supplied with heat by the sputtered particles 6 and transmits the heating state of the collimator 7 itself heated by the heat generating means 15 to the control means 17 in a feedback manner. It has become something. Therefore, the control means 17 which is a microcomputer determines the amount of heat generated by the heating means 15 in consideration of not only the voltage application state of the DC power supply 4 for applying a voltage to the target 5 but also the heating state of the collimator 7 itself. When such a modified configuration is adopted, thermal characteristics such as heat capacity, thermal conductivity, and thermal emissivity of the collimator 7 may change with the deposition of the adhesion film 11. Even so, the collimator 7 can be maintained at a substantially constant temperature.

[0023]

As described above, according to the first aspect of the present invention,
In the film forming apparatus according to the above, a heating means is provided in a collimator interposed between the target and the susceptor, and the heating means controls a heating state of the collimator based on a power supply state of a power supply to the target. Therefore, the collimator can be maintained at a substantially constant temperature regardless of whether the film forming apparatus is operating during discharge or during wafer transfer, thereby increasing the temperature and increasing the temperature. It is possible to prevent a local stress due to the repeated descending from acting on the adhered film of the collimator. Therefore, when the film forming apparatus having such a configuration is used, local stress does not act on the adhered film of the collimator, and the adhered film is hardly peeled off from the collimator. The effect is obtained that the piece can easily be prevented from falling on the surface of the substrate to be treated and becoming a foreign substance.

In the film forming apparatus according to a second aspect of the present invention, the collimator is provided with temperature detecting means together with the heat generating means, and the temperature detecting means controls the heating state of the collimator with respect to the control means. To communicate. Therefore, when using this film forming apparatus,
As a result of the control means controlling the heat generating means in consideration of the heating state of the collimator itself, the effect is obtained that the collimator can be maintained at a more constant temperature.

[Brief description of the drawings]

FIG. 1 is an explanatory diagram illustrating a schematic configuration of a film forming apparatus according to an embodiment, and shows a state after a long-time use of the film forming apparatus.

FIG. 2 is an explanatory diagram exemplifying a temperature change state of a collimator in the present embodiment and a conventional embodiment.

FIG. 3 is an explanatory view showing a configuration of a modified example of the film forming apparatus according to the present embodiment, and this figure shows a state after a long time use of the film forming apparatus.

FIG. 4 is an explanatory view showing a schematic configuration of a film forming apparatus according to a conventional mode, and this figure shows a state immediately after the use of the film forming apparatus is started.

FIG. 5 is an explanatory diagram showing a schematic configuration of a film forming apparatus according to a conventional embodiment, and shows a state after a long time use of the film forming apparatus.

[Explanation of symbols]

 Reference Signs List 4 DC power supply (power supply) 5 Target 6 Sputtered particle 7 Collimator (passing plate) 7a Opening 8 Substrate to be processed 9 Susceptor (substrate mounting table) 15 Heat generation means 17 Control means 18 Temperature detection means

Claims (2)

[Claims] 1. A target to be sputtered under reduced pressure, a power supply for applying a voltage to the target, and a substrate mounting table on which a substrate to be processed is mounted, wherein a target is mounted between the target and the substrate mounting table. Is a film forming apparatus in which a passing plate having an opening through which sputter particles that travel straight from the target toward the substrate to be processed pass is interposed, wherein the passing plate is provided with a heating means, The film forming apparatus is controlled by control means for controlling a heating state of the passage plate based on a voltage application state of a power supply to the target. 2. The film forming apparatus according to claim 1, wherein the passing plate is provided with a temperature detecting means, and the temperature detecting means transmits a heating state of the passing plate to the control means. A film forming apparatus, characterized in that: