JP2010147201A - Substrate processing device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a substrate processing device capable of preventing reaction byproducts from attaching to a wall surface of a reaction chamber. <P>SOLUTION: A first inert gas introduction nozzle 58 is formed in the inside of a reaction chamber 12 so as to let inert gas 56 flow from near the surface 14 of the reaction chamber wall on the side of the gate valve 44 of the reaction chamber 12. An exhaust port 60 is formed on the wall surface of the reaction chamber 12 on the side that counters the first inert gas introduction nozzle 58. During the process operation, the inert gas 56 is supplied from the side surface direction of a susceptor 18 and the gas is changed into laminar flow state so that the inert gas can flow to the side of the exhaust port 60, while preventing the reaction byproducts from attaching to each section of the members in the reaction chamber 12. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a substrate processing apparatus for forming a thin film on a surface of a substrate to be processed and modifying the thin film.

FIG. 1 shows a cross-sectional view of a conventional parallel plate type substrate processing apparatus 10.
The reaction chamber 12 is hermetically configured with a reaction chamber wall 14, and an upper electrode 16 and a susceptor 18 are provided inside the reaction chamber 12 so as to face each other. A reaction gas introduction part 20 is provided above the upper electrode 16, and as shown by arrows, a first reaction gas 22 and a second reaction gas 24 (hereinafter referred to as reaction gases 22, 24) are used as gas shower plates. 26 can be supplied to the reaction chamber 12.

  Further, the upper electrode 16 is insulated from the reaction chamber wall 14 by an insulating block 28, supplies high frequency power output from an oscillator 30 through a matching device 32, and a reaction gas 22 introduced from the reaction gas introduction unit 20 under reduced pressure, 24 is used to generate plasma 34.

  The susceptor 18 is heated by a susceptor heater 36 to heat a substrate to be processed 38 on the susceptor 18.

  An exhaust pipe 40 for exhausting the reaction chamber 12 is provided on the surface of the reaction chamber wall 14 and connected to a pump (not shown) via an exhaust gate valve 42 to exhaust the reaction chamber 12. .

  In addition, a gate valve 44 is provided in a slit provided in a part of the reaction chamber wall 14, and a substrate to be processed is obtained by the cooperation of a wafer pin 48 that is airtight and vertically movable by a bellows 46 and a transfer robot (not shown). 38 can be loaded and unloaded.

Next, the operation of the conventional parallel plate type substrate processing apparatus 10 will be described.
After exhausting the inside of the reaction chamber 12 by the exhaust pipe 40 by an exhaust pump (not shown), the gate valve 44 is opened, and the substrate 38 is transferred onto the susceptor 18 by the cooperation of the wafer pins 48 and the transfer robot (not shown). Thereafter, reaction gases 22 and 24 having a constant flow rate are introduced from the reaction gas introduction unit 20, and the pressure in the reaction chamber 12 is stably maintained at a predetermined value.

  When the high frequency power output from the oscillator 30 is supplied to the upper electrode 16 via the matching unit 32, the plasma 34 is generated in the reaction chamber 12, and the substrate to be processed 38 placed on the susceptor 18 is processed.

For example, when a silicon nitride (SiN) film is formed on the surface of a silicon wafer, the following processing conditions are used, for example. Monosilane _(SiH 4): _500sccm, ammonia _(NH 3): 2000sccm, nitrogen _(N 2): _1000sccm, pressure: 399 Pa, RF power: 1200W (13.56MHz), electrode spacing: 20 mm, a silicon wafer temperature: 350 ° C.. When film formation is performed under these processing conditions, a film formation speed of about 5000 Å / min is obtained.

However, when the silicon nitride film is formed by the conventional parallel plate substrate processing apparatus 10 described above, reaction by-products adhere to the inner surface of the reaction chamber wall 14 of the reaction chamber 12.
These reaction by-products are deposited by a gas phase reaction and a surface reaction on the inner surface of the reaction chamber wall 14 while the reaction gas convects to each part of the reaction chamber 12. The deposition rate varies depending on the temperature, residence time, pressure, and the like of the reaction chamber wall 14.

The reaction by-product deposit gradually becomes thick, eventually peels off and becomes a fine foreign substance that floats during the process, and adheres to the wafer surface, which is the substrate to be processed.
The foreign matter adhering to the wafer causes a decrease in the yield of device production in the semiconductor manufacturing process, and therefore it is necessary to remove the foreign matter before it occurs.

There are two methods for removing reaction by-products: a method in which an active cleaning gas is introduced between processes to perform etching, and a method in which a reaction chamber is opened to clean or scrape parts to which reaction by-products are attached. It is used.
However, since both methods require time, it causes a decrease in productivity of the apparatus.
Not only from the side wall surface side of the reaction chamber, but also from the top and bottom of the reaction chamber wall 14 surface

  As a conventional technique for solving these problems, for example, Patent Document 1 discloses that a light incident window is covered with a gas not related to a photochemical reaction in a photoexcited CVD apparatus to prevent adhesion of a reaction product. Yes. In Patent Document 2, it is disclosed to suppress the adhesion of reaction products to the sample holder and the sample chamber by sandwiching the central reactive gas layer between upper and lower inert gas layers. In Patent Document 3, the inert gas is injected slightly apart from the substrate surface in parallel while supplying the reaction gas in the laser CVD apparatus, so that even if particles are formed in the air, the substrate is blocked by the inert gas. It is disclosed that it is discharged without reaching the surface. Patent Document 4 discloses that an intrusion between the lower surface of the stage and the semiconductor substrate is prevented by blocking the reaction by-product floating on the outer periphery of the stage with an inert gas. Further, in Patent Document 5, by supplying a second gas having a composition different from that of the first gas to the gap between the electrode and the shield electrode, the by-product itself and the by-product in the vicinity of the end on the exhaust port side are generated. Suppressing product deposition is disclosed.

Japanese Patent Laid-Open No. 2-79429 JP-A-5-339734 JP-A-1-251607 JP-A-6-333833 JP 2005-353937 A

  However, there is a portion where gas stagnates in the processing chamber, and the prevention of adhesion of by-products is not sufficient, and it is necessary to frequently clean the parts to which the by-products are attached.

  An object of the present invention is to provide a substrate processing apparatus that suppresses adhesion of reaction by-products to the reaction chamber wall surface in order to reduce the frequency of cleaning the reaction chamber.

  In order to achieve the above object, a substrate processing apparatus according to the present invention includes a processing chamber for processing a substrate, a substrate support for supporting the substrate in the processing chamber, and a substrate support surface of the substrate support. A reactive gas supply system for supplying a reactive gas into the processing chamber, and a plurality of inert gas supply nozzles in the vicinity of the processing chamber wall so that the inert gas is supplied from a direction different from the reactive gas. A substrate processing apparatus having an inert gas supply system provided and a gas exhaust system for exhausting a gas in the processing chamber. Thereby, by-products remaining in the vicinity of the substrate are removed, and no stagnation occurs in the processing chamber, so that all by-products in the processing chamber can be removed.

  Preferably, the substrate processing apparatus causes the inert gas to collide with the inner wall of the processing chamber with the opening of the inert gas supply nozzle directed in the direction opposite to the wafer. Accordingly, the pressure of the inert gas flowing toward the wafer due to the impact on the processing chamber wall can be reduced, and the substrate can be prevented from being exposed to a large amount of the inert gas.

  Preferably, the inert gas supply nozzle is provided so that an inert gas is supplied in parallel to the substrate.

  Suitably, the said substrate processing apparatus provides a shielding board between the said substrate support part and the said reactive gas supply system. This can prevent the inert gas from flowing onto the substrate.

  Preferably, a plasma generator is provided that generates the plasma in the processing chamber by supplying the reaction gas between a pair of opposed plate electrodes and applying high frequency power to at least one plate electrode of the pair of plate electrodes. .

  Preferably, the inner wall of the processing chamber has a round shape without corners.

  Preferably, an inert gas is allowed to flow under the substrate support.

  Preferably, a shielding plate is provided below the substrate support.

  According to the present invention, during the plasma processing of the substrate to be processed, reaction by-products can be prevented from coming into contact with the wall surface in the reaction chamber (processing chamber) and various members in the processing chamber. It is possible to suppress the reaction by-product from adhering to the wall surface and various members in the processing chamber.

  In addition, the frequency of in-situ cleaning and reaction chamber opening maintenance is reduced from 1/5 to 1/10, and the throughput of the apparatus can be improved.

Next, embodiments of the present invention will be described with reference to the drawings.
2 and 3 show a substrate processing apparatus 50 as an embodiment of the present invention. FIG. 3 shows a state where the susceptor 18 provided so as to be movable up and down is lowered. The reaction chamber 12 is hermetically configured with a reaction chamber wall 14, and an upper electrode 16 and a susceptor 18 are provided inside the reaction chamber 12 so as to face each other. A reaction gas introduction unit 20 is provided above the upper electrode 16 so that the reaction gases 22 and 24 can be supplied from the gas shower plate 26 to the reaction chamber 12 as indicated by arrows.

  Further, the upper electrode 16 is insulated from the reaction chamber wall 14 by an insulating block 28, and the high frequency power output from the oscillator 30 is passed through the matching unit 32 via the rotation introducing terminal 54 to the similarly insulated susceptor shaft 52. The plasma 34 is generated by using the reaction gases 22 and 24 that are supplied and introduced from the reaction gas introduction unit 20 under reduced pressure.

  The susceptor 18 is heated by a susceptor heater 36 to heat the substrate to be processed 38 on the susceptor 18 and the susceptor 18 is rotatable. Since the susceptor 18 can rotate, the processing on the substrate to be processed 38 can be performed uniformly.

  An exhaust pipe 40 for exhausting the reaction chamber 12 is provided on the surface of the reaction chamber wall 14 and connected to a pump (not shown) via an exhaust gate valve 42 to exhaust the reaction chamber 12. . In addition, it is preferable that the inner wall of the exhaust pipe 40 has a rounded shape with no corners so that by-products are less likely to accumulate on the inner wall.

  A gate valve 44 is provided in a slit provided in a part of the reaction chamber wall 14, and as shown in FIG. 3, the susceptor 18 is lowered and the substrate 38 is placed on the wafer pins 48, not shown. The transfer robot is configured to carry in / out the substrate to be processed 38.

Further, an inert gas first introduction nozzle 58 is provided inside the reaction chamber 12 so that the inert gas 56 can flow from the vicinity of the surface of the reaction chamber wall 14 on the gate valve 44 side of the reaction chamber 12. That is, the inert gas can flow in a direction different from that of the reactive gas because the reactive gas is located at a different location from the reactive gas inlet 20. An exhaust port 60 is provided in the wall surface of the reaction chamber 12 on the side opposite to the inert gas first introduction nozzle 58, and the inert gas 56 is supplied from the side surface direction of the susceptor 18 during the process execution, and is supplied to the substrate 38. On the other hand, it can be made into a laminar flow so as to flow parallel to the exhaust port 60.
The installation location of the exhaust port 60 is not limited to the above-described configuration, and it is most preferable that the exhaust port 60 be installed at a horizontal position with the inert gas first introduction nozzle 58. Any position may be used as long as adhesion to the wall surface in the reaction chamber and various members in the processing chamber can be suppressed.

  The supply of the inert gas 56 is not limited to one surface of the reaction chamber wall 14, and is appropriately selected so that the reaction by-product does not adhere to the reaction chamber wall 14. The blowing of the inert gas 56 may be performed not only from the side wall surface side of the reaction chamber but also from the upper and lower sides of the reaction chamber wall 14 surface.

The inert gas 56 is introduced from the inert gas second introduction nozzle 62 into the bag structure portion of the bellows 46 provided to move the susceptor 18 up and down while the reaction chamber 12 is kept airtight. Prevent reaction by-products from entering and accumulating inside the structure.
The inert gas 56 may be introduced into the reaction chamber 12 in a state where the inert gas 56 is heated to a temperature at which the reaction by-products are aggregated and do not adhere to the reaction chamber wall 14.

Next, the operation of the substrate processing apparatus 50 will be described.
After exhausting the inside of the reaction chamber 12 by the exhaust pipe 40 by an exhaust pump (not shown), the gate valve 44 is opened, and the substrate 38 is transferred onto the susceptor 18 by the cooperation of the wafer pins 48 and the transfer robot (not shown). The reaction gases 22 and 24 having a constant flow rate are introduced from the reaction gas introduction unit 20, and at the same time, the inert gas 56 is introduced into the reaction chamber 12 from the inert gas first introduction nozzle 58 and the inert gas second introduction nozzle 62. The pressure in the reaction chamber 12 is maintained at a predetermined value by an exhaust conductance control valve (not shown).

  When high frequency power output from the oscillator 30 is supplied to the upper electrode 16 and the susceptor shaft 52 via the matching unit 32, plasma 34 is generated in the reaction chamber 12, and the substrate to be processed 38 placed on the susceptor 18 is processed. Is done.

  At this time, reaction by-products generated in the region of the plasma 34 generated between the susceptor 18 and the gas shower plate 26 adhere to each part of the members in the reaction chamber 12. These gases are exhausted while being prevented by the inert gas 56 flowing in a laminar flow parallel to 38. The inert gas 56 is configured to flow between the lower portion of the susceptor 18 and the reaction chamber wall 14. Further, the overall shape of the reaction chamber 12 is not limited to the above configuration, and the inner wall of the reaction chamber 12 may have a round shape with no corners (see FIG. 5).

When forming the film, if the inert gas 56 is introduced from a direction different from the reaction gas, the inert gas 56 may hinder the film formation. Specifically, the concentration of the inert gas 56 is lower as it is directly above the substrate to be processed 38 upstream of the inert gas 56, and the inert gas is stored in proportion to the distance from the inert gas introduction portion as it is downstream. Therefore, the inert gas concentration becomes high. As a countermeasure, a shielding plate or the like for shielding the inert gas 56 may be provided on the gas shower plate 26 so that the inert gas 56 does not easily flow over the substrate to be processed 38.
Further, the inert gas 56 may be made difficult to flow on the substrate to be processed 38 by narrowing the distance between the upper electrode 16 and the susceptor 18. Further, a windshield plate may be provided around the susceptor 18 in order to adjust the flow of the inert gas 56.

The gas type of the inert gas 56 supplied in parallel to the substrate from the inert gas first introduction nozzle 58 is generally N ₂ , Ar, He, or the like. The inert gas 56 supplied in parallel does not adversely affect the film formation, and it is preferable to use the same gas as the inert carrier gas supplied together with the reaction gas.
The introduction timing of the inert gas 56 supplied in parallel is preferably just before or simultaneously with the supply of the reaction gases 22, 24, because the reaction gas can be saved and the condition is that before the RF discharge. .
In addition, the inert gas 56 supplied in parallel is preferably introduced at a flow rate of about 20 times the total flow rate of the reaction gases 22 and 24.

The processing conditions are, for example, a total flow rate of reaction gas (SiH ₄ , NH ₃ , N _2, etc.) of 0.5 slm, a flow rate of inert gas (N ₂ ) of 1 to 100 slm, a susceptor temperature of 350 ° C., and a reaction chamber The pressure is set to 10 to 931 Pa, and the substrate 38 is processed.
At this time, if the pressure is too high, stagnation occurs in the gas. The lower the pressure, the easier the gas will be in a laminar flow state and the less likely it is to stagnate. Particularly, 10 to 931 Pa is preferable because a good film is formed.
In addition, an inert gas concentration of 10 to 100 slm is preferable because the reaction gas and the inert gas are well separated to form a good film with less by-product adhesion.
For example, when a 300 mm wafer is used as the substrate to be processed 38, the length in the longitudinal direction of the reaction chamber 12 is preferably 500 mm or less.

  FIG. 4 shows another embodiment. The shape of the upper electrode 16 of the substrate processing apparatus 50 described above is changed. The entire upper electrode 16 is shaped like a mushroom upside down, and a structure corresponding to the stem is introduced with the introduction of the reaction gases 22 and 24 and the high frequency power output from the oscillator 30 through the matching unit 32. It has become.

  In addition, the inert gas 56 introduced into the reaction chamber 12 flows between the upper portion of the upper electrode 16 and the reaction chamber wall 14, and the inert gas 56 that has passed through the upper portion of the upper electrode 16. Flows from above the reaction chamber 12 to the exhaust port 60.

  In another embodiment shown in FIG. 5, the inert gas first introduction nozzle 58 is provided such that the blowout is directed in the opposite direction with respect to the susceptor 18 (substrate to be processed 38), and the inert gas 56 is made to flow. The reaction chamber 12 is configured to collide with the inner wall. By colliding with the inner wall of the reaction chamber 12, the pressure of the inert gas 56 flowing to the substrate to be processed 38 is reduced, and the substrate 38 to be processed can be prevented from being exposed to the excessive inert gas 56.

  The present invention is particularly effective for an apparatus using parallel plates, and a direction different from that of an inert gas is provided so that by-products do not adhere to the processing chamber when a substrate is processed between a pair of plate electrodes. From which an inert gas is supplied.

It is side surface sectional drawing which shows the conventional substrate processing apparatus. It is side surface sectional drawing which shows the substrate processing apparatus with which one Embodiment of this invention is applied. It is side surface sectional drawing which shows the substrate processing apparatus with which one Embodiment of this invention is applied. It is side surface sectional drawing which shows the substrate processing apparatus with which other embodiment of this invention is applied. It is side surface sectional drawing which shows the substrate processing apparatus with which other embodiment of this invention is applied.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 Parallel plate type substrate processing apparatus 12 Reaction chamber 14 Reaction chamber wall 16 Upper electrode 18 Susceptor 30 Oscillator 32 Matching device 34 Plasma 38 Substrate 48 Wafer pin 50 Substrate processing device 52 Susceptor shaft 54 Rotation introduction terminal 56 Inert gas 58 Inert Gas first introduction nozzle 60 Exhaust port 62 Inert gas second introduction nozzle

Claims (5)

A processing chamber for processing the substrate;
A substrate support for supporting the substrate in the processing chamber;
A reaction gas supply system provided to face the substrate support surface of the substrate support portion, and for supplying a reaction gas into the processing chamber;
An inert gas supply system in which a plurality of inert gas supply nozzles are provided in the vicinity of the processing chamber wall so that the inert gas is supplied from a direction different from the reaction gas;
A gas exhaust system for exhausting the gas in the processing chamber;
A substrate processing apparatus. The opening of the inert gas supply nozzle is directed in the direction opposite to the wafer, and the inert gas is supplied in the direction of the substrate after colliding with the inner wall of the processing chamber.
The substrate processing apparatus according to claim 1. The inert gas supply nozzle is provided so that an inert gas is supplied in parallel to the substrate.
The substrate processing apparatus according to claim 1. Providing a shielding plate between the substrate support and the reactive gas supply system;
The substrate processing apparatus according to claim 1. Having a plasma generator for supplying the reaction gas between a pair of opposed flat plate electrodes and applying high frequency power to at least one flat plate electrode of the pair of flat plate electrodes to generate plasma in the processing chamber;
The substrate processing apparatus according to claim 1.

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