JP2002231711A - Cleaning equipment of deposition chamber using remote plasma - Google Patents

Abstract

PROBLEM TO BE SOLVED: To decrease plasma ignition electric power and improve durability of a constituent like an electrode while the whole body is made compact and cost is reduced, and enable proper cleaning inside a deposition chamber by effectively generating plasma. SOLUTION: In this cleaning equipment, reactive excitation species are introduced in the deposition chamber 2 from a remote high frequency discharge tube 1 in which plasma is generated by applying high frequency power, precursor gas is activated and the reactive excitation species can be generated. The remote high frequency discharge tube 1 is constituted of an insulating tubular vessel 5 and an inductive coupling type electrode 7 for high frequency discharge which is wound around the vessel 5 in a spiral coil form. The electrode 7 is constituted of a large diameter conductive metal tube 8 which is wound in a coil form in the state that cooling water can be made to flow inside, and a small diameter high frequency power line 9 which is arranged between spiral pitches of the metal tube 8 and wound in a coil form.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to an apparatus for cleaning a deposition chamber by remote plasma. More specifically, a remote plasma used for cleaning the inside of a deposition chamber of a film forming apparatus used in a manufacturing process of various semiconductors and flat displays, such as a chemical vapor deposition (eg, plasma CVD) or a sputtering apparatus. And an apparatus for cleaning a deposition chamber.

[0002]

2. Description of the Related Art In plasma CVD, for example, a substrate is placed in a vacuum deposition chamber provided with a pair of thin plate parallel electrodes, a reaction gas is flowed into the deposition chamber through an upper electrode, and a high frequency (RF) voltage is applied to the pair of parallel electrodes. A predetermined product is manufactured by decomposing the reaction gas and depositing a material such as silicon nitride (SiN) on the surface of the substrate by generating plasma in the reaction gas by applying to the electrode. .

In a film forming apparatus used in a manufacturing process of such a semiconductor or a flat display, although a material such as silicon nitride (SiN) is designed to be preferentially deposited on a surface of a substrate, it is designed. Part of the material is also deposited on other parts in the deposition chamber, for example, on the inner wall surface of the chamber or on components exposed in the chamber. Therefore, after repeated use, it is necessary to perform cleaning to remove the material deposition layer increasing in the chamber.

Conventionally, an in-situ cleaning method (commonly called an in-situ cleaning method) has been used as a means for cleaning this type of deposition chamber.
In this in-situ cleaning method, a precursor gas is directly introduced into a deposition chamber, and a glow discharge plasma is generated in the deposition chamber. In this method, excited species are generated, and the reactive excited species forms a volatile compound with a material deposit in the chamber, thereby cleaning a surface inside the chamber.

However, in the case of the in-situ cleaning method as described above, plasma is generated and used in a deposition chamber to generate reactive excited species. In order to obtain a high cleaning rate, a high power is required, and the higher the power level, the more easily the hardware inside the chamber is damaged, and the shorter the service life of the deposition chamber. As a result, the cost per substrate of a product manufactured by the system using the deposition chamber is increased. In addition, high-power in-situ cleaning methods can damage other system components and components,
Alternatively, there is a problem that a residue or a by-product which cannot be removed except by physically wiping the inside of the chamber is easily generated.

As cleaning means for solving the problems of the conventional general in-situ cleaning method,
For example, Japanese Patent Application Laid-Open Nos. 10-14989 and 9-6
As disclosed in No. 9504 and the like, a plasma is generated in a chamber located at a remote position apart from the deposition chamber to generate reactive excited species, and the reactive excited species is introduced into the deposition chamber. Means for cleaning the deposition chamber by remote plasma for cleaning the inside of the deposition chamber by using the method has been proposed.

[0007]

However, in the conventionally proposed means for cleaning a deposition chamber by remote plasma, in order to efficiently generate plasma in the remote chamber, the frequency of the high-frequency power applied to the electrode must be reduced. The higher the frequency of the power applied to the electrode, the more the skin effect becomes significant and the high-frequency resistance increases, which not only increases the power loss but also the electrode itself. As a result, the electrodes and the remote chamber, the pipe connecting the remote chamber and the deposition chamber, and the like are easily burned, thereby adversely affecting their durability.

In addition, after plasma ignition, it is necessary to stabilize the plasma by suppressing an increase in reflected power generated by application of high-frequency power and an adverse effect due to thermal plasma in order to maintain a predetermined cleaning performance. For this purpose, it is required to provide an automatic power adjusting device or the like for reducing the power applied to the electrodes compared to the time of ignition, and as a result, there has been a problem that the entire device becomes large and expensive.

[0009] The present invention has been made in view of the above circumstances, and while the whole is compact and low cost,
In addition to reducing the plasma ignition power and improving the durability of components such as electrodes, it is possible to generate plasma stably and efficiently to properly clean the inside of the deposition chamber without generating residues and by-products. It is an object of the present invention to provide a device for cleaning a deposition chamber by means of a remote plasma.

[0010]

To achieve the above object, a remote plasma cleaning apparatus for a deposition chamber according to the present invention is provided with an inductively coupled high-frequency discharge electrode on the outer periphery of an insulating tubular container in a spiral coil shape. The precursor gas is supplied into the tubular container of the remote high-frequency discharge tube configured by being wound around, and high-frequency power is applied to the coiled high-frequency discharge electrode to generate plasma in the tubular container. A cleaning apparatus for a deposition chamber by remote plasma for activating a precursor gas to generate a reactive excited species and introducing the reactive excited species into a deposition chamber to clean the inside of the chamber, wherein the high-frequency discharge electrode Is a large-diameter conductive metal wound in a spiral coil shape around the outer periphery of an insulating tubular container so that cooling water can flow through it. And a small-diameter high-frequency power line arranged between the spiral pitches of the large-diameter conductive metal tube and wound around the outer periphery of the insulating tubular container in a spiral coil shape. The end on the outlet side and the end on the exhaust gas inlet side of the small-diameter high-frequency power line are electrically connected.

According to the present invention having the above-described characteristic configuration, the frequency of the power applied to the electrode can be increased by flowing the cooling water inside the large-diameter conductive metal tube constituting the high-frequency discharge electrode. Even if it is set, the heat loss due to the skin effect can be suppressed to reduce power loss,
The remote high-frequency discharge tube serving as the remote chamber and the tube connecting the remote high-frequency discharge tube and the deposition chamber are not burned, and their durability can be improved. Furthermore, by placing the small-diameter high-frequency power line in the dead space between the helical pitches of the large-diameter conductive metal tubes, the cooling effect on the small-diameter high-frequency power line is maintained, and the overall length of the high-frequency discharge tube is shortened for compactness. However, it is possible to increase the number of turns of the entire high-frequency discharge electrode, reduce the plasma ignition power, and efficiently generate inductively coupled plasma.

Further, after plasma ignition, an increase in reflected power and an adverse effect due to thermal plasma are suppressed by the cooling action of the two coil-shaped electrodes, so that it is not necessary to provide a special automatic power adjusting device or the like, and the cost of the entire device is reduced. While reducing
It is possible to generate plasma stably and activate the precursor gas almost completely, and to prevent the precursor gas from being introduced into the deposition chamber without being decomposed,
As a result, highly reactive excited species can be introduced into the deposition chamber to perform reliable and proper cleaning without generating residues and by-products, and discharge of precursor gases that have an adverse effect on the environment. The amount can be greatly reduced.

In the apparatus for cleaning a deposition chamber by remote plasma having the above-described structure, one or a plurality of small-diameter high-frequency power lines are arranged as the high-frequency discharge electrodes for each of a plurality of spiral pitches of a large-diameter conductive metal tube. It may be wound in a spiral coil shape. However, in consideration of plasma ignition performance, improvement of durability by cooling action, and maintenance of precursor gas activation performance, a plurality of large-diameter conductive metal tubes are required. It is most desirable that at least one of the small-diameter high-frequency power lines is arranged in the entire spiral pitch and wound in a spiral coil shape.

The precursor gas supplied into the tubular vessel of the remote high-frequency discharge tube in the apparatus for cleaning a deposition chamber by the remote plasma having the above-mentioned structure is C
Fluorinated gases such as perfluorinated carbon gas such as F ₄ , C ₂ F ₆ , C ₃ F ₈ , C ₆ F ₁₄ , fluorinated nitrogen gas such as NF ₃ , and fluorinated sulfur gas such as SF _{6 and the} like; the may be used one selected from among a mixed gas. in particular, NF ₃
By using a fluorinated nitrogen gas such as silicon (Si), doped silicon, silicon nitride (Si
_The chamber on which 3N ₄ ) and silicon oxide (SiO ₂ ) are deposited can be cleaned, and can be effectively used in a system having a plurality of process chambers used for manufacturing an active matrix liquid crystal display (AMLCD).

Further, in the apparatus for cleaning a deposition chamber by remote plasma having the above structure, a filter is provided for removing unnecessary materials from the reactive excited species before the reactive excited species is introduced into the deposition chamber. By removing particulate matter that may be generated during activation of the precursor gas and undesired materials that may be produced in the remote RF discharge tube as a by-product of the reaction, Cleaning performance can be further improved. The filter may be made of a ceramic material having a micron-unit pore size, or may be made of another material such as Teflon (registered trademark).

[0016]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a schematic configuration diagram of an entire apparatus for cleaning a deposition chamber by remote plasma according to the present invention, and shows a precursor gas G, for example, CF ₄ , C ₂ F.
_{6, C 3 F 8, C} 6 F 14 or the like of the PCF (perfluorinated carbons)
Gas, fluorinated nitrogen gas such as NF _3, precursor gases G selected from among fluorine-based gas and a mixed gas thereof, such as fluorinated sulfur gases such as SF ₆ is capable of supplying a plasma the precursor gas A high-frequency discharge tube 1 that can be activated as it is generated to generate reactive excited species is placed at an appropriate distance from a deposition chamber 2 of a film forming apparatus used in a manufacturing process of various semiconductors and flat displays. The remote high-frequency discharge tube 1 and the deposition chamber 2 are connected via a pipe 3 at a remote position, and the reactive gas before being introduced into the deposition chamber 2 is located in the middle of the pipe 3. A filter 4 for removing unnecessary materials from the excited species is provided.

As shown in FIG. 2, the high-frequency discharge tube 1 has a supply port 5a for the precursor gas G and a discharge port 5b for the reactive excitation species connected to the pipe 3, for example, a heat-resistant ceramic. Alternatively, an insulating tubular container 5 of quartz glass or the like
And an inductively coupled high-frequency discharge, which is wound in a spiral coil shape around the outer periphery of the tubular container 5 and can generate plasma in the tubular container 5 by applying a high-frequency power of 2 MHz from a high-frequency power source 6. And an electrode 7. The pressure condition in the plasma processing in the high-frequency discharge tube 4 is 133 to 665 Pa (1 to 5 torr).
Set to about.

As shown in FIG. 3, the high-frequency discharge electrode 7 is spirally wound around the outer periphery of the insulating tubular container 5 so that the cooling water CW can flow therethrough. And the like, and a large-diameter conductive metal tube 8.
And a small-diameter high-frequency power line 9 such as a litz wire wound around the outer periphery of the insulating tubular container 5 in a spiral coil shape. The end 8 of the large-diameter conductive metal tube 8 that constitutes the high-frequency discharge electrode 7 on the discharge port 5b side.
b and the end 9a on the supply port 5a side of the small-diameter high-frequency power line 9 are electrically connected via a lead wire 10, and the end 8a of the large-diameter conductive metal tube 8 on the supply port 5a side and the small diameter. The end 9b of the high-frequency power line 9 on the side of the outlet 5b is connected to the high-frequency power source 6, and thereby the high-frequency discharge electrode 7
The total number of coil turns is twice as large as the number of coil turns of the large-diameter conductive metal tube 8.

According to the apparatus for cleaning a deposition chamber by remote plasma configured as described above, the precursor gas G is supplied into the insulating tubular container 5 of the remote high-frequency discharge tube 1 and the high-frequency power supply 6 High frequency power of about 2 MHz is applied to the
By generating plasma by inductive coupling inside, the precursor gas G is activated, and highly reactive excited species such as ions and radicals are generated in the tubular container 5. This reactive excited species passes through the pipe 3 to the deposition chamber 2
Before the introduction, the reactive excited species is passed through the filter 4 to remove unnecessary materials such as particulate matter and reaction by-products contained in the excited species. You.

The reactive excited species after unnecessary materials have been removed by the filter 4 are introduced into the deposition chamber 2, and the components exposed on the inner wall surface of the chamber 2 and inside the chamber 2 by the etching action. Thus, a predetermined cleaning is performed by removing the material deposition layer adhering to the substrate.

When cleaning the inside of the deposition chamber 2 by such inductively coupled remote plasma, the cooling water CW is allowed to flow through the inside of the large-diameter conductive metal tube 8 constituting the high-frequency discharge electrode 7 so that the electrode 7 is Even if the frequency of the applied power is set as high as about 2 MHz,
In addition to suppressing heat generation due to the skin effect to reduce power loss, the electrode 7, the remote high-frequency discharge tube 1 serving as a remote chamber, and the remote high-frequency discharge tube 1 and the deposition chamber 2
Thus, the durability of the pipes 3 and the like connecting them can be prevented by preventing burnout. Further, by arranging the small-diameter high-frequency power line 9 in a dead space between the helical pitches of the large-diameter conductive metal tube 8, the cooling effect on the small-diameter high-frequency power line 9 is also kept good, and the total length L of the remote high-frequency discharge tube 1 is reduced. While shortening the length of the apparatus to make the whole apparatus compact, the number of coil turns of the entire high-frequency discharge electrode 1 is increased, the plasma ignition power is reduced, and inductively coupled plasma can be efficiently generated.

Further, after plasma ignition, an increase in reflected power and an adverse effect due to overheated plasma are suppressed by the cooling action of the coiled electrodes 8, 9, so that a special automatic power adjusting device or the like is not provided and the cost of the entire device is reduced. It is possible to generate plasma stably and almost completely activate the precursor gas G while preventing the precursor gas G from being introduced into the deposition chamber 2 without being decomposed, As a result, a highly reactive excited species can be reliably introduced into the deposition chamber 2 to perform reliable and proper cleaning without generation of residues and by-products. And adverse effects on the environment can be greatly reduced.

In the above-described embodiment, the small-diameter high-frequency power lines 9 are arranged one by one at all intervals between the plurality of spiral pitches of the large-diameter conductive metal tube 8 and are wound in a spiral coil shape. By using the electrode 7, the cooling effect accompanying the circulation of the cooling water CW can exert an excellent effect on improving the durability and plasma ignition performance of the entire high-frequency discharge electrode 7 and maintaining the activation performance of the precursor gas. However, as shown in FIG. 4, for example, as shown in FIG. 4, a plurality of large-diameter conductive metal tubes 8 are shown (two in the drawing, but may be three or more).
One or more small-diameter high-frequency power lines 9 are arranged for each helical pitch, and a high-frequency discharge electrode 7 formed by winding a spiral coil, and a plurality of large-diameter conductive metal tubes 8 as shown in FIG. The high-frequency discharge electrode 7 or the like formed by arranging two small-diameter high-frequency power lines 9 every two turns and spirally winding them in a spiral coil shape may be used.

[0024]

As described above, according to the present invention, the frequency of the applied power is set high by the cooling action of flowing the cooling water inside the large-diameter conductive metal tube constituting the high-frequency discharge electrode. In addition, it is possible to reduce power loss by suppressing heat generation due to the skin effect, and to eliminate burnout of electrodes, a remote high-frequency discharge tube serving as a remote chamber, and a tube connecting the remote high-frequency discharge tube and the deposition chamber. Can be improved in durability. Furthermore, by placing the small-diameter high-frequency power line in the dead space between the helical pitches of the large-diameter conductive metal tubes, the cooling effect on the small-diameter high-frequency power line is maintained, and the overall length of the high-frequency discharge tube is shortened for compactness. However, it is possible to increase the number of turns of the entire high-frequency discharge electrode, reduce the plasma ignition power, and efficiently generate inductively coupled plasma.

In addition, it is possible to suppress the increase in the reflected power and the adverse effect of the overheated plasma by the cooling action of the two coil-shaped electrodes, and to reduce the cost of the entire apparatus without providing a special automatic power adjusting apparatus or the like. The plasma is generated stably and the precursor gas is almost completely activated, so that the precursor gas is not introduced into the deposition chamber without being decomposed. High-excitation species can be reliably introduced to perform proper cleaning without generating residues and by-products, and the amount of precursor gas emitted can be reduced to suppress adverse effects on the environment. It has the effect of being able to.

In particular, using a high-frequency discharge electrode having a configuration in which at least one small-diameter high-frequency power line is arranged and wound in a spiral coil shape between all of the plurality of spiral pitches of the large-diameter conductive metal tube. Thereby, the cooling effect accompanying the flow of the cooling water can exert excellent effects on the durability of the entire high-frequency discharge electrode, the improvement of the plasma ignition performance, and the maintenance of the activation performance of the precursor gas.

[Brief description of the drawings]

FIG. 1 is a schematic configuration view of an entire apparatus for cleaning a deposition chamber by remote plasma according to the present invention.

FIG. 2 is a front view showing a configuration of a high-frequency discharge tube in the same device.

FIG. 3 is an enlarged front view of a main part of FIG. 2;

FIG. 4 is an enlarged vertical sectional front view of a main part showing another embodiment of the high-frequency discharge tube in the above device.

FIG. 5 is an enlarged vertical sectional front view of a main part showing another embodiment of the high-frequency discharge tube in the above device.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Remote high frequency discharge tube 2 Deposition chamber 3 Piping 4 Filter 5 Insulating tubular container 7 High frequency discharge electrode 8 Large diameter conductive metal tube 9 Small diameter high frequency power line G Precursor gas

Continued on the front page (72) Inventor Yoshihiro Masui 3-8-13 Minamikagaya, Suminoe-ku, Osaka-shi Pearl Industry Co., Ltd. (72) Inventor Noboru Saeki 3-8-13 Minamikagaya, Suminoe-ku, Osaka-shi, Osaka No. Pearl Industry Co., Ltd. F term (reference) 4K030 DA06 KA08 KA30 5F004 AA15 BA03 BA20 DA00 DA01 DA02 DA03 DA18 5F045 AA08 AE21 BB08 BB14 EB06 EE10 EH12 EH18 EJ05 EJ09

Claims (4)

[Claims] 1. A precursor gas is supplied into a tubular container of a remote high-frequency discharge tube formed by winding an inductively coupled electrode for high-frequency discharge around an outer periphery of an insulative tubular container in a helical coil shape. The precursor gas is activated by applying high-frequency power to the electrode for high-frequency discharge to generate plasma in the tubular container, thereby generating reactive excited species, and introducing the reactive excited species into the deposition chamber. A high-frequency discharge electrode is wound in a spiral coil shape around the outer periphery of the insulating tubular container in a state in which cooling water can flow therein. A large-diameter conductive metal tube, and a small-diameter high-perimeter disposed between the helical pitches of the large-diameter conductive metal tube and spirally wound around the outer periphery of the insulating tubular container. A power line, and an end of the large-diameter conductive metal tube on the exhaust gas outlet side and an end of the small-diameter high-frequency power line on the exhaust gas inlet side are electrically connected to each other by remote plasma. Cleaning equipment for the deposition chamber. 2. The high-frequency discharge electrode according to claim 1, wherein at least one small-diameter high-frequency power line is disposed between all of the plurality of helical pitches of the large-diameter conductive metal tube and wound into a spiral coil. Item 2. A cleaning apparatus for a deposition chamber by remote plasma according to item 1. 3. The precursor gas supplied into the tubular vessel of the remote high-frequency discharge tube is CF ₄ , C ₂ F ₆ , C ₃ F ₈ ,
C ₆ F ₁₄ perfluorinated carbon gas such claim is a member selected from among fluorine-based gas and a mixed gas thereof, such as fluorinated nitrogen gas, fluorinated sulfur gases such as SF _6, such as NF ₃ 3. The apparatus for cleaning a deposition chamber by remote plasma according to 1 or 2. 4. A filter for removing unnecessary materials from the reactive excited species before the reactive excited species is introduced into the deposition chamber.
The apparatus for cleaning a deposition chamber by remote plasma according to any one of the above.