KR102344256B1 - Apparatus for treating substrate - Google Patents

Abstract

A substrate processing apparatus is provided. A substrate processing apparatus includes a process chamber providing a processing space for a substrate, a substrate support for supporting the substrate, a showerhead spraying a process gas to the substrate, and an isolation unit surrounding an edge of the showerhead, A side exposure space for exposing a side surface of the showerhead to the processing space is formed between the showerhead and the isolation unit.

Description

Substrate processing apparatus

The present invention relates to a substrate processing apparatus for controlling the density of plasma by controlling the concentration of a fluorine component included in a process chamber.

When manufacturing a semiconductor device or a display device, various processes such as photography, etching, ashing, ion implantation, thin film deposition, and cleaning are performed. Here, the photographic process includes coating, exposure, and developing processes. A photoresist is applied on a substrate (ie, a coating process), a circuit pattern is exposed on the substrate on which a photosensitive film is formed (ie, an exposure process), and an exposed area of the substrate is selectively developed (ie, a developing process).

In general, plasma may be used to etch a thin film formed on a wafer or a substrate in a semiconductor manufacturing process. The thin film may be etched by causing plasma to collide with the wafer or substrate by an electric field formed inside the process chamber.

An object of the present invention is to provide a substrate processing apparatus for controlling the density of plasma by controlling the concentration of a fluorine component included in a process chamber.

The problems of the present invention are not limited to the problems mentioned above, and other problems not mentioned will be clearly understood by those skilled in the art from the following description.

One aspect of the substrate processing apparatus of the present invention for achieving the above object includes a process chamber providing a process space for a substrate, a substrate support for supporting the substrate, and injecting a process gas to the substrate. A showerhead and an isolation unit surrounding an edge of the showerhead, wherein a side exposure space is formed between the showerhead and the isolation unit to expose a side surface of the showerhead to the processing space.

The substrate processing apparatus may further include a plasma generator configured to excite the process gas into a plasma state, and plasma particles generated by exciting the target gas included in the process gas into a plasma state react with the showerhead in the side exposure space Thus, the density in the processing space is reduced.

The target gas includes a gas containing fluorine.

An inner surface of the isolation unit facing the side surface of the showerhead includes an inclined surface inclined toward the processing space.

The side exposure space is connected to an auxiliary gas conveying pipe for transporting the auxiliary gas, and the auxiliary gas transferred through the auxiliary gas conveying pipe is injected into the process processing space through the side exposure space.

The auxiliary gas includes helium gas.

The substrate processing apparatus further includes a control unit controlling the injection of the auxiliary gas.

The substrate processing apparatus may further include a focus ring disposed to surround an edge of the substrate support part to control an electric field formed at the edge of the substrate support part, and the controller may include an injection amount of the auxiliary gas according to an etching state of the focus ring. adjust the

The control unit increases the injection amount of the auxiliary gas at the end of use compared to the initial use of the focus ring.

The details of other embodiments are included in the detailed description and drawings.

1 is a view showing a substrate processing apparatus according to an embodiment of the present invention.
FIG. 2 is an enlarged view of A shown in FIG. 1 .
3 and 4 are diagrams for explaining the function of the side exposure space shown in FIG. 2 .
5 and 6 are diagrams for explaining the control of the plasma incident angle according to the state of the focus ring shown in FIG. 1 .

Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings. Advantages and features of the present invention, and a method for achieving them will become apparent with reference to the embodiments described below in detail in conjunction with the accompanying drawings. However, the present invention is not limited to the embodiments published below, but may be implemented in various different forms, and only these embodiments allow the publication of the present invention to be complete, and common knowledge in the technical field to which the present invention pertains It is provided to fully inform the possessor of the scope of the invention, and the present invention is only defined by the scope of the claims. Like reference numerals refer to like elements throughout.

Reference to an element or layer “on” or “on” another element or layer includes not only directly on the other element or layer, but also with other layers or other elements intervening. include all On the other hand, reference to an element "directly on" or "directly on" indicates that no intervening element or layer is interposed.

Spatially relative terms "below", "beneath", "lower", "above", "upper", etc. It can be used to easily describe the correlation between an element or components and other elements or components. The spatially relative terms should be understood as terms including different orientations of the device during use or operation in addition to the orientation shown in the drawings. For example, when an element shown in the figures is turned over, an element described as "beneath" or "beneath" another element may be placed "above" the other element. Accordingly, the exemplary term “below” may include both directions below and above. The device may also be oriented in other orientations, and thus spatially relative terms may be interpreted according to orientation.

It should be understood that although first, second, etc. are used to describe various elements, components, and/or sections, these elements, components, and/or sections are not limited by these terms. These terms are only used to distinguish one element, component, or sections from another. Accordingly, it goes without saying that the first element, the first element, or the first section mentioned below may be the second element, the second element, or the second section within the spirit of the present invention.

The terminology used herein is for the purpose of describing the embodiments and is not intended to limit the present invention. In this specification, the singular also includes the plural unless specifically stated otherwise in the phrase. As used herein, "comprises" and/or "comprising" refers to the presence of one or more other components, steps, operations and/or elements mentioned. or addition is not excluded.

Unless otherwise defined, all terms (including technical and scientific terms) used herein may be used with the meaning commonly understood by those of ordinary skill in the art to which the present invention belongs. In addition, terms defined in a commonly used dictionary are not to be interpreted ideally or excessively unless clearly defined in particular.

Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings, and in the description with reference to the accompanying drawings, the same or corresponding components are given the same reference numbers regardless of reference numerals, A description will be omitted.

1 is a view showing a substrate processing apparatus according to an embodiment of the present invention.

Referring to FIG. 1 , the substrate processing apparatus 10 includes a process chamber 100 , a substrate support unit 200 , a process gas tank 310 , an auxiliary gas tank 320 , a showerhead 400 , and a plasma generator 500 . ) and a control unit 600 .

The process chamber 100 provides a process processing space 101 of the substrate W. The process chamber 100 is made of a metal material and may be grounded. An outlet 120 may be provided on the bottom surface of the process chamber 100 . The outlet 120 is connected to the outlet line 121 . By-products and gases generated during the process of the substrate W may be discharged to the outside through the discharge port 120 and the discharge line 121 .

A liner 130 may be provided inside the process chamber 100 . The liner 130 may prevent the inner surface of the process chamber 100 from being damaged by arc discharge. Also, the liner 130 may prevent impurities generated while a process for the substrate W is performed from being deposited in the process chamber 100 . To this end, the liner 130 may be attached to the inner surface of the process chamber 100 so as to surround the substrate support 200 .

The substrate support unit 200 serves to support the substrate (W). The substrate support 200 may be disposed under the process processing space 101 . The substrate support 200 includes a base plate 210 , a main body 220 , a chuck 230 , a focus ring 240 , and a ring supporter 250 .

The base plate 210 serves to support the main body 220 , the chuck 230 , the focus ring 240 , and the ring supporter 250 . The base plate 210 may be an insulator.

The main body 220 may be provided between the base plate 210 and the chuck 230 . A heat medium circulation pipe 221 and a refrigerant circulation pipe 222 may be provided inside the main body 220 . The thermal medium may circulate through the thermal medium circulation pipe 221 , and the refrigerant may circulate through the refrigerant circulation pipe 222 . The heat medium circulation pipe 221 and the refrigerant circulation pipe 222 may be arranged in a spiral shape inside the main body 220 . As the thermal medium circulates through the thermal medium circulation pipe 221 , the main body 220 is heated, and as the refrigerant circulates through the refrigerant circulation pipe 222 , the main body 220 may be cooled.

The main body 220 may be made of metal. The chuck 230 in close contact with the main body 220 may be affected by the temperature of the main body 220 . As the main body 220 is heated, the chuck 230 may be heated, and as the main body 220 cools, the chuck 230 may be cooled.

A thermal medium supply pipe 221a for supplying a thermal medium to the upper portion of the chuck 230 may be connected to the thermal medium circulation pipe 221 . A thermal medium may be supplied to the substrate W through the thermal medium supply pipe 221a.

The chuck 230 serves to support the substrate (W). In the present invention, the chuck 230 may be an electrostatic chuck. That is, the chuck 230 may adsorb the substrate W by electrostatic force. However, the chuck 230 of the present invention is not limited to the electrostatic chuck, and the chuck 230 may hold and support the substrate W in a mechanical manner. Hereinafter, the chuck 230 will be mainly described as an electrostatic chuck.

The body of the chuck 230 may be a dielectric material. An electrostatic electrode 231 and a heating unit 232 may be provided inside the chuck 230 . The electrostatic electrode 231 may be electrically connected to the first power supply unit 231a. The electrostatic electrode 231 may generate an electrostatic force by the power supplied from the first power supply unit 231a. The substrate W may be adsorbed to the chuck 230 by the corresponding electrostatic force.

The heating unit 232 may be electrically connected to the second power supply 232a. The heating unit 232 may be heated by power supplied from the second power supply 232a. Heat of the heating unit 232 may be transferred to the substrate (W). The substrate W may be maintained at a constant temperature by the heat of the heating unit 232 . The heating unit 232 may be provided in the form of a coil and may be arranged in a spiral shape inside the chuck 230 .

The focus ring 240 may be provided in the form of a ring to surround the edge of the chuck 230 . The focus ring 240 serves to adjust an electric field formed at the edge of the chuck 230 . To this end, the focus ring 240 may be formed of a material having a dielectric constant of a certain size.

The ring supporter 250 may support the focus ring 240 with respect to the base plate 210 . The focus ring 240 may maintain a predetermined height with respect to the base plate 210 by the ring support 250 to maintain a state surrounding the edge of the chuck 230 . The ring support 250 may be formed of an insulating material.

The process gas tank 310 may store the process gas GS1 . The process gas GS1 may be transferred through the first inlet line 111 to be injected into the process chamber 100 . A process gas valve V1 may be provided in the first inlet line 111 connecting the process gas tank 310 and the process gas inlet 110 . When a process treatment is performed on the substrate W, the first inlet line 111 is opened by the process gas valve V1 to inject the process gas GS1 into the process space 101 of the process chamber 100 . can be In addition, when the process treatment of the substrate W is completed, the first inlet line 111 is closed by the process gas valve V1 to prevent the process gas GS1 from being injected into the process chamber 100 . can

The auxiliary gas tank 320 may store the auxiliary gas GS2 . The auxiliary gas GS2 serves to prevent contact between the target gas and the showerhead 400, which will be described later. The auxiliary gas GS2 may be transferred through the second inlet line 112 to be injected into the process chamber 100 . An auxiliary gas valve V2 may be provided in the second inlet line 112 connecting the auxiliary gas tank 320 and the process chamber 100 . When it is desired to prevent contact between the target gas and the showerhead 400 , the second inlet line 112 is opened by the auxiliary gas valve V2 to allow the auxiliary gas GS2 to enter the process processing space 101 of the process chamber 100 . ) can be injected. In addition, when it is desired to allow contact between the target gas and the showerhead 400 , the second inlet line 112 is closed by the auxiliary gas valve V2 to inject the auxiliary gas GS2 into the process chamber 100 . can be blocked.

The showerhead 400 serves to inject a process gas GS1 for a process on the substrate W to the substrate W. The showerhead 400 may be disposed above the processing space 101 . The showerhead 400 may have an accommodation space for temporarily accommodating the process gas GS1 . The process gas GS1 introduced through the process gas inlet 110 may be injected after being accommodated in the accommodation space.

The showerhead 400 may include an injection hole SH through which the process gas GS1 is injected. The process gas GS1 may be introduced into the process processing space 101 through the injection hole SH. The process gas GS1 sprayed from the showerhead 400 is sprayed downward to reach the substrate W.

An isolation unit 410 may be provided adjacent to the showerhead 400 . The isolation part 410 may surround the edge of the showerhead 400 . Exposure of the side surface of the showerhead 400 to the processing space 101 may be restricted by the isolation unit 410 . The isolation unit 410 may partially prevent the gas or plasma included in the processing space 101 from coming into contact with the showerhead 400 . The above-described auxiliary gas GS2 may be injected through a space formed between the showerhead 400 and the isolation unit 410 . The function of the isolation unit 410 will be described later with reference to FIGS. 2 to 4 .

The plasma generator 500 serves to excite the process gas GS1 into a plasma state. The plasma generating unit 500 includes a high frequency power supply unit 510 , a first coil 521 , and a second coil 522 . The high frequency power supply unit 510 may supply high frequency RF power to the first coil 521 and the second coil 522 . The first coil 521 and the second coil 522 supplied with the high-frequency RF power may generate an induced magnetic field. The process gas GS1 injected into the process processing space 101 may be excited into a plasma state by the generated induced magnetic field.

The above has described the plasma generator 500 of the inductively coupled plasma (ICP) method, but according to some embodiments of the present invention, the plasma generator 500 is a capacitively coupled plasma (CCP). ) may depend on the method. Hereinafter, the plasma generating unit 500 of the inductively coupled plasma method will be mainly described.

The controller 600 may control injection of the process gas GS1 and the auxiliary gas GS2 . For example, the controller 600 may control the process gas valve V1 and the auxiliary gas valve V2 . For the process of the substrate W, the controller 600 may control the process gas valve V1 to open or block the first inlet line 111 . In addition, in order to determine whether the target gas and the showerhead 400 are in contact, the controller 600 may control the auxiliary gas valve V2 to open or block the second inlet line 112 .

FIG. 2 is an enlarged view of A shown in FIG. 1 , and FIGS. 3 and 4 are views for explaining the function of the side exposure space shown in FIG. 2 .

Referring to FIG. 2 , the isolation unit 410 may be disposed on a side surface of the showerhead 400 to surround the edge of the showerhead 400 .

A side exposure space 421 for exposing a side surface of the showerhead 400 to the processing space 101 may be formed between the showerhead 400 and the isolation unit 410 . Most of the area of the showerhead 400 is sealed by the isolation unit 410 , but the area of the showerhead 400 corresponding to the side exposure space 421 may be exposed to the processing space 101 .

The inner surface of the isolation unit 410 facing the side of the showerhead 400 may include an inclined surface 411 inclined toward the processing space 101 . For example, the side surface of the showerhead 400 may be a surface perpendicular to the ground, and the isolation unit 410 may have an inclined surface 411 formed to be inclined with respect to the side surface of the showerhead 400 .

Referring to FIG. 3 , the plasma particles T of the target gas may react with the showerhead 400 .

The target gas included in the process gas may be excited into a plasma state to be generated as plasma particles T. Here, the plasma particles T may be provided in the form of atoms, radicals, or ions. Hereinafter, the plasma particles T generated by excitation of the target gas into a plasma state are referred to as target plasma particles.

The target plasma particles T may react with the showerhead 400 on the lower side of the showerhead 400 or with the showerhead 400 in the side exposure space 421 . In the present invention, the target gas may be a gas containing fluorine. That is, the target plasma particle T may be a fluorine particle. The showerhead 400 may be made of a silicon (Si) material, and target plasma particles T, which are fluorine particles, may react with silicon.

2 and 4 , the side exposure space 421 may be connected to an auxiliary gas transfer pipe 422 for transferring the auxiliary gas GS2 . The auxiliary gas transfer pipe 422 may be connected to the second inlet line 112 . The auxiliary gas GS2 transferred through the second inlet line 112 and the auxiliary gas transfer pipe 422 may be injected into the process processing space 101 through the side exposure space 421 . In the present invention, the auxiliary gas GS2 may be a helium gas, but the auxiliary gas GS2 of the present invention is not limited to the helium gas.

The auxiliary gas GS2 may block the target plasma particles T from reacting with the showerhead 400 in the side exposure space 421 . As the auxiliary gas GS2 is injected, the target plasma particles T entering the side exposure space 421 are pushed out and the reaction with the showerhead 400 is blocked.

When the target plasma particles T react with the showerhead 400 , the density of the target plasma particles T in the process processing space 101 may be reduced. As described above, in the present invention, the target plasma particles T may be fluorine particles. The fluorine particles may cause a change in the density of plasma formed in the processing space 101 . As the number of fluorine particles with high electronegativity increases, electrons included in the plasma are absorbed by the fluorine particles and the density of the plasma can be lowered.

The density of the plasma may affect the process of the substrate W, in particular, may have a great effect on the process of the edge of the substrate W. Injection of the auxiliary gas GS2 may be controlled to adjust the density of plasma. For example, when the density of plasma is to be increased, the auxiliary gas GS2 may not be injected. In this case, since the target plasma particles T are reduced by reacting with the showerhead 400 , the density of plasma may be increased. Meanwhile, when the density of plasma is to be reduced, the auxiliary gas GS2 may be injected. In this case, since the target plasma particle T does not react with the showerhead 400 and absorbs electrons of the plasma, the density of the plasma may be reduced.

5 and 6 are diagrams for explaining the control of the plasma incident angle according to the state of the focus ring shown in FIG. 1 .

5 and 6 , by controlling the injection of the auxiliary gas GS2 , the plasma incident angle according to the state of the focus ring 240 may be controlled.

The focus ring 240 may be etched while the substrate W is subjected to a plasma process. As described above, the focus ring 240 controls the electric field formed at the edge of the chuck 230 while having a constant permittivity. When the focus ring 240 is etched, the overall permittivity is changed so that the shape of the electric field may be changed. . The electric field may determine the direction of the plasma entering the substrate W. As the shape of the electric field changes, the direction of the plasma entering the substrate W is changed, and a correct process for the substrate W may not be performed.

The focus ring 240 that does not form the correct electric field may be replaced with a new focus ring 240 . As the new focus ring 240 is replaced, the electric field may be restored.

On the other hand, due to the difference in the electric field formed at the beginning and the end of use of the focus ring 240 , a difference in the incident angle of the plasma may be greatly formed, and thus, a process defect may occur for the substrate W . For example, at the beginning of use of the focus ring 240 , the plasma has an incident angle toward the outside of the substrate W, while at the end of use of the focus ring 240 , the plasma has an incident angle toward the center of the substrate W. that you can have

The controller 600 may adjust the injection amount of the auxiliary gas GS2 according to the etching state of the focus ring 240 . For example, the controller 600 may increase the injection amount of the auxiliary gas GS2 at the end of the use of the focus ring 240 compared to the initial use of the focus ring 240 .

At the initial stage of use when the focus ring 240 is not etched or etched, the control unit 600 may prevent the auxiliary gas GS2 from being injected or allow a relatively small amount of the auxiliary gas GS2 to be injected. In this case, as the target plasma particles T react with the showerhead 400 , the density of plasma may increase. And, as the density of the plasma increases, as shown in FIG. 5 , the incident angle of the plasma toward the outside of the substrate W may be adjusted to face the substrate W. As shown in FIG.

At the end of use, when the focus ring 240 is etched to a significant extent, the controller 600 may cause the auxiliary gas GS2 to be injected or a relatively large amount of the auxiliary gas GS2 to be injected. In this case, the density of the plasma may be reduced while the target plasma particles T do not react with the showerhead 400 . And, as the density of the plasma is reduced, as shown in FIG. 6 , the incident angle of the plasma toward the center of the substrate W may be adjusted to face the substrate W. As shown in FIG.

Although embodiments of the present invention have been described with reference to the above and the accompanying drawings, those of ordinary skill in the art to which the present invention pertains can practice the present invention in other specific forms without changing its technical spirit or essential features. You can understand that there is Therefore, it should be understood that the embodiments described above are illustrative in all respects and not restrictive.

10: substrate processing apparatus 100: process chamber
110: process gas inlet 200: substrate support
210: base plate 220: main body
230: chuck 240: focus ring
250: ring support 310: process gas tank
320: auxiliary gas tank 400: showerhead
410: isolation part 411: inclined part
421: side exposure space 422: auxiliary gas delivery pipe
500: plasma generator 510: high-frequency power supply
521, 522: coil 600: control unit

Claims (9)

a process chamber providing a process space for the substrate;
a substrate support for supporting the substrate;
a showerhead that injects a process gas to the substrate; and
It is disposed on the side of the showerhead and includes an isolation part surrounding the edge of the showerhead,
A side exposure space for exposing a side surface of the showerhead to the processing space is formed between the showerhead and the isolation unit. According to claim 1,
Further comprising a plasma generator for exciting the process gas into a plasma state,
The plasma particles generated by excitation of the target gas included in the process gas into a plasma state do not react with the showerhead in the side exposure space, so that the density in the process processing space is reduced. 3. The method of claim 2,
The target gas is a substrate processing apparatus including a gas containing fluorine. According to claim 1,
and an inner surface of the isolation unit facing the side surface of the showerhead includes an inclined surface inclined toward the processing space. According to claim 1,
The side exposure space is connected to an auxiliary gas conveying pipe for conveying auxiliary gas,
The auxiliary gas transferred through the auxiliary gas transfer pipe is injected into the process processing space through the side exposure space. 6. The method of claim 5,
The auxiliary gas includes a helium gas. 6. The method of claim 5,
The substrate processing apparatus further comprising a control unit for controlling the injection of the auxiliary gas. 8. The method of claim 7,
A focus ring disposed to surround the edge of the substrate support to adjust an electric field formed at the edge of the substrate support,
The control unit controls the injection amount of the auxiliary gas according to the etched state of the focus ring. 9. The method of claim 8,
The control unit is configured to increase the injection amount of the auxiliary gas at the end of the use of the focus ring compared to the initial use of the focus ring.

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