KR20220167832A - Focus Ring and plasma device including the same - Google Patents

Abstract

The present invention relates to a focus ring and a plasma device including the same. More particularly, to a focus ring that includes: a first ring made of a first material; and a second ring made of a second material different from the first material. The first ring is detachably coupled to the second ring. When the first ring is worn, the worn first ring may be replaced with a new first ring.

Description

Focus ring and plasma device including the same {Focus Ring and plasma device including the same}

The present invention relates to a focus ring and a plasma device including the same, and more particularly, to a focus ring used for semiconductor plasma etching and a plasma device including the same.

In general, a semiconductor device is completed by repeatedly performing a manufacturing process on a silicon wafer. A semiconductor manufacturing process includes oxidation, masking, photoresist coating, etching, diffusion, and lamination processes for a wafer that is the material. In addition, processes such as washing, drying, and inspection should be performed before and after the above processes. In particular, the etching process is an important process for substantially forming a pattern on a wafer. The etching process can be largely divided into wet etching and dry etching.

The dry etching process is a process for removing exposed portions of the photoresist pattern formed after the photo process. After applying high-frequency power to the upper electrode and the lower electrode installed at a predetermined distance apart in the sealed inner space to form an electric field, and activating the reaction gas supplied into the sealed space with the electric field to make it into a plasma state, ions in the plasma state The wafer positioned on the lower electrode is etched.

Preferably, the plasma is concentrated over the entire top surface area of the wafer. To this end, a focus ring is disposed to surround the circumference of the chuck body above the lower electrode.

The focus ring concentrates an electric field formation area formed on the chuck body by application of high-frequency power to an area where a wafer is located, and the wafer is placed in the center of the area where plasma is formed and etched uniformly as a whole.

An object of the present invention is to provide a focus ring having excellent durability and a plasma device including the same.

According to the concept of the present invention, a focus ring includes a first ring made of a first material; and a second ring made of a second material different from the first material. The first ring is detachably coupled to the second ring, and when the first ring is worn, the worn first ring may be replaced with a new first ring.

According to another concept of the present invention, a plasma apparatus includes a support plate on which a substrate can be disposed; and an edge ring provided to surround an edge of the support plate. The edge ring includes a focus ring and a shield ring provided outside the focus ring, and the focus ring includes: a first ring made of a first material; and a second ring made of a second material different from the first material. The first ring is detachably coupled to the second ring, and when the first ring is worn, the worn first ring may be replaced with a new first ring.

In the focus ring according to embodiments of the present invention, since the first ring having high etch resistance is exposed to plasma instead of the second ring, durability of the focus ring may be improved. Since the second ring uses a cheaper material than the first ring, economic efficiency of the focus ring may be improved. Since the first ring is detachably coupled to the second ring, the first ring worn by exposure to the plasma may be replaced with a new first ring. Accordingly, economic efficiency of the focus ring may be further improved.

1 is a diagram schematically illustrating a plasma apparatus according to embodiments of the present invention.
FIG. 2 is an enlarged cross-sectional view of region M of FIG. 1 for explaining an edge ring according to embodiments of the present invention.
3 is an exploded perspective view for explaining a focus ring according to embodiments of the present invention.
4 is a cross-sectional view showing a cross section of the focus ring of FIG. 3 .
5 to 7 are cross-sectional views illustrating a method of replacing a first ring according to an embodiment of the present invention.
8 is a cross-sectional view showing a cross section of a focus ring according to another embodiment of the present invention.
9 is a cross-sectional view showing a cross section of a focus ring according to another embodiment of the present invention.
10 to 12 are cross-sectional views illustrating a method of replacing a first ring according to another embodiment of the present invention.
13 is a cross-sectional view showing a cross section of a focus ring according to another embodiment of the present invention.

Advantages and features of the present invention, and methods of achieving them, will become clear with reference to the detailed description of the following embodiments taken in conjunction with the accompanying drawings. However, the present invention is not limited to the embodiments disclosed below, but may be implemented in various different forms, and only the present embodiments allow the disclosure of the present invention to be complete, and the common knowledge in the art to which the present invention belongs. It is provided to fully inform the holder of the scope of the invention, and the present invention is only defined by the scope of the claims. Like reference numbers designate like elements throughout the specification.

Terminology used herein is for describing the embodiments and is not intended to limit the present invention. In this specification, singular forms also include plural forms unless specifically stated otherwise in a phrase. As used herein, 'comprises' and/or 'comprising' refers to the presence of one or more other elements, steps, operations and/or devices mentioned. or do not rule out additions. Hereinafter, embodiments of the present invention will be described in detail.

As an embodiment of the present invention, a plasma apparatus for processing a substrate by generating plasma in an inductively coupled plasma (ICP) method will be described. However, the present invention is not limited thereto, and can be applied to various types of devices for processing substrates using plasma, such as a capacitively coupled plasma (CCP) method or a remote plasma method.

Also, in the embodiment of the present invention, an electrostatic chuck will be described as an example as a support unit. However, the present invention is not limited thereto, and the support unit may support the substrate by mechanical clamping or by vacuum.

1 is a diagram schematically illustrating a plasma apparatus according to embodiments of the present invention.

Referring to FIG. 1 , the plasma apparatus 10 may process a substrate W using plasma. For example, the plasma apparatus 10 may perform an etching process using plasma on the substrate W. The plasma apparatus 10 may include a chamber 100 , a support unit 200 , a gas supply unit 300 , a plasma source 400 and an exhaust unit 500 .

The chamber 100 may have a processing space for processing the substrate W therein. The chamber 100 may include a housing 110 and a cover 120 .

A top surface of the housing 110 may be open. That is, the inner space of the housing 110 may be open. The inner space of the housing 110 may serve as a processing space in which a substrate processing process is performed. The housing 110 may include a metal material. For example, the housing 110 may include aluminum. Housing 110 may be grounded.

An exhaust hole 102 may be provided on the bottom surface of the housing 110 . The exhaust hole 102 may be connected to the exhaust line 151 . Reaction by-products generated during the process and gas remaining in the inner space of the housing 110 may be discharged to the outside through the exhaust line 151 . The inside of the housing 110 may be reduced to a predetermined pressure by the exhausting process.

The cover 120 may cover the open upper surface of the housing 110 . The cover 120 has a plate shape and can seal the inner space of the housing 110 . The cover 120 may include a dielectric substance window.

A liner 130 may be provided inside the housing 110 . The liner 130 may have an inner space with open top and bottom surfaces. In other words, the liner 130 may have a cylindrical shape. The liner 130 may have a radius corresponding to the inner surface of the housing 110 . The liner 130 may extend downward along the inner surface of the housing 110 .

The liner 130 may include a support ring 131 on top thereof. The support ring 131 has a ring shape and may protrude outward from the liner 130 along the circumference of the liner 130 . The support ring 131 may be provided on the top of the housing 110 to support the liner 130 .

The liner 130 may include the same material as the housing 110 . For example, the liner 130 may include aluminum. The liner 130 may protect the inner surface of the housing 110 . For example, an arc discharge may be generated inside the chamber 100 while the process gas is excited. Arc discharges can damage peripheral devices. The liner 130 may protect the inner surface of the housing 110 from being damaged by an arc discharge. In addition, reaction by-products generated during the substrate treatment process may be prevented from being deposited on the inner wall of the housing 110 . The liner 130 is cheaper than the housing 110 and can be easily replaced. Accordingly, when the liner 130 is damaged due to arc discharge, the damaged liner 130 may be replaced with a new liner 130 .

The support unit 200 may support the substrate W within the processing space inside the chamber 100 . For example, the support unit 200 may be disposed inside the housing 110 . The support unit 200 may be provided in an electrostatic chuck method that adsorbs the substrate W using electrostatic force. As another example, the support unit 200 may support the substrate W in various ways such as mechanical clamping. Hereinafter, the support unit 200 provided in an electrostatic chuck method will be described.

The support unit 200 may include chucks 220 , 230 , and 250 and an edge ring 240 . The chucks 220 , 230 , and 250 may support the substrate W during the process. The chucks 220 , 230 , and 250 may include a support plate 220 , a passage forming plate 230 , and an insulating plate 250 .

The support plate 220 may be positioned above the support unit 200 . The support plate 220 may be provided with a disk-shaped dielectric substance. For example, the support plate 220 may include quartz. A substrate W may be disposed on an upper surface of the support plate 220 . The upper surface of the support plate 220 may have a radius smaller than that of the substrate (W). A first supply passage 221 used as a passage through which heat transfer gas is supplied to the bottom surface of the substrate W may be provided on the support plate 220 . The electrostatic electrode 223 and the heater 225 may be buried in the support plate 220 .

The electrostatic electrode 223 may be positioned on the heater 225 . The electrostatic electrode 223 may be electrically connected to the first lower power source 223a. An electrostatic force acts between the electrostatic electrode 223 and the substrate W by the current applied to the electrostatic electrode 223 , and the substrate W may be adsorbed to the support plate 220 by the electrostatic force.

The heater 225 may be electrically connected to the second lower power source 225a. The heater 225 may generate heat by resisting a current applied from the second lower power source 225a. The generated heat may be transferred to the substrate W through the support plate 220 . The substrate W may be maintained at a set temperature by heat generated by the heater 225 . The heater 225 may include a spiral coil.

A flow path forming plate 230 may be provided below the support plate 220 . A bottom surface of the support plate 220 and an upper surface of the flow path forming plate 230 may be bonded to each other by an adhesive 236 . A first circulation passage 231 , a second circulation passage 232 , and a second supply passage 233 may be provided in the passage forming plate 230 . The first circulation passage 231 may serve as a passage through which heat transfer gas circulates. The second circulation passage 232 may serve as a passage through which the cooling fluid circulates. The second supply passage 233 may connect the first circulation passage 231 and the first supply passage 221 to each other. For example, the passage forming plate 230 may include quartz.

In one embodiment, the first circulation passage 231 may be provided in a spiral shape inside the passage forming plate 230 . In another embodiment, the first circulation passage 231 may include ring-shaped passages having different radii. The ring-shaped passages may be arranged to have the same central axis.

The first circulation passage 231 may be connected to the heat transfer medium storage unit 231a through a heat transfer medium supply line 231b. A heat transfer medium may be stored in the heat transfer medium storage unit 231a. The heat transfer medium may contain an inert gas. In one embodiment, the heat transfer medium may include helium (He) gas. The helium gas is supplied to the first circulation passage 231 through the supply line 231b and sequentially passed through the second supply passage 233 and the first supply passage 221 to be supplied to the bottom surface of the substrate W. can The helium gas may serve as a medium to help heat exchange between the substrate W and the support plate 220 . Accordingly, the temperature of the entire substrate W may be uniform.

The second circulation passage 232 may be connected to the cooling fluid storage unit 232a through a cooling fluid supply line 232c. A cooling fluid may be stored in the cooling fluid storage unit 232a. A cooler 232b may be provided in the cooling fluid storage unit 232a. The cooler 232b may cool the cooling fluid to a predetermined temperature. Alternatively, the cooler 232b may be installed on the cooling fluid supply line 232c. The cooling fluid supplied to the second circulation passage 232 through the cooling fluid supply line 232c may circulate along the second circulation passage 232 and cool the passage forming plate 230 . While the passage forming plate 230 is cooled, the support plate 220 and the substrate W may be cooled together to maintain the substrate W at a predetermined temperature. For the reasons described above, in general, the lower portion of the edge ring 240 may have a lower temperature than the upper portion.

An insulating plate 250 may be provided under the passage forming plate 230 . The insulating plate 250 may include an insulating material, and may electrically insulate the passage forming plate 230 and the lower cover 270 from each other.

A lower cover 270 may be provided under the support unit 200 . The lower cover 270 may be vertically spaced apart from the bottom of the housing 110 . The lower cover 270 may have an inner space with an open upper surface. An upper surface of the lower cover 270 may be covered by the insulating plate 250 . Therefore, the outer radius of the cross section of the lower cover 270 may be provided with the same length as the outer radius of the insulating plate 250 . Lift pins may be located in the inner space of the lower cover 270 to receive the transported substrate W from an external transport member and place it on the support plate 220 .

The lower cover 270 may include a connecting member 273 . The connecting member 273 may connect the outer surface of the lower cover 270 and the inner wall of the housing 110 to each other. A plurality of connection members 273 may be provided on the outer surface of the lower cover 270 at regular intervals. The connection member 273 may support the support unit 200 . In addition, the connecting member 273 may be connected to the inner wall of the housing 110 so that the lower cover 270 is grounded. A first power line 223c connected to the first lower power supply 223a, a second power line 225c connected to the second lower power supply 225a, and a heat transfer medium supply line connected to the heat transfer medium storage unit 231a ( 231b) and the cooling fluid supply line 232c connected to the cooling fluid storage unit 232a may extend into the lower cover 270 through the inner space of the connecting member 273.

The gas supply unit 300 may supply process gas to a processing space inside the chamber 100 . The gas supply unit 300 may include a gas supply nozzle 310 , a gas supply line 320 , and a gas storage unit 330 . The gas supply nozzle 310 may be provided in the central portion of the cover 120 . An injection hole may be formed on the bottom surface of the gas supply nozzle 310 . A process gas may be supplied into the chamber 100 through the injection hole.

The gas supply line 320 may connect the gas supply nozzle 310 and the gas storage unit 330 to each other. The gas supply line 320 may supply process gas stored in the gas storage unit 330 to the gas supply nozzle 310 . A valve 321 may be provided in the gas supply line 320 . The valve 321 opens and closes the gas supply line 320 and can adjust the flow rate of process gas supplied through the gas supply line 320 .

The plasma source 400 may generate plasma from a process gas supplied into the chamber 100 . The plasma source 400 may be provided outside the processing space of the chamber 100 . In one embodiment, an inductively coupled plasma (ICP) source may be used as the plasma source 400 . The plasma source 400 may include an antenna room 410, an antenna 420, and a plasma power source 430.

The antenna chamber 410 may have a cylindrical shape with an open bottom. The antenna chamber 410 may have a diameter corresponding to that of the chamber 100 . The lower end of the antenna chamber 410 may be detachably provided from the cover 120 .

The antenna 420 may be disposed inside the antenna room 410 . The antenna 420 may have a spiral coil shape. The antenna 420 may be connected to the plasma power source 430 . The antenna 420 may receive power from the plasma power source 430 . The plasma power source 430 may be located outside the chamber 100 . The antenna 420 to which power is applied may form an electromagnetic field in the processing space of the chamber 100 . The process gas may be excited into a plasma state by an electromagnetic field.

The exhaust unit 500 may be provided between the inner wall of the housing 110 and the support unit 200 . The exhaust unit 500 may include an exhaust plate 510 in which a through hole 511 is formed. The exhaust plate 510 may have an annular ring shape. A plurality of through holes 511 may be provided in the exhaust plate 510 . The process gas provided in the housing 110 may pass through the through holes 511 of the exhaust plate 510 and be exhausted to the exhaust hole 102 . The flow of processing gas may be controlled according to the shape of the exhaust plate 510 and the through holes 511 .

FIG. 2 is an enlarged cross-sectional view of region M of FIG. 1 for explaining an edge ring according to embodiments of the present invention.

Referring to FIGS. 1 and 2 , the edge ring 240 may be disposed on an edge area of the support unit 200 . The edge ring 240 may have a ring shape and may be provided to surround an edge of the support plate 220 . For example, the edge ring 240 may be disposed along the circumference of the support plate 220 .

The edge ring 240 may control an interface between a sheath and/or plasma. The edge ring 240 may include a focus ring FCR and a shield ring SHR.

The focus ring FCR includes a first ring RIN1 positioned above the focus ring, a second ring RIN2 positioned below the focus ring, and a third ring between the first ring RIN1 and the second ring RIN2. (RIN3). The third ring RIN3 may be stacked on the second ring RIN2 and coupled to the second ring RIN2. The first ring RIN1 may be stacked on the third ring RIN3 and coupled to the third ring RIN3. For example, the maximum thickness of the focus ring FCR may be 2 mm to 20 mm, but is not limited thereto.

An upper surface of the first ring RIN1 may be exposed. An upper surface of the first ring RIN1 may include a support surface SUS and an uppermost surface TTS. The support surface SUS is provided at the same height as the upper surface of the support plate 220 and may contact the bottom surface of the edge of the substrate W. In another embodiment, the support surface SUS of the first ring RIN1 may be provided lower than the top surface of the support plate 220 by a predetermined dimension, and thus the bottom surface of the edge of the substrate W and the support surface SUS ) may be spaced apart from each other at predetermined intervals.

The top surface TTS of the first ring RIN1 may be higher than the support surface SUS. Due to the difference in height between the support surface SUS and the uppermost surface TTS, the interface of the sheath and the plasma and the electric field can be adjusted. As a result, the focus ring FCR may induce plasma to be focused on the substrate W.

The second ring RIN2 may constitute a lower structure of the focus ring FCR. The second ring RIN2 may include a material different from that of the first ring RIN1. For example, the first ring RIN1 may include silicon carbide (SiC), and the second ring RIN2 may include silicon (Si). Silicon (Si) is less expensive than silicon carbide (SiC). Compared to the entire focus ring FCR made of silicon carbide (SiC), the focus ring FCR of the present invention is economical because only the first ring RIN1 exposed to the outside is made of silicon carbide (SiC).

The third ring RIN3 is interposed between the first ring RIN1 and the second ring RIN2 to couple them to each other. The third ring RIN3 may include a material different from that of the first ring RIN1. The third ring RIN3 may include the same material as the second ring RIN2 or a different material. For example, the third ring RIN3 may include silicon (Si), boron carbide, or a combination thereof. Boron carbide may include at least one selected from the group consisting of B2C, B3C, B4C, B5C, B13C2, B13C3, and B50C2. The third ring RIN3 may include a material having properties similar to those of the first and second rings RIN1 and RIN2, and may be more economical than silicon carbide, which is the first ring RIN1. Adhesive materials may be provided between the third ring RIN3 and the first ring RIN1 and between the third ring RIN3 and the second ring RIN2, respectively, which will be described later.

A shield ring SHR may be provided outside the focus ring FCR. The shield ring SHR may have a ring shape surrounding the outside of the focus ring FCR. The shielding ring SHR may prevent direct exposure of the side surface of the focus ring FCR to plasma or plasma from being introduced into the side surface of the focus ring FCR. For example, the shield ring SHR may include quartz.

In another embodiment of the present invention, although not shown, a coupler may be further provided under the edge ring 240 . The coupler may fix the edge ring 240 on the flow path forming plate 230 . The coupler may include a material having high thermal conductivity. As an example, the coupler may include a metal such as aluminum. The coupler may be bonded to the upper surface of the passage forming plate 230 by using a thermally conductive adhesive. The edge ring 240 may be bonded to the upper surface of the coupler using a thermally conductive adhesive. For example, the thermally conductive adhesive may include a silicon pad.

3 is an exploded perspective view for explaining a focus ring according to embodiments of the present invention. 4 is a cross-sectional view showing a cross section of the focus ring of FIG. 3 .

Referring to FIGS. 3 and 4 , the focus ring FCR may include a first ring RIN1 , a second ring RIN2 , and a third ring RIN3 . The third ring RIN3 may be interposed between the first and second rings RIN1 and RIN2. The first ring RIN1 may have a ring shape with the line C-C' as a central axis. The second ring RIN2 may have a ring shape with the line C-C' as a central axis. The third ring RIN3 may have a ring shape with the line C-C′ as a central axis. For example, the first ring RIN1 may include silicon carbide (SiC), the second ring RIN2 may include silicon (Si), and the third ring RIN3 may include silicon (Si) or It may contain boron carbide.

The focus ring FCR may further include a first adhesive layer ADL and a second adhesive layer RLL. The first adhesive layer ADL may be interposed between the first ring RIN1 and the third ring RIN3 to adhere them to each other. The second adhesive layer RLL may be interposed between the second and third rings RIN2 and RIN3 to adhere them to each other. Each of the first adhesive layer ADL and the second adhesive layer RLL may have a ring shape with the line C-C' as a central axis.

The third ring RIN3 may include a first surface SU1 and a second surface SU2 opposite to the first surface SU1. The first surface SU1 may be a top surface of the third ring RIN3, and the second surface SU2 may be a bottom surface of the third ring RIN3.

The first adhesive layer ADL may be interposed between the first surface SU1 of the third ring RIN3 and the bottom surface BS of the first ring RIN1 to adhere them to each other. The second adhesive layer RLL may be interposed between the second surface SU2 of the third ring RIN3 and the upper surface TS of the second ring RIN2 to adhere them to each other.

In one embodiment of the present invention, the adhesive force of the second adhesive layer RLL may be smaller than that of the first adhesive layer ADL. In other words, the adhesive force between the first surface SU1 of the third ring RIN3 and the bottom surface BS of the first ring RIN1 is It may be greater than the adhesive force between the top surfaces TS of the ring RIN2.

Each of the first adhesive layer ADL and the second adhesive layer RLL according to the present embodiment may adhere the two surfaces between the two surfaces. However, the adhesive strength of the second adhesive layer RLL to adhere the two surfaces may be less than the adhesive strength of the first adhesive layer ADL to adhere the two surfaces. For example, the first adhesive layer ADL can firmly and semi-permanently bond the two surfaces, but the second adhesive layer RLL can only bond the two surfaces to the extent that they are fixed. That is, the second adhesive layer RLL may impart only enough adhesive strength to allow the two surfaces to be separated by an external force. The second adhesive layer RLL may be a release layer that bonds two surfaces in a detachable manner.

Since the second adhesive layer RLL has a smaller adhesive force than the first adhesive layer ADL and functions as a release layer, the third ring RIN3 may be detachably coupled to the second ring RIN2. Since the first ring RIN1 is fixed to the third ring RIN3, as a result, the first ring RIN1 can be detachably coupled to the second ring RIN2 through the third ring RIN3.

In another embodiment of the present invention, the second adhesive layer RLL may have substantially the same adhesive strength as that of the first adhesive layer ADL. In other words, the adhesive force between the first surface SU1 of the third ring RIN3 and the bottom surface BS of the first ring RIN1 is It may be the same as the adhesive force between the top surface TS of the ring RIN2.

Each of the first adhesive layer ADL and the second adhesive layer RLL according to the present embodiment may adhere the two surfaces between the two surfaces. Under the same temperature, the adhesive strength of the second adhesive layer RLL to adhere the two surfaces and the adhesive strength of the first adhesive layer ADL to adhere the two surfaces may be the same. For example, each of the first and second adhesive layers ADL and RLL may firmly and semi-permanently couple the two surfaces.

As will be described later, when heat is locally applied only to the second adhesive layer RLL excluding the first adhesive layer ADL, the second adhesive layer RLL melts and the adhesive strength of the second adhesive layer RLL increases with that of the first adhesive layer ADL. may be less than the adhesive force. That is, since heat is selectively transferred only to the second adhesive layer RLL, the second adhesive layer RLL may have only enough adhesive strength to separate the two surfaces by an external force. As a result, the second adhesive layer RLL may be changed into a release layer by heat.

The second adhesive layer RLL is the same adhesive layer as the first adhesive layer ADL, but may be changed into a release layer by selectively applying heat as needed. As a result, the third ring RIN3 may be detachably coupled to the second ring RIN2. Since the first ring RIN1 is fixed to the third ring RIN3 by the first adhesive layer ADL, as a result, the first ring RIN1 is attached to the second ring RIN2 through the third ring RIN3. It can be detachably coupled.

Each of the first adhesive layer ADL and the second adhesive layer RLL may include a material capable of adhering the first or second rings RIN1 and RIN2 and the third ring RIN3 without limitation. For example, each of the first and second adhesive layers ADL and RLL may include a silicone compound (eg, siloxane) as a silicone-based adhesive. As another example, each of the first and second adhesive layers ADL and RLL may include a (meth)acrylic acid ester monomer having an alkyl group having 1 to 14 carbon atoms as an acrylate-based adhesive. As another example, each of the first and second adhesive layers ADL and RLL may include polyvinylidene fluoride (PVdF) as a fluorine-based adhesive.

As in the first embodiment described above, when the first and second adhesive layers ADL and RLL have different adhesive strengths, the second adhesive layer RLL may have a material or composition different from that of the first adhesive layer ADL. When the first and second adhesive layers ADL and RLL have the same adhesive strength as in the second embodiment described above, the first and second adhesive layers ADL and RLL may include the same adhesive. Each of the first adhesive layer ADL and the second adhesive layer RLL may be in the form of a cured thin adhesive film or may be in the form of a thin film.

The second ring RIN2 may include a portion RIN2a that protrudes more in the first direction D1 than the first and third rings RIN1 and RIN3 . The protruding part RIN2a of the second ring RIN2 may be positioned outside the first and third rings RIN1 and RIN3. The protruding portion RIN2a may include a first mounting surface MTS1 and a second mounting surface MTS2. The first mounting surface MTS1 and the second mounting surface MTS2 may be exposed to the outside without being covered by the first ring RIN1. The shielding ring SHR described above with reference to FIG. 2 may be provided on the first mounting surface MTS1 and the second mounting surface MTS2 .

'Located inside' used in this specification may mean located closer to the line C-C' (see FIG. 3). As used herein, 'located outside' may mean located farther from the C-C' line.

The upper surface of the first ring RIN1 may include a support surface SUS, an uppermost surface TTS, and an inclined surface ICS connecting them. The support surface SUS may be located inside the focus ring FCR, and the top surface TTS may be located outside the focus ring FCR. The inclined surface ICS may obliquely extend from the support surface SUS to the uppermost surface TTS.

As described above with reference to FIG. 2 , the support surface SUS may seat the substrate W. The top surface TTS may be located higher than the support surface SUS. The inclined surface ICS connects the support surface SUS and the uppermost surface TTS, and the interface between the sheath and the plasma and the electric field can be controlled through the inclined surface ICS. In other words, the inclined surface ICS may induce plasma to be concentrated on the substrate W.

When the process using the above-described plasma device of FIG. 1 is performed, the focus ring FCR may have a thickness gradually reduced as an upper portion thereof is etched by plasma. When the top of the focus ring FCR is etched and thinned, the interface between the sheath and the plasma on the outer region of the substrate W may be changed. This may affect the plasma treatment of the substrate W. Therefore, when the focus ring FCR becomes thinner than a certain thickness, it must be replaced.

In the focus ring FCR according to example embodiments, the first ring RIN1 may be provided on the second ring RIN2 to cover the second ring RIN2. Accordingly, only the first ring RIN1 may be exposed to the plasma, and the second ring RIN2 may not be exposed to the plasma due to the first ring RIN1.

Compared to the first ring RIN1 (eg, silicon carbide), the cost of the second ring RIN2, eg, silicon, may be low, but may have low etching resistance to plasma. According to embodiments of the present invention, only the first ring RIN1 having high etching resistance to plasma may be exposed to the plasma, and the second ring RIN2 may remain intact without being etched by the plasma. As a result, the focus ring FCR of the present invention may have high etching resistance to plasma through the first ring RIN1, and thus, the replacement cycle of the focus ring FCR may be increased. In addition, since the second and third rings RIN2 and RIN3 occupy about half of the total volume of the focus ring FCR, the focus ring FCR of the present invention can be economically manufactured.

In the focus ring FCR according to example embodiments, the first ring RIN1 worn (or etched) by exposure to plasma may be replaced with a new first ring RIN1. Hereinafter, a method of replacing the first ring RIN1 will be described in detail with reference to FIGS. 5 to 7 .

5 to 7 are cross-sectional views illustrating a method of replacing a first ring according to an embodiment of the present invention. Referring to FIG. 5 , the maximum thickness of the unused focus ring FCR may be the first thickness TI1 . As described above, when the focus ring FCR is mounted in the plasma apparatus of FIG. 1 and continuously exposed to plasma, the first ring RIN1 may be etched by the plasma and gradually lower in height.

Due to the worn first ring RIN1, the maximum thickness of the used focus ring FCR may have a second thickness TI2. The second thickness TI2 may be smaller than the first thickness TI1. When the second thickness TI2 becomes smaller than the predetermined thickness, the first ring RIN1 is no longer usable and must be replaced.

Referring to FIG. 6 , as described above, the first ring RIN1 may be detachably coupled to the second ring RIN2 through the third ring RIN3. In one embodiment of the present invention, since the adhesive force between the third ring RIN3 and the second ring RIN2 is smaller than the adhesive force between the third ring RIN3 and the first ring RIN1, the worn first ring When an external force is applied to RIN1, the first ring RIN1 may be separated from the second ring RIN2 together with the third ring RIN3. Accordingly, only the intact second ring RIN2 may remain.

In another embodiment of the present invention, heat is selectively applied to the second adhesive layer RLL between the third ring RIN3 and the second ring RIN2 to melt the second adhesive layer RLL, thereby forming the second adhesive layer RLL. adhesion may be weakened. Accordingly, when an external force is applied to the worn first ring RIN1, the first ring RIN1 may be separated from the second ring RIN2 together with the third ring RIN3.

Referring to FIG. 7 , a stacked ring of a new first ring RIN1 and a third ring RIN3 may be provided on the second ring RIN2. By coupling the stacked ring to the second ring RIN2, a new focus ring FCR may be prepared.

According to embodiments of the present invention, the second ring RIN2 may be recycled by replacing the worn first ring RIN1 with a new first ring RIN1 without discarding the second ring RIN2. . Accordingly, the economic efficiency of the focus ring FCR of the present invention may be improved.

8 is a cross-sectional view showing a cross section of a focus ring according to another embodiment of the present invention. In this embodiment, detailed descriptions of technical features overlapping with those previously described with reference to FIGS. 3 and 4 will be omitted, and differences will be described in detail.

Referring to FIG. 8 , the first ring RIN1 may include a first recess region RS1 recessed upward from the bottom surface BS thereof. The first recess region RS1 may be a circular trench extending along the first ring RIN1 along line C-C' as a central axis. The second ring RIN2 may include a second recess region RS2 recessed downward from the upper surface TS thereof. The second recess region RS2 may be a circular trench extending along the second ring RIN2 along line C-C′ as a central axis.

The first recess area RS1 and the second recess area RS2 may vertically overlap each other. A width of the first recess region RS1 in the first direction D1 and a width of the second recess region RS2 in the first direction D1 may be substantially equal to each other. The depth of the first recess region RS1 and the depth of the second recess region RS2 may be the same as or different from each other.

The first ring RIN1 is provided on the second ring RIN2 so that the bottom surface BS of the first ring RIN1 may directly contact the top surface TS of the second ring RIN2. When the first ring RIN1 and the second ring RIN2 contact each other, the first recess region RS1 and the second recess region RS2 communicate with each other to form an empty internal space inside the focus ring FCR. can be formed The inner space may be a circular empty space extending along line C-C′ as a central axis.

A third ring RIN3 may be provided in an inner space between the first ring RIN1 and the second ring RIN2. The third ring RIN3 may be provided in the first and second recess regions RS1 and RS2. The third ring RIN3 may extend along the inner space along line C-C′ as a central axis.

The thickness of the third ring RIN3 may be substantially equal to the sum of the depths of the first recessed region RS1 and the depths of the second recessed region RS2. A width of the third ring RIN3 in the first direction D1 may be smaller than that of the first and second recess regions RS1 and RS2 .

Adhesive layers ADL may be provided on both sides of the third ring RIN3, respectively. The adhesive layer ADL may couple the third ring RIN3 to the inner walls of the first and second recess regions RS1 and RS2. In other words, the first ring RIN1 and the second ring RIN2 may be coupled to each other through the third ring RIN3.

The first ring RIN1 may be detachably coupled to the second ring RIN2 through the third ring RIN3. Since the first ring RIN1 and the second ring RIN2 are coupled to each other using the adhesive layer ADL provided locally only on both sidewalls of the third ring RIN3, the adhesive force between them may be relatively weak. . Accordingly, the first ring RIN1 may be separated from the second ring RIN2 by an external force. As described above with reference to FIGS. 5 to 7 , when the first ring RIN1 is worn out, it may be replaced with a new first ring RIN1.

9 is a cross-sectional view showing a cross section of a focus ring according to another embodiment of the present invention. In this embodiment, detailed descriptions of technical features overlapping with those previously described with reference to FIGS. 3 and 4 will be omitted, and differences will be described in detail.

Referring to FIG. 9 , the focus ring FCR includes a first ring RIN1 and a second ring RIN2, and the third ring RIN3 may be omitted. The first ring RIN1 is directly provided on the second ring RIN2, so that the bottom surface of the first ring RIN1 may directly contact the top surface of the second ring RIN2.

The focus ring FCR may further include a plurality of fastening members FTM. The fastening member FTM may detachably couple the first ring RIN1 and the second ring RIN2 to each other. As the fastening member FTM, any member capable of mechanically detachably coupling the first ring RIN1 and the second ring RIN2 to each other may be used without limitation. According to this embodiment, each of the fastening members FTM may be a bolt.

The second ring RIN2 may include a plurality of through holes TRH vertically passing through the second ring RIN2 . The first ring RIN1 may include a plurality of fastening holes FTH extending vertically from its bottom surface toward its top surface. The fastening hole FTH may have a shape of a groove dug to a predetermined depth without completely penetrating the first ring RIN1.

The through holes TRH of the second ring RIN2 and the fastening holes FTH of the first ring RIN1 may vertically overlap each other. The through hole TRH and the fastening hole FTH communicate with each other to provide a space into which the fastening member FTM can be inserted.

A screw thread TRD may be provided on at least one portion of the fastening member FTM. The fastening member FTM may be provided in the through hole TRH and the fastening hole FTH and may be physically coupled to the first and second rings RIN1 and RIN2 through the screw thread TRD.

Since the fastening member FTM is provided inside the focus ring FCR exposed to plasma, the material constituting the fastening member FTM may be important. The fastening member FTM may include an insulating material that does not soften while maintaining its shape even at a temperature of 200°C to 500°C. The dielectric constant of the fastening member (FTM) may be 3 to 15. The fastening member FTM may have a tensile strength of 20 MPa to 50 MPa at a temperature of 260°C. The fastening member FTM may have a linear expansion coefficient of 20 μm/m/° C. to 60 μm/m/° C. when the temperature is raised from 23° C. to 260° C. For example, the fastening member FTM may include a polyimide-based polymer.

10 to 12 are cross-sectional views illustrating a method of replacing a first ring according to another embodiment of the present invention. Referring to FIG. 10 , the maximum thickness of the unused focus ring FCR may be the first thickness TI1. When the focus ring FCR is mounted in the plasma device of FIG. 1 and continuously exposed to plasma, the first ring RIN1 may be etched by the plasma and gradually lower in height.

Due to the worn first ring RIN1, the maximum thickness of the used focus ring FCR may have a second thickness TI2. The second thickness TI2 may be smaller than the first thickness TI1. When the second thickness TI2 becomes smaller than the predetermined thickness, the first ring RIN1 is no longer usable and must be replaced.

Referring to FIG. 11 , as described above, the first ring RIN1 may be detachably coupled to the second ring RIN2 through the fastening member FTM. Specifically, all of the fastening members FTM in the focus ring FCR may be removed. When the fastening members FTM are removed, the first ring RIN1 can be easily separated from the second ring RIN2. Accordingly, only the intact second ring RIN2 may remain.

Referring to FIG. 12 , a new first ring RIN1 may be provided on the second ring RIN2. When the first ring RIN1 is accurately aligned on the second ring RIN2, the fastening holes FTH of the first ring RIN1 vertically overlap the through holes TRH of the second ring RIN2, respectively. can

When the first ring RIN1 is seated on the upper surface of the second ring RIN2, each of the fastening members FTM may be screwed into the through hole TRH and the fastening hole FTH. A new focus ring FCR may be prepared by fixing the first and second rings RIN1 and RIN2 to each other by the fastening members FTM.

According to embodiments of the present invention, the second ring RIN2 may be recycled by replacing the worn first ring RIN1 with a new first ring RIN1 without discarding the second ring RIN2. . Accordingly, the economic efficiency of the focus ring FCR of the present invention may be improved. In addition, since a heterogeneous material such as an adhesive is not used, contamination of the focus ring FCR with impurities can be prevented.

13 is a cross-sectional view showing a cross section of a focus ring according to another embodiment of the present invention. In this embodiment, detailed descriptions of technical features overlapping with those previously described with reference to FIG. 9 will be omitted, and differences will be described in detail.

Referring to FIG. 13 , each fastening member FTM may include a fixing part FTP at an upper portion thereof. In the fastening member FTM according to the present embodiment, the screw thread TRD may be omitted.

The fastening member FTM is inserted into the through hole TRH and the fastening hole FTH, and the first ring RIN1 and the second ring RIN2 may be coupled by a press-fitting method. For example, the fixing part FTP of the fastening member FTM is provided in the fastening hole FTH of the first ring RIN1, so that the fastening part FTP can attach the fastening member FTM to the first and second rings. (RIN1, RIN2) can be strongly bound. The width of the fixing part FTP may be greater than the width of the through hole TRH, and thus the fixing part FTP inserted into the fastening hole FTH may not come out again through the through hole TRH.

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

Claims (17)

A first ring made of a first material; and
Including a second ring made of a second material different from the first material,
The first ring is detachably coupled to the second ring,
A focus ring capable of replacing the worn first ring with a new first ring when the first ring is worn out.
According to claim 1,
Further comprising a third ring interposed between the first ring and the second ring,
The third ring is a focus ring that couples the first ring and the second ring in a detachable manner to each other.
According to claim 2,
An adhesive force between the third ring and the first ring is smaller than an adhesive force between the third ring and the second ring.
According to claim 2,
The third ring includes silicon (Si), boron carbide, or a combination thereof.
According to claim 2,
a first adhesive layer interposed between the first ring and the third ring; and
Further comprising a second adhesive layer interposed between the second ring and the third ring,
The first adhesive layer completely adheres the first ring and the third ring,
The second adhesive layer fixes the second ring and the third ring, but attaches them so that they can be separated from each other by an external force.
According to claim 2,
a first adhesive layer interposed between the first ring and the third ring; and
Further comprising a second adhesive layer interposed between the second ring and the third ring,
The first adhesive layer adheres the first ring and the third ring,
The second adhesive layer adheres the second ring and the third ring, and allows the second ring and the third ring to be separated from each other by heat.
According to claim 2,
The first ring includes a first recessed region recessed upward from a bottom surface thereof,
The second ring includes a second recessed region recessed downward from an upper surface thereof,
the first and second recess regions overlap each other to form an empty internal space inside the focus ring;
The third ring is a focus ring provided in the inner space.
According to claim 7,
An adhesive layer is interposed between both sides of the third ring and the first and second recess regions.
According to claim 1
The focus ring further includes a fastening member passing through the second ring and detachably coupling the first ring and the second ring to each other.
According to claim 9,
The second ring includes a through hole penetrating the inside thereof,
The first ring includes a fastening hole vertically overlapped with the through hole and dug to a predetermined depth;
The fastening member is inserted into the through hole and the fastening hole.
According to claim 9,
The fastening member includes a screw thread,
A focus ring in which the fastening member couples the first and second rings to each other through the screw thread.
According to claim 9,
The fastening member couples the first and second rings to each other in a press-fitting manner.
According to claim 9,
The fastening member is a focus ring comprising a polyimide-based polymer.
According to claim 9,
The fastening member is:
has a dielectric constant of 3 to 15;
It has a tensile strength of 20 MPa to 50 MPa at a temperature of 260 ° C,
A focus ring having a linear expansion coefficient of 20 μm/m/° C. to 60 μm/m/° C. when the temperature is raised from 23° C. to 260° C.
According to claim 1,
The first material is silicon carbide (SiC),
The second material is silicon (Si) focus ring.
a support plate on which a substrate may be placed; and
Including an edge ring provided to surround the edge of the support plate,
The edge ring includes a focus ring and a shield ring provided outside the focus ring,
The focus ring is:
A first ring made of a first material; and
Including a second ring made of a second material different from the first material,
The first ring is detachably coupled to the second ring,
A plasma device capable of replacing the worn first ring with a new first ring when the first ring is worn.
According to claim 16,
The second ring includes a portion that protrudes more outward than the first ring,
the protruding portion includes at least one mounting surface;
Plasma apparatus wherein the shielding ring is provided on the mounting surface.

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