KR102585290B1 - 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, and more specifically, to a focus ring, a first ring made of a first material; a second ring made of a second material different from the first material; and a first adhesive layer between the first ring and the second ring. The first ring is provided on the second ring and coupled to the second ring, the second ring includes a first recess area recessed downward from its upper surface, and the first ring has its It includes a first protrusion protruding downward from the bottom surface, the first protrusion is inserted into the first recess area, and the first adhesive layer is disposed on the bottom surface of the first protrusion and the bottom of the first recess area. It is interposed between.

Description

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 specifically, to a focus ring used in a semiconductor plasma etching device and a plasma device including the same.

In general, semiconductor devices are completed by repeatedly performing manufacturing processes on silicon wafers. The semiconductor manufacturing process includes oxidation, masking, photoresist application, etching, diffusion, and stacking processes on the wafer used as the material. In addition, auxiliary processes such as washing, drying, and inspection must be performed before and after the above processes. In particular, the etching process is an important process that substantially forms patterns on the wafer. The etching process can be broadly divided into wet etching and dry etching.

The dry etching process is a process to remove exposed areas of the photoresist pattern formed after the photo process. An electric field is formed by applying high-frequency power to the upper and lower electrodes installed at a predetermined distance in a sealed internal space, and the electric field activates the reaction gas supplied into the sealed space to form a plasma state, and then ions in the plasma state are activated. The wafer located on this lower electrode is etched.

It is desirable for the plasma to be concentrated on the entire upper surface area of the wafer. For this purpose, a focus ring is arranged to surround the circumference of the chuck body on the upper part of the lower electrode.

The focus ring focuses the area where the electric field is formed by applying high-frequency power, which is formed on the upper part of the chuck body, to the area where the wafer is located, and the wafer is placed at the center of the area where the plasma is formed and is etched uniformly throughout.

The purpose of the present invention is to provide a focus ring with 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; a second ring made of a second material different from the first material; And it may include a first adhesive layer between the first ring and the second ring. The first ring is provided on the second ring and coupled to the second ring, the second ring includes a first recess area recessed downward from its upper surface, and the first ring has its It includes a first protrusion protruding downward from the bottom surface, the first protrusion is inserted into the first recess area, and the first adhesive layer is disposed on the bottom surface of the first protrusion and the bottom of the first recess area. may be interposed between them.

According to another concept of the present invention, a plasma device includes a support plate on which a substrate can be placed; And it may include an edge ring provided to surround an edge of the support plate. The edge ring includes a focus ring and a shielding ring provided outside the focus ring, and the focus ring includes: a first ring made of a first material; a second ring made of a second material different from the first material; And it may include an adhesive layer between the first ring and the second ring. The first ring is provided on the second ring and coupled to the second ring, the second ring includes a recess area depressed downward from its upper surface, and the first ring has a bottom surface thereof. and a protrusion protruding downward from the protrusion, the protrusion being inserted into the recess area, and the adhesive layer may be interposed between the bottom surface of the protrusion and the bottom of the recess area.

The durability of the focus ring according to embodiments of the present invention may be improved because the first ring, which has high etching resistance, is exposed to plasma instead of the second ring. Since the second ring uses a cheaper material than the first ring, the economic efficiency of the focus ring can be improved. The first ring and the second ring can be mechanically and stably coupled using the concavo-convex structure, and the problem of the adhesive layer overflowing can be prevented.

Focus rings according to embodiments of the present invention may have a relatively small dielectric constant and relatively high thermal conductivity. Therefore, the focus ring of the present invention can be mounted inside a plasma device to improve the efficiency of the plasma process.

1 is a diagram schematically explaining a plasma device according to embodiments of the present invention.
FIG. 2 is an enlarged cross-sectional view of area M of FIG. 1 to illustrate an edge ring according to embodiments of the present invention.
Figure 3 is an exploded perspective view to explain a focus ring according to embodiments of the present invention.
FIG. 4 is a cross-sectional view showing a cross section of the focus ring of FIG. 3.
Figures 5, 6, and 7 are cross-sectional views showing a focus ring according to another embodiment of the present invention.

The advantages and features of the present invention and methods for achieving them will become clear by referring to the embodiments described in detail below along with the accompanying drawings. However, the present invention is not limited to the embodiments disclosed below and may be implemented in various different forms. The present embodiments are merely provided to ensure that the disclosure of the present invention is complete and to provide common knowledge in the technical field to which the present invention pertains. It is provided to fully inform those who have the scope of the invention, and the present invention is only defined by the scope of the claims. The same reference numerals refer to the same elements throughout the specification.

The terminology used herein is for describing embodiments and is not intended to limit the invention. As used herein, singular forms also include plural forms, unless specifically stated otherwise in the context. As used in the specification, 'comprises' and/or 'comprising' refers to the presence of one or more other components, steps, operations and/or devices. or does not rule out addition. Hereinafter, embodiments of the present invention will be described in detail.

As an embodiment of the present invention, a plasma device that processes a substrate by generating plasma using an inductively coupled plasma (ICP) method will be described. However, the present invention is not limited to this, and can be applied to various types of devices that process substrates using plasma, such as a capacitively coupled plasma (CCP: Conductively Coupled Plasma) method or a remote plasma method.

Additionally, embodiments of the present invention will be described using an electrostatic chuck as an example of a support unit. However, the present invention is not limited to this, and the support unit may support the substrate by mechanical clamping or support the substrate by vacuum.

1 is a diagram schematically explaining a plasma device according to embodiments of the present invention.

Referring to FIG. 1, the plasma device 10 can process the substrate W using plasma. For example, the plasma device 10 may perform an etching process using plasma on the substrate W. The plasma device 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 therein for processing the substrate W. Chamber 100 may include a housing 110 and a cover 120.

The housing 110 may have an open top. That is, the internal space of the housing 110 may be open. The internal space of the housing 110 may be provided as a processing space where a substrate processing process is performed. Housing 110 may include a metal material. For example, housing 110 may include aluminum. Housing 110 may be grounded.

An exhaust hole 102 may be provided on the bottom 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 internal 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 through the exhaust 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 internal space of the housing 110. Cover 120 may include a dielectric substance window.

A liner 130 may be provided inside the housing 110. The liner 130 may have an internal 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 its top. The support ring 131 has a ring shape and may protrude to the outside of the liner 130 along the circumference of the liner 130 . The support ring 131 is provided at 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, liner 130 may include aluminum. The liner 130 may protect the inner side of the housing 110. For example, in the process of exciting the process gas, an arc discharge may be generated inside the chamber 100. Arc discharge can damage peripheral devices. The liner 130 protects the inner surface of the housing 110 and can prevent the inner surface of the housing 110 from being damaged by arc discharge. Additionally, reaction by-products generated during the substrate processing process can be prevented from being deposited on the inner wall of the housing 110. The liner 130 is less expensive than the housing 110 and can be easily replaced. Accordingly, when the liner 130 is damaged due to arc discharge, the damaged liner 130 can 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 as an electrostatic chuck 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 by the 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 flow path forming plate 230, and an insulating plate 250.

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

Electrostatic electrode 223 may be located on heater 225. The electrostatic electrode 223 may be electrically connected to the first lower power source 223a. Electrostatic force acts between the electrostatic electrode 223 and the substrate W due to 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 the 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 the heat generated by the heater 225. The heater 225 may include a spiral-shaped coil.

A flow path forming plate 230 may be provided below the support plate 220. The bottom surface of the support plate 220 and the upper surface of the flow path forming plate 230 may be bonded to each other using 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 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 flow path 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 flow paths may be arranged to have the same central axis.

The first circulation flow path 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 include an inert gas. In one embodiment, the heat transfer medium may include helium (He) gas. Helium gas is supplied to the first circulation flow path 231 through the supply line 231b, and is sequentially supplied to the bottom surface of the substrate W through the second supply flow path 233 and the first supply flow path 221. You can. Helium gas may serve as a medium to aid heat exchange between the substrate W and the support plate 220. Therefore, the temperature of the substrate W may be uniform throughout.

The second circulation passage 232 may be connected to the cooling fluid storage unit 232a through a cooling fluid supply line 232c. Cooling fluid may be stored in the cooling fluid storage unit 232a. A cooler 232b may be provided within 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. As the channel forming plate 230 cools, the support plate 220 and the substrate W can be cooled together to maintain the substrate W at a predetermined temperature. For the reasons described above, generally, the temperature of the lower part of the edge ring 240 may be lower than that of the upper part.

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

A lower cover 270 may be provided below the support unit 200. The lower cover 270 may be arranged to be vertically spaced apart from the bottom of the housing 110. The lower cover 270 may have an internal space with an open upper surface. The upper surface of the lower cover 270 may be covered by an insulating plate 250. Accordingly, the outer radius of the cross section of the lower cover 270 may be provided to be the same length as the outer radius of the insulating plate 250. A lift pin may be located in the inner space of the lower cover 270 to receive the transported substrate W from an external transport member and seat 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 connecting 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. Additionally, the connection member 273 can be connected to the inner wall of the housing 110 to ground the lower cover 270. A first power line 223c connected to the first lower power source 223a, a second power line 225c connected to the second lower power source 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 connection member 273.

The gas supply unit 300 may supply process gas to the 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. 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 the 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 control the flow rate of the process gas supplied through the gas supply line 320.

The plasma source 400 may generate plasma from 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 room 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 room 410 may be provided to be detachable from the cover 120.

The antenna 420 may be placed 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. The exhaust plate 510 may be provided with a plurality of through holes 511. The process gas provided in the housing 110 may pass through the through holes 511 of the exhaust plate 510 and be exhausted through the exhaust hole 102. The flow of process gas can be controlled depending on the shape of the exhaust plate 510 and the shapes of the through holes 511.

FIG. 2 is an enlarged cross-sectional view of area M of FIG. 1 to illustrate 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 the 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 can control the interface of the sheath and/or plasma. The edge ring 240 may include a focus ring (FCR) and a shielding ring (SHR).

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

The top surface of the first ring (RIN1) may be exposed. The upper surface of the first ring (RIN1) may include a support surface (SUS) and a top surface (TTS). The support surface SUS is provided at the same height as the top surface of the support plate 220, and can be in contact with 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 upper 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 lower than the upper surface of the support plate 220. ) may be spaced apart from each other at a predetermined interval.

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

The second ring (RIN2) may form a lower structure of the focus ring (FCR). The second ring (RIN2) may include a different material from 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 cheaper than silicon carbide (SiC). Compared to the entire focus ring (FCR) made of silicon carbide (SiC), the focus ring (FCR) of the present invention can be economical because only the first ring (RIN1) exposed to the outside is made of silicon carbide (SiC).

A shielding ring (SHR) may be provided outside the focus ring (FCR). The shielding ring (SHR) may have a ring shape surrounding the outside of the focus ring (FCR). The shielding ring (SHR) can prevent the side of the focus ring (FCR) from being directly exposed to plasma or the plasma from flowing into the side of the focus ring (FCR). For example, the shielding ring (SHR) may include quartz.

In another embodiment of the present invention, although not shown, a coupler may be further provided below the edge ring 240. The coupler may secure the edge ring 240 on the flow path forming plate 230. The coupler may include a highly thermally conductive material. As an example, the coupler may include a metal such as aluminum. The coupler may be bonded to the upper surface of the flow path forming plate 230 using a heat-conducting adhesive. The edge ring 240 may be bonded to the upper surface of the coupler using a heat conductive adhesive. As an example, the heat conductive adhesive may include a silicone pad.

Figure 3 is an exploded perspective view to explain a focus ring according to embodiments of the present invention. FIG. 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 an adhesive layer ADL. The first ring (RIN1) may be provided on the second ring (RIN2) and coupled to the second ring (RIN2).

The first ring (RIN1) may have the shape of a ring with the line C-C' as its central axis. The second ring (RIN2) may have the shape of a ring with the line C-C' as its central axis. The adhesive layer (ADL) may be interposed between the first ring (RIN1) and the second ring (RIN2). The adhesive layer (ADL) may have the shape of a ring with the C-C' line as the central axis. As an example, the first ring (RIN1) may include silicon carbide (SiC), and the second ring (RIN2) may include silicon (Si).

According to this embodiment, a recess area (RS) may be provided in the upper part of the second ring (RIN2). The recess area RS may be recessed from the top surface of the second ring RIN2 toward the bottom surface of the second ring RIN2. The recess region RS may be a circular trench extending along the second ring RIN2 with line C-C' as the central axis.

The second ring RIN2 may have a first upper surface TS1 and a second upper surface TS2. The first top surface TS1 and the second top surface TS2 may be provided at the same height. A recess area RS may be located between the first upper surface TS1 and the second upper surface TS2. The bottom (RSb) of the recess area (RS) may be lower than the first and second top surfaces (TS1) and TS2.

The second ring (RIN2) may include a portion (RIN2a) that protrudes more in the first direction (D1) than the first ring (RIN1). 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.

The first ring RIN1 may have a first height HE1, that is, a thickness in the second direction D2, and the second ring RIN2 may have a second height HE2, that is, a thickness in the second direction D2. thickness). The first height HE1 may be larger or smaller than the second height HE2. For example, the first height HE1 may be 4 mm to 6 mm, and the second height HE2 may be 3.7 mm to 5.7 mm.

The focus ring FCR may have a third height HE3. The third height HE3 may be the sum of the first height HE1 and the second height HE2. The ratio of the first height HE1 to the third height HE3 may be 0.39 to 0.59, and the ratio of the second height HE2 to the third height HE3 may be 0.41 to 0.61.

The first ring (RIN1) may include a body portion (BDP) and a protruding portion (PRP) protruding downward from the body portion (BDP). The protrusion PRP may extend from the bottom surface BS1 of the body BDP to the inside of the recess region RS. In other words, the protrusion PRP may be inserted into the recess region RS. The bottom surface BS2 of the protrusion PRP may be lower than the bottom surface BS1 of the body BDP.

The protrusion PRP may have a shape corresponding to the recess area RS of the second ring RIN2. For example, the width WID1 of the protrusion PRP in the first direction D1 may be substantially equal to the width of the recess region RS in the first direction D1. For example, the width WID1 of the protrusion PRP in the first direction D1 or the width of the recess region RS in the first direction D1 may be 12 mm to 18 mm.

The maximum width WID2 of the second ring RIN2 in the first direction D1, that is, the maximum width of the focus ring FCR, may be 30 mm to 40 mm. The ratio (WID1/WID2) of the width (WID1) of the protrusion (PRP) to the width (WID2) of the second ring (RIN2) may be 0.3 to 0.6. More specifically, the ratio (WID1/WID2) of the width (WID1) of the protrusion (PRP) to the width (WID2) of the second ring (RIN2) may be 0.35 to 0.53.

If the width (WID1) of the protrusion (PRP) with respect to the width (WID2) of the second ring (RIN2) is less than 0.3, the area of the adhesive layer (ADL) is reduced so that the first ring (RIN1) and the second ring (RIN2) It may not adhere properly and may be easily detached. Additionally, as shown in Table 1, which will be described later, the thermal conductivity of the focus ring (FCR) is greatly reduced, thereby reducing the efficiency of the plasma process.

If the width (WID1) of the protrusion (PRP) with respect to the width (WID2) of the second ring (RIN2) is greater than 0.6, the size of the protrusion (PRP) of the first ring (RIN1) increases and the size of the protrusion (PRP) of the first ring (RIN1) increases. Volume may increase. In this case, the manufacturing cost of the focus ring (FCR) may increase, reducing economic feasibility. Additionally, as shown in Table 1, which will be described later, the dielectric constant of the focus ring (FCR) increases significantly, which may reduce the efficiency of the plasma process.

The protrusion length (PRL) of the protrusion (PRP) may be substantially equal to or smaller than the depth (DEP) of the recess region (RS). The protrusion length (PRL) of the protrusion (PRP) may be defined as the height difference between the bottom surface (BS1) of the body portion (BDP) and the bottom surface (BS2) of the protrusion (PRP). As an example, the protrusion length (PRL) of the protrusion (PRP) may be 0.5 mm to 1.5 mm. The height difference between the bottom surface BS1 of the body BDP and the bottom surface BS2 of the protrusion PRP may be 0.1 mm to 0.5 mm. In other words, the thickness of the adhesive layer (ADL) may be 0.1 mm to 0.3 mm.

The body portion BDP may be provided on the first and second upper surfaces TS1 and TS2 of the second ring RIN2. The bottom surface BS1 of the body BDP may directly contact the first and second top surfaces TS1 and TS2. The level of the boundary where the bottom surface BS1 of the body BDP and the first upper surface TS1 of the second ring RIN2 contact is the level of the boundary between the bottom surface BS1 of the body BDP and the second ring RIN2. The level of the boundary at which the second upper surface TS2 is in contact may be substantially the same. The bottom surface BS1 of the body BDP may be in contact with the first and second upper surfaces TS1 and TS2 of the second ring RIN2, but may not be adhered to them.

The adhesive layer (ADL) may be interposed between the protrusion (PRP) of the first ring (RIN1) and the recess region (RS) of the second ring (RIN2). More specifically, the adhesive layer (ADL) may be interposed between the bottom surface (BS2) of the protrusion (PRP) and the bottom (RSb) of the recess region (RS).

The adhesive layer (ADL) may adhere the first ring (RIN1) and the second ring (RIN2) to each other. The adhesive layer (ADL) may include a material that can adhere the first ring (RIN1) and the second ring (RIN2). For example, the adhesive layer (ADL) may include aluminum oxide and a silicon compound (eg, siloxane). The adhesive layer (ADL) may be in the form of a cured thin adhesive film, or the adhesive layer (ADL) may be in the form of a thin film.

The adhesive layer (ADL) may be provided only between the protrusion (PRP) of the first ring (RIN1) and the recess region (RS) of the second ring (RIN2). In other words, the adhesive layer (ADL) may remain only within the recess area (RS) and may not extend outside of the recess area (RS). The adhesive layer ADL may not exist between the first and second upper surfaces TS1 and TS2 of the second ring RIN2 and the bottom surface BS1 of the body BDP. The bottom surface BS2 of the protrusion PRP and the bottom RSb of the recess area RS may be adhered to each other by the adhesive layer ADL.

According to embodiments of the present invention, the adhesive layer (ADL) may be provided only in the recessed region (RS) of the second ring (RIN2). The recess area RS has a sufficient depth ( DEP) may be present. As a result, when the first ring (RIN1) and the second ring (RIN2) are bonded, the adhesive overflows and the adhesive layer (ADL) protrudes out of the focus ring (FCR), or the adhesive layer (ADL) protrudes out of the focus ring (FCR), or the adhesive layer (ADL) protrudes out of the focus ring (FCR). It is possible to prevent defects in which (RIN2) does not completely contact each other and is separated from each other by the adhesive layer (ADL). For example, the depth (DEP) of the recess region (RS) may be 0.5 mm to 2 mm.

According to embodiments of the present invention, when the first ring (RIN1) and the second ring (RIN2) are combined, the protrusion (PRP) and the recess region (RS) may be stably engaged with each other in a concavo-convex structure. As a result, the first ring (RIN1) and the second ring (RIN2) are firmly coupled to each other through the uneven structure of the protrusion (PRP) and recess region (RS) as well as the adhesive layer (ADL), and the focus ring (FCR) It can be more mechanically stable.

Additionally, since the protrusion (PRP) and the recess region (RS) are precisely engaged with each other, when the first ring (RIN1) and the second ring (RIN2) are joined, they can be accurately aligned and joined. This can prevent structural defects from occurring in the focus ring (FCR).

The upper surface of the first ring (RIN1) may include a support surface (SUS), a top 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 extend obliquely from the support surface (SUS) to the top surface (TTS).

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

As previously described with reference to FIG. 2, the support surface SUS can 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 top surface (TTS), and the interface and electric field of the sheath and plasma can be adjusted through the inclined surface (ICS). In other words, the inclined surface ICS can induce plasma to be concentrated onto the substrate W.

When performing a process using the plasma device of FIG. 1 described above, the upper portion of the focus ring (FCR) may be etched by plasma to gradually reduce its thickness. When the upper portion of the focus ring (FCR) is etched to become thinner, 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 embodiments of the present invention, the first ring (RIN1) is 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 by the first ring (RIN1).

The second ring (RIN2), for example, silicon, may be less expensive than the first ring (RIN1), for example, silicon carbide, but may have low etching resistance to plasma. According to embodiments of the present invention, only the first ring (RIN1), which has high etching resistance to plasma, is exposed to the plasma, and the second ring (RIN2) can be maintained as is without being etched by the plasma. As a result, the focus ring (FCR) of the present invention can have high etching resistance to plasma through the first ring (RIN1), and thus the replacement cycle of the focus ring (FCR) can be increased. Additionally, since the second ring (RIN2) occupies about half of the total volume of the focus ring (FCR), the focus ring (FCR) of the present invention can be manufactured economically.

In the focus ring (FCR) of the present invention, the ratio of the width (WID1) of the protrusion (PRP) of the first ring (RIN1) to the maximum width (WID2) of the focus ring (FCR) is varied to form the focus rings (embodiment) Examples 1 to 10) were produced. The first ring (RIN1) was made of silicon carbide (SiC), and the second ring (RIN2) was made of silicon (Si). The dielectric constant and thermal conductivity of the manufactured focus rings were measured and are shown in Table 1 below.

division WID1/WID2 Dielectric constant (ε) Thermal conductivity (W/m·K) Example 1 0.29 5.7 78 Example 2 0.32 4.8 78 Example 3 0.35 5.1 85 Example 4 0.38 5.21 86 Example 5 0.41 5.35 86 Example 6 0.44 5.44 86 Example 7 0.47 5.78 86 Example 8 0.50 6.03 88 Example 9 0.53 6.66 89 Example 10 0.55 8.56 89

Referring to Table 1, the dielectric constant was relatively small when the ratio of WID1/WID2 was in the range of 0.35 (35%) to 0.53 (53%) (Examples 3 to 9), and when it was out of that range, the dielectric constant It was confirmed that there was a significant increase (Example 10). Meanwhile, the thermal conductivity was relatively high when the ratio of WID1/WID2 was in the range of 0.35 (35%) to 0.53 (53%), and it was confirmed that the thermal conductivity was significantly reduced when it was outside the range (Examples 1 and 2 ).

That is, as the width (WID1) of the protrusion (PRP) of the first ring (RIN1) becomes relatively larger, the dielectric constant increases. In particular, when it exceeds a certain value as in Example 10, a problem of a sharp increase in the dielectric constant occurs. You can. Conversely, as the width (WID1) of the protrusion (PRP) of the first ring (RIN1) becomes relatively smaller, the dielectric constant decreases, but the thermal conductivity may also decrease. In particular, when the width (WID1) of the protrusion (PRP) is smaller than a certain ratio as in Examples 1 and 2, a problem in which thermal conductivity rapidly increases may occur.

As a result, as in Examples 3 to 9 of the present invention, the focus ring (FCR) secures a relatively small dielectric constant when the ratio of WID1 / WID2 is in the range of 0.35 (35%) to 0.53 (53%) At the same time, relatively high thermal conductivity can be secured. The focus ring (FCR) according to the present invention can improve plasma process efficiency inside a plasma device by having a small dielectric constant and high thermal conductivity.

In the focus ring (FCR) of the present invention, focus rings (Examples 11 to 14) were manufactured by varying the protrusion length (PRL) of the protrusion (PRP) of the first ring (RIN1). The first ring (RIN1) was made of silicon carbide (SiC), and the second ring (RIN2) was made of silicon (Si). The manufactured focus rings were exposed to a plasma environment in a plasma device for 10 hours. For the focus rings exposed to the plasma environment, the degree of misalignment (i.e., offset value) of the first ring (RIN1) from the second ring (RIN2) was measured and shown in Table 2 below.

division Length of protrusion (PRP) (PRL) Plasma environment exposure time Offset values before and after plasma exposure Example 11 0.3mm 10h 0.03 mm Example 12 0.4mm 10h 0.02mm Example 13 0.5mm 10h 0.00mm Example 14 0.6mm 10h 0.00mm

Referring to Table 2, it can be seen that when the protrusion length (PRL) of the protrusion (PRP) is less than 0.5 mm, the first ring (RIN1) is slightly separated from the second ring (RIN2) in a plasma environment (Example 11 and 12). However, when the protrusion length (PRL) of the protrusion (PRP) is more than 0.5 mm, it can be confirmed that the first ring (RIN1) does not deviate from the second ring (RIN2) and maintains accurate alignment under a plasma environment (Example 13 and 14). When manufacturing a focus ring by joining the first ring and the second ring made of different materials upward and downward, the first ring and the second ring may be misaligned with each other due to a long-time etching process under the plasma environment in the plasma device. Problems with separation (separation) may occur. In order to overcome these process defects, there is an issue of manufacturing the focus ring by adopting a solid coupling structure of the first ring and the second ring.

Meanwhile, the focus ring (FCR) according to embodiments of the present invention may utilize a concave-convex coupling between the protrusion (PRP) of the first ring (RIN1) and the recessed region (RS) of the second ring (RIN2). This uneven coupling can effectively prevent defects in which the first ring and the second ring separate from each other in a plasma environment. In particular, according to embodiments of the present invention, when the protrusion length (PRL) of the protrusion (PRP) of the first ring (RIN1) is 0.5 mm or more, more specifically 0.5 mm to 1.5 mm, the etching process using plasma is performed for a long time. Even if exposed, a defect in which the first ring (RIN1) and the second ring (RIN2) are separated from each other may not occur.

Figures 5, 6, and 7 are cross-sectional views showing a focus ring according to another embodiment of the present invention. In the present embodiments, 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. 5 , the second ring RIN2 may include a plurality of recess areas, for example, a first recess area RS1 and a second recess area RS2. Each of the first and second recess regions RS1 and RS2 may have a trench shape sunken downward from the top surface of the second ring RIN2.

The first ring RIN1 may include a plurality of protrusions, for example, a first protrusion PRP1 and a second protrusion PRP2. Each of the first and second protrusions PRP1 and PRP2 protrudes downward from the bottom surface of the first ring RIN1 and may be inserted into the first and second recess regions RS1 and RS2, respectively.

A first adhesive layer (ADL1) may be provided between the first protrusion (PRP1) and the first recess area (RS1), and a second adhesive layer (ADL1) may be provided between the second protrusion (PRP2) and the second recess area (RS2). ADL2) may be provided. The first protrusion (PRP1) and the first recess region (RS1) may be adhered to each other through the first adhesive layer (ADL1), and the second protrusion (PRP2) and the second recess region may be bonded to each other through the second adhesive layer (ADL2). (RS2) can be glued together.

The first ring RIN1 may further include a plurality of recess areas, for example, a third recess area RS3 and a fourth recess area RS4. Each of the third and fourth recess regions RS1 and RS2 may have a trench shape sunken upward from the bottom surface of the first ring RIN1.

The second ring RIN2 may further include a plurality of protrusions, for example, a third protrusion PRP3 and a fourth protrusion PRP4. Each of the third and fourth protrusions PRP3 and PRP4 protrudes upward from the upper surface of the second ring RIN2 and may be inserted into the third and fourth recess regions RS3 and RS4, respectively.

A third adhesive layer (ADL3) may be provided between the third protrusion (PRP3) and the third recess area (RS3), and a fourth adhesive layer (ADL3) may be provided between the fourth protrusion (PRP4) and the fourth recess area (RS4). ADL4) can be provided. The third protrusion (PRP3) and the third recess region (RS3) can be bonded to each other through the third adhesive layer (ADL3), and the fourth protrusion (PRP4) and the fourth recess region (RS3) can be bonded to each other through the fourth adhesive layer (ADL4). (RS4) can be glued together.

The first adhesive layer (ADL1) and the second adhesive layer (ADL2) may be provided in a form embedded in the second ring (RIN2), and the third adhesive layer (ADL3) and the fourth adhesive layer (ADL4) may be provided in the first ring (RIN1). It can be provided in a form embedded within. In other words, the level at which the first and second adhesive layers ADL1 and ADL2 are located may be lower than the level at which the third and fourth adhesive layers ADL3 and ADL4 are located.

Although not shown, the first to fourth recess regions RS1 to RS4 may have different widths and different depths. Accordingly, the first to fourth protrusions PRP1 to PRP4 respectively corresponding to the first to fourth recess regions RS1 to RS4 may also have different widths and different protrusion lengths.

The focus ring FCR according to this embodiment may include not one but a plurality of uneven structures between the protrusion RPR and the recess region RS described above in FIG. 3 . Additionally, by forming the concavo-convex structures at different levels, adhesive layers can be located at different levels. As the focus ring (FCR) includes a plurality of concavo-convex structures, the mechanical stability of the focus ring (FCR) can be improved. Since the adhesive layers (ADL1-ADL4) are embedded in various positions within the focus ring (FCR), the adhesion between the first ring (RIN1) and the second ring (RIN2) can be improved.

Referring to FIG. 6 , the second ring RIN2 may include a plurality of recess areas, for example, a first recess area RS1 and a second recess area RS2. The second recess areas RS2 may be provided on both sides of the first recess area RS1, respectively.

In one embodiment, the depth DEP1 of the first recess area RS1 may be greater than the depth DEP2 of the second recess area RS2. The width of the first recess area RS1 may be larger than the width of the second recess area RS2.

The first ring RIN1 may include a plurality of protrusions, for example, a first protrusion PRP1 and a second protrusion PRP2. The second protrusions PRP2 may be provided on both sides of the first protrusion PRP1, respectively. The first protrusion PRP1 may be inserted into the first recess area RS1, and the second protrusions PRP2 may be inserted into the second recess areas RS2, respectively.

The adhesive layer (ADL) may be provided only between the first protrusion (PRP1) and the first recess region (RS1). The adhesive layer ADL may be omitted between the second protrusions PRP2 and the second recess regions RS2.

The focus ring FCR according to this embodiment may include not one but a plurality of uneven structures between the protrusion RPR and the recess region RS described above in FIG. 3 . That is, as the focus ring (FCR) includes a plurality of concavo-convex structures, the mechanical stability of the focus ring (FCR) can be improved. For some of the uneven structures, the adhesive layer can be omitted while reducing the size. For example, since the second recess region RS2 has a relatively small depth DEP2, an overflow problem may occur when an adhesive layer is provided. Accordingly, the adhesive layer is omitted in the second recess region RS2 to form a concavo-convex structure, but overflow process defects can be prevented.

Referring to FIG. 7, contrary to the focus ring (FCR) of FIG. 4, a recess area (RS) is provided at the lower part of the first ring (RIN1), and a protrusion (PRP) is provided at the upper part of the second ring (RIN2). can be provided. The recess region (RS) of the first ring (RIN1) and the protrusion (PRP) of the second ring (RIN2) may be unevenly coupled to each other.

More specifically, the second ring (RIN2) may include a body portion (BDP) and a protruding portion (PRP) protruding upward from the body portion (BDP). The protrusion PRP may extend from the upper surface of the body BDP to the inside of the recess region RS in the second direction D2. In other words, the protrusion PRP may be inserted into the recess region RS. The top surface of the protrusion (PRP) may be higher than the top surface of the body part (BDP).

In this embodiment, the width and protrusion length of the protrusion (PRP) of the second ring (RIN2) are the width (WID1) and protrusion length (PRL) of the protrusion (PRP) of the first ring (RIN1) described above with reference to FIG. 5. ) may be substantially the same as.

The adhesive layer (ADL) may be interposed between the protrusion (PRP) of the second ring (RIN2) and the recess region (RS) of the first ring (RIN1). More specifically, the adhesive layer (ADL) may be interposed between the top surface of the protrusion (PRP) and the recess region (RS).

Above, embodiments of the present invention have been described with reference to the attached drawings, but those skilled in the art will understand that the present invention can be implemented in other specific forms without changing its technical idea or essential features. You will understand that it exists. Therefore, the embodiments described above should be understood in all respects as illustrative and not restrictive.

Claims (18)

A first ring made of silicon carbide (SiC);
a second ring made of silicon (Si); and
Comprising a first adhesive layer between the first ring and the second ring,
The first ring is provided on the second ring and coupled to the second ring,
The second ring includes a first recess area recessed downward from its upper surface,
The first ring includes a first protrusion protruding downward from its bottom surface,
The first protrusion is inserted into the first recess area,
The first adhesive layer is interposed between the bottom surface of the first protrusion and the bottom of the first recess area,
The depth of the first recess area is 0.5 mm to 2 mm,
The protrusion length of the first protrusion is 0.5 mm to 1.5 mm,
A ratio of the width of the first protrusion to the maximum width of the second ring is 0.35 to 0.53.
According to paragraph 1,
The first recess area has a depth such that the adhesive layer does not overflow.
delete delete delete According to paragraph 1,
The second ring includes a portion that protrudes more outward than the first ring,
The protruding portion includes at least one mounting surface on which a shield ring can be provided.
According to paragraph 1,
The upper surface of the first ring includes a support surface for supporting a substrate, a top surface higher than the support surface, and an inclined surface connecting the support surface and the top surface.
According to paragraph 1,
The second ring further includes a second recess area recessed downward from its upper surface,
The first ring further includes a second protrusion protruding downward from its bottom surface,
The second protrusion is a focus ring inserted into the second recess area.
According to clause 8,
A focus ring wherein the depth of the first recess area is greater than the depth of the second recess area.
According to clause 9,
A focus ring wherein the bottom surface of the second protrusion directly contacts the bottom of the second recess area.
According to paragraph 1,
The first ring further includes a second recess area recessed upward from its bottom surface,
The second ring further includes a second protrusion protruding upward from its upper surface,
The second protrusion is a focus ring inserted into the second recess area.
According to clause 11,
Further comprising a second adhesive layer interposed between the second protrusion and the second recess area,
A focus ring wherein the second adhesive layer is located at a higher level than the first adhesive layer.
According to paragraph 1,
The bottom surface of the first ring and the first and second upper surfaces of the second ring contact each other,
The first recess area is located between the first upper surface and the second upper surface,
A focus ring wherein a level of a boundary where the bottom surface of the first ring and the first upper surface contact each other is the same as a level of a boundary where the bottom surface of the first ring contacts the second upper surface.
a support plate on which the substrate can be placed; and
Including an edge ring provided to surround an edge of the support plate,
The edge ring includes a focus ring and a shielding ring provided outside the focus ring,
The focus ring:
A first ring made of silicon carbide (SiC);
a second ring made of silicon (Si); and
Comprising an adhesive layer between the first ring and the second ring,
The first ring is provided on the second ring and coupled to the second ring,
The second ring includes a first recess area recessed downward from its upper surface,
The first ring includes a first protrusion protruding downward from its bottom surface,
The first protrusion is inserted into the first recess area,
The adhesive layer is interposed between the bottom surface of the first protrusion and the bottom of the first recess area,
The depth of the first recess area is 0.5 mm to 2 mm,
The protrusion length of the first protrusion is 0.5 mm to 1.5 mm,
The ratio of the width of the first protrusion to the maximum width of the second ring is 0.35 to 0.53.
According to clause 14,
The second ring includes a portion that protrudes more outward than the first ring,
The protruding portion includes at least one mounting surface,
A plasma device wherein the shielding ring is provided on the mounting surface.
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