EDGE COVERING AND SEMICONDUCTOR MANUFACTURING DEVICE COMPRISING THE SAME

There is provided an edge covering having a structure capable of effectively removing polymer. The edge covering includes a lower ring including a first hole, and an upper ring which is installed on the lower ring and includes a second hole that overlaps the first hole, wherein an edge ring is seated on an upper surface of the lower ring, and the upper ring includes a first side wall that faces the second hole and forms a first angle with the upper surface of the lower ring, the first angle being an acute angle.

This application claims priority from Korean Patent Application No. 10-2023-0020753 filed on Feb. 16, 2023, and Korean Patent Application No. 10-2023-0026990 filed on Feb. 28, 2023, in the Korean Intellectual Property Office, and all the benefits accruing therefrom under 35 U.S.C. 119, the contents of which in their entirety are herein incorporated by reference.

BACKGROUND

1. Field of the Invention

The present disclosure relates to an edge covering and a semiconductor manufacturing device including the same.

2. Description of the Related Art

As semiconductors become more precise, an improved process of etching a wafer is required. Foreign matter adhering to the wafer during the etching process may cause deterioration of performance.

In particular, a polymer, which may be a by-product of etching the wafer, may be deposited. Unremoved polymer can fall back onto the wafer and impede etching. this may cause defects. As a result, polymer that is not removed during the process of etching the wafer may cause problems in quality of the semiconductor.

SUMMARY

Aspects of the present disclosure provide an edge covering having a structure capable of effectively removing polymer.

Aspects of the present disclosure also provide a semiconductor manufacturing device including the edge covering having the structure capable of effectively removing polymers.

According to an aspect of the present disclosure, there is provided an edge covering comprising a lower ring including a first hole, and an upper ring on the lower ring, where the upper ring includes a second hole that overlaps the first hole, wherein an edge ring is seated on an upper surface of the lower ring, and the upper ring includes a first side wall that faces the second hole and forms a first angle with the upper surface of the lower ring, the first angle being an acute angle.

According to another aspect of the present disclosure, there is provided an edge covering comprising a lower ring which includes a first hole having a lower ring inner diameter, and an upper ring which includes a second hole having an upper ring inner diameter, wherein an edge ring is seated on an upper surface of the lower ring, and the upper ring includes a first side wall that faces the second hole and increases in thickness from an inner side to an outer side of the upper ring.

According to still another aspect of the present disclosure, there is provided a semiconductor manufacturing device comprising an edge covering, an edge ring that is seated on an inner side of the edge covering, an electrostatic chuck which faces the inner side of the edge covering and on which a substrate is loadable, and an upper electrode and a lower electrode spaced apart from each other with an electrostatic chuck interposed therebetween, wherein the edge covering includes a lower ring including a first hole, and an upper ring which is installed on the lower ring and includes a second hole that overlaps the first hole, wherein the edge ring is seated on an upper surface of the lower ring, and the upper ring includes a first side wall that faces the second hole and forms a first angle with the upper surface of the lower ring, the first angle being an acute angle.

DETAILED DESCRIPTION OF THE EMBODIMENTS

Embodiments of the present disclosure will be described in detail below with reference to the accompanying drawings. The same reference numerals are used for the same components on the drawings, and repeated descriptions thereof will not be provided.

FIG.1is a cross-sectional view of a semiconductor manufacturing device according to some embodiments of the present disclosure.

Referring toFIG.1, a semiconductor manufacturing device may be provided. In this specification, the semiconductor manufacturing device may be a device that performs a process of etching a material such as a wafer W. More specifically, the semiconductor manufacturing device may be a CCP (Capacitively Coupled Plasma) device that performs a dry etching. The CCP device relates to a device that generates plasma after forming an electric field by applying Radio Frequency (RF) power between parallel electrodes facing each other. However, the present disclosure is not limited thereto, and may be a device such as an ICP (Inductively Coupled Plasma) that performs the dry etching. The ICP has an external coil outside the chamber, forms a magnetic field using an applied electric field, and generates a plasma by an electric field induced to the magnetic field.

The semiconductor manufacturing device includes a housing H, a gas injection port I, a gas distribution port D, an upper electrode UE, a lower electrode LE, an electrostatic chuck C, an edge ring200, an edge covering100, a ground ring401, a coupler403, a ground electrode402, a generator G, a movement control unit301, a confinement ring302, and a ring connection unit303.

The housing H may define a chamber inner space CS, where the atmosphere within the chamber inner space CS may be controlled. More specifically, the housing H may define an empty inner space that allows the constituent elements of the semiconductor manufacturing device to be disposed. For example, the upper electrode UE, the lower electrode LE, the electrostatic chuck C, the edge ring200, the edge covering100, the ground ring401, the coupler403, the ground electrode402, the generator G, and other components of the semiconductor manufacturing device may be disposed in the chamber inner space CS.

The gas injection port I is a structure into which an etching gas used in an etching process is injected. For example, the gas injection port I has a hollow columnar shape, and may inject an etchant from the outside of the housing H into the plasma injection space IS.

The etchant may have a suitable gas combination ratio depending on the material to be etched. For example, when the material to be etched is silicon (Si), an appropriate combination of NF3, SF6, CF4, may be used as the etchant.

In various embodiments, the semiconductor manufacturing device may further include a mass flow controller (MFC). An amount of etchant injected through the gas injection port I may be controlled through a mass flow meter. In the case of gas, considering that each gas can have a different mass and a unit volume of same kind of gas may also change depending on a temperature and a pressure, the mass flow meter may control the mass of the etchant that is injected through the gas injection port I.

The gas distribution ports D may allow passage of the etchant used in the etching process into a plasma formation space FS from a plasma injection space IS. For example, the gas distribution ports D may have a hollow columnar shape, and may allow the etchant injected through the gas injection port I to pass into the plasma formation space FS. The gas distribution ports D may collectively be referred to as a shower head.

The plurality of gas distribution ports may have a structure that penetrates the upper electrode UE. For example, the plurality of gas distribution ports may be passages that connect the plasma injection space IS and the plasma formation space FS.

The upper electrode UE is an electrode for generating plasma together with the lower electrode LE, where the upper electrode UE may be a cathode. The upper electrode UE may be made of, but is not limited to, silicon. The upper electrode UE may be spaced apart from the upper surface of the electrostatic chuck C.

The lower electrode LE is an electrode for generating plasma together with the upper electrode UE, where the lower electrode LE may be an anode. The lower electrode LE may be made of, but is not limited to, silicon. The upper surface of the lower electrode LE may be in contact with the lower surface of the electrostatic chuck C.

The electrostatic chuck C can apply high frequency power to chuck a wafer W during an etching process, and the high frequency power can be removed from the electrostatic chuck C to dechuck the wafer W after the etching process is completed. In addition, the electrostatic chuck C may allow flow of coolant to prevent the temperature of the wafer W from rising due to heat generated during the etching process. Therefore, the temperature of the wafer W may be controlled through the electrostatic chuck C.

In various embodiments, a minute space may exist between the wafer W and the electrostatic chuck C. A gas having excellent thermal conductivity may flow in the space between the wafer W and the electrostatic chuck C, so that the electrostatic chuck C may more effectively control the temperature of the wafer W. For example, the temperature of the wafer W may be effectively lowered by causing a He gas, which has excellent thermal conductivity, to flow between the electrostatic chuck C and the wafer W.

The edge ring200may be in the form of a ring and may be formed to surround the periphery of the electrostatic chuck C. The plasma formed in the plasma formation space FS may be concentrated on the upper surface of the wafer W by the edge ring200, where the plasma may be formed uniformly. The ring shape may be a shape with a circular opening at the center.

In various embodiments, the ring-shaped edge ring200may concentrate the plasma generated for the etching process on the wafer W. The edge ring200may be made of silicon (Si). Because the main constituent of the wafer W may also be silicon, the plasma may be concentrated on the wafer W when the edge ring200is made of silicon (Si). More specifically, the material of the wafer W and the material of the edge ring200can be made of the same material, so that the plasma may uniformly etch the wafer W.

The edge ring200may be separated into a first edge ring member201and a second edge ring member202, where the first edge ring member201may be above the second edge ring member202. An upper side is called the first edge ring member201and a lower side is called the second edge ring member202on the basis of a plane passing through a first direction X and a second direction Y intersecting the first direction. For convenience of explanation, althoughFIG.1shows a case where the plane passing through the first direction and the second direction is the same plane as a lower surface of the edge covering100, the present disclosure is not limited thereto. The first edge ring member201may have a different cross-sectional shape than the second edge ring member202, where the second edge ring member202may have a rectangular cross-section.

The plasma can etch the wafer W, but may also unintentionally etch some peripheral constituent elements. For example, the plasma may etch the upper surface of the edge ring200where the first edge ring member201may be exposed. When etching the upper surface of the edge ring200, the upper surface of the edge ring200may change unevenly. As a result, the edge ring200may not play the role of uniformly forming the plasma, where the uneven surface may affect the electric and/or magnetic fields. Maintaining the upper surface of the edge ring200uniform in the etching process may maintain a uniform plasma.

Because etching of the edge ring200is concentrated on the upper surface of the edge ring200, the first edge ring member201forming the upper surface of the edge ring200may be replaced to keep the upper surface of the edge ring200uniform in the etching process. Since the first edge ring member201may be independently replaced to keep the upper surface of the edge ring200uniform without replacing the second edge ring member202or the entire edge ring200(the first edge ring member201and the second edge ring member202), replacement costs may be reduced. Therefore, separation of the edge ring200into the first edge ring member201and the second edge ring member202may provide an approach for reducing the replacement costs.

Referring toFIG.1, the lower surface of the first edge ring member201and the upper surface of the second edge ring member202can be in physical contact with each other. However, when the first edge ring member201is lifted in a third direction Z intersecting the first direction and the second direction after being gripped, the first edge ring member201can be detached from the upper surface of the second edge ring member202. Therefore, after etching is performed and the first edge ring member201having an uneven upper surface is detached, a new first edge ring member201having a uniform upper surface may be put on the upper surface of the second edge ring member202to replace the first edge ring member201. The lower surface of the first edge ring member201can be coextensive with the upper surface of the second edge ring member202in the X direction.

The edge covering100may be in the form of a ring, and may be formed to surround the periphery of the edge ring200. The second edge ring member202may be seated in a recess in the edge covering100.

The edge covering100can be between the edge ring200and the ground ring401and may electrically insulate the edge ring200from the ground ring401. A coupler403may be between the first edge ring member201and the ground ring401. The edge covering100may be made up of quartz.

There is a heat conduction difference between the edge ring200and the edge covering100. More specifically, the temperature of edge ring200may be relatively higher than the temperature of the edge covering100. Polymer (P), which is a by-product generated during the etching process, has features in which it is not deposited at a high temperature but is easily deposited at a low temperature. Therefore, a large amount of polymer (P) may be deposited on an interface between the edge ring200and the edge covering100.

If a large amount of polymer (P) is deposited, the polymer (P) may fall on the wafer W side during the etching process. The polymer (P) which falls on the wafer W side plays a role of impeding etching, and therefore may cause a short circuit or a disconnection. As a result, the performance of the semiconductor may be degraded. A detailed description of the structure of the edge ring200for preventing this will be provided below inFIG.2.

The ground ring401may be in the form of a ring and may be formed to surround the periphery of the edge covering100. The ground ring401may be electrically conducting and ground the supplied power. The ground ring401may be made up of aluminum (Al).

Although it is not shown, the ground ring401may be electrically connected to the upper electrode UE or the electrostatic chuck C. However, the embodiment is not limited thereto. The ground ring401may be electrically connected to the upper electrode UE or the electrostatic chuck C via other configurations. In addition, the ground ring can constitute a closed circuit to allow current to flow to the outside of the apparatus, where the ground ring may be connected to other components of the semiconductor manufacturing device.

A coupler403may couple a DC voltage generated between the bulk plasma and the electrostatic chuck C. An upper surface of the coupler403may be connected to the lower surface of the edge covering100. More specifically, the output impedance of the generator G and the chamber impedance may be matched to control the coupling voltage between the bulk plasma and the electrostatic chuck C to be large.

The ground electrode402may ground the upper electrode UE or the electrostatic chuck C. The upper surface of the ground electrode402may be connected to the lower surface of the ground ring401. The ground electrode402may be grounded on the outside to ground the upper electrode UE or the electrostatic chuck C.

The generator G may supply a high frequency power for plasma generation. For the power supply, the generator G may be connected with the electrostatic chuck C through a fin. The generator G may be in the form of surrounding the fin.

The movement control unit301is located on the upper surface of the ring connection unit303and may be connected to a confinement ring302, where the ring connection unit303can be between the movement control unit301and the confinement ring302. The movement control unit301may include a motor. The height of the confinement ring302may be adjusted when the motor rotates, and the plasma formation space FS may be sealed through the movement control unit301.

The confinement ring302may be in the form of a ring. The confinement ring302may surround the upper electrode UE and/or surround the plasma formation space FS. An inner diameter of the confinement ring can be sufficiently large to fit around the upper electrode UE, and at least a portion of the confinement ring302may be in close contact with an outer side of the upper electrode UE. A plurality of confinement rings302may be arranged along the third direction, where the confinement rings302can be stacked and adjacent confinement rings302can be connected to each other through the ring connection unit303. Therefore, the plasma formation space FS may be sealed when the space between the plurality of confinement rings302decreases.

When sealing the plasma formation space FS, the motor of the movement control unit301rotates in the first direction (for example, a clockwise direction). All the confinement rings may gradually descend downward by the action of the motor of the movement control unit301. Because the adjacent confinement rings are connected through the ring connection unit303, the movement due to the motor of the movement control unit301may be transferred to all the confinement rings, where the confinement rings302may descend towards he ground ring401. A portion of the lowermost confinement ring302may come into contact with an upper surface of the ground ring401. After the lowermost confinement ring302comes into contact with the ground ring401, further descent may be blocked by the ground ring401. Therefore, the confinement ring may not descend any lower. Because the ring connection unit303may be a film-like structure that may be expanded and contracted in the third direction, when the confinement ring302descends, the ring connection unit303can expand simultaneously, while being connected to the adjacent confinement ring. Eventually, the plurality of confinement rings302and the ring connection unit303may seal the plasma formation space FS.

When the plasma formation space FS is opened, the motor of the movement control unit301rotates in the second direction (for example, a counterclockwise direction). All the confinement rings302may gradually ascend upward by the motor of the movement control unit301. Since the adjacent confinement rings302are connected through the ring connection unit303, the movement due to the motor of the movement control unit301may be transferred to all the confinement rings302. In this case, the lowermost confinement ring ascends and may be spaced apart from the ground ring401. Since the ring connection unit303may be a film-like structure that may be expanded and contracted in the third direction, when the confinement ring302ascends, the ring connection unit303simultaneously contracts, while being connected to the adjacent confinement ring. Eventually, the plurality of confinement rings and the ring connection unit303may open the plasma formation space FS. The plasma formation space FS may be fluidly connected passed the confinement ring302and ring connection unit303to the chamber inner space CS.

In various embodiments, the semiconductor manufacturing device may further include a vacuum pump. The vacuum pump may include a dry pump which may draw gas from an atmospheric pressure to a low vacuum level and a turbo pump which may draw gas to a high vacuum level.

The vacuum pump can be used to draw the gas out of the chamber, but polymer (P), which is by-product, may also partially move in a direction in which the gas is drawn. That is, the polymers (P) existing in the plasma formation space FS may move to the chamber inner space CS.

FIG.2is an enlarged view of a portion R1ofFIG.1.

Referring toFIG.2, the edge ring200may be separated into a first edge ring member201and a second edge ring member202. Also, the first edge ring member201may be separated into a ring-shaped upper first edge ring201U and a ring-shaped lower first edge ring201L. However, for convenience of explanation, the first edge ring member201is separated into the upper first edge ring201U and the lower first edge ring201L, and the first edge ring member201may be a structure in which the upper first edge ring201U and the lower first edge ring201L are two sections of a single structure formed integrally.

The upper first edge ring201U may include a first edge ring protrusion204, a first edge ring side wall205, a first edge ring extension surface206, and a second edge ring extension surface207.

The edge ring protrusion204may exist outside the upper first edge ring201U. Although the edge ring protrusion204is shown as being vertically contiguous with the upper surface of the lower first edge ring201L for convenience of explanation, the embodiment is not limited thereto. Since the edge ring protrusion204exists at the outermost part of the first edge ring member201, the edge ring protrusion204may have a protruding shape when viewed from the outside.

The first edge ring extension surface206connects the uppermost end of the edge ring side wall205and the uppermost end of the edge ring protrusion204. Although the first edge ring extension surface206is shown as being parallel to the upper surface of the lower first edge ring201L for convenience of explanation, the embodiment is not limited thereto.

The second edge ring extension surface207connects an uppermost end of an edge ring recess surface203, which will be described below, with the lowermost end of the edge ring protrusion204. Although the second edge ring extension surface207is shown as being parallel to the upper surface of the lower first edge ring201L for convenience of explanation, the embodiment is not limited thereto. Although the second edge ring extension surface207is also shown as being parallel to the first edge ring extension surface206, the embodiment is not limited thereto.

The lower first edge ring201L may include an edge ring recess surface203.

The edge ring recess surface203may be outside the lower first edge ring201L. Although the edge ring recess surface203is shown as being vertically connected to the lower surface of lower first edge ring201L for convenience of explanation, the embodiment is not limited thereto. The edge ring recess surface203forms a step between the bottom surface of the lower first edge ring201L and the second edge ring extension surface207, such that the edge ring protrusion204extends away from the lower first edge ring201L. Therefore, the edge ring recess surface203may have a recessed shape when viewed from the outside.

As a result, the edge ring recess surface203, the edge ring protrusion204, and the second edge ring extension surface207may have a stepped shape when viewed from the outside.

Referring toFIG.2again, the edge ring200may be loaded inside the edge covering100, where the edge covering100can support at least a portion of the edge ring200. A method of loading the edge ring200is as follows.

First, the first edge ring member201is gripped. The first edge ring member201may be gripped by applying a proper pressure to the first edge ring member201after any operator puts on gloves. At this time, the gloves may be made of a material that prevents foreign matters from being adsorbed to the first edge ring member201.

Next, the first edge ring member201is put on the upper surface of the second edge ring member202to be sandwiched between the inner side of the edge covering100and the electrostatic chuck C.

As will be described below, the edge covering100has a first loading portion110. When the first edge ring member201is put on the upper surface of the second edge ring member202and the first loading portion110, the first loading portion110and the second edge ring extension surface207may be in physical contact with each other.

The inner side of the lower ring102and the edge ring recess surface203may not be separated from each other. Therefore, the generated polymer (P) may not penetrate between the inner side of the lower ring102and the edge ring recess surface203. Also, the first loading portion110and the second edge ring extension surface207that are in contact with each other may not be separated from each other. Therefore, the generated polymer (P) may not penetrate between the first loading portion110and the second edge ring extension surface207.

Referring toFIG.2again, a ground ring401may be loaded on the outer side of the edge covering100. As will be described below, the edge covering100has a second loading portion120. When the ground ring401is put on the upper surface of the ground electrode402and the second loading portion120, the second loading portion120and at least a part of the lower surface of the ground ring401may be in contact with each other. Also, the ground ring protrusion404may be in contact with the second side wall SW2.

FIG.3is a perspective view of the edge covering100according to some embodiments of the disclosure.FIG.4is a cross-sectional view taken along a line A-A ofFIG.3.

Referring toFIGS.3and4, the edge covering100may be separated into an upper ring101and a lower ring102. However, the edge covering100is separated into the upper ring101and the lower ring102for convenience of explanation, and the edge covering100may be a structure in which the upper ring101and the lower ring102are integrally formed.

The lower ring102is in the form of a ring and may include a first hole LH. For example, the first hole LH is an empty space, and may have a structure through which a cylinder having the center of the lower ring102as a central axis CP penetrates. In this case, an outer diameter of the cylinder of the first hole LH may be an inner diameter L2of the lower ring.

Since the lower ring102is in the form of a ring, the outermost contour of the lower surface of the lower ring102may form a circle when the lower ring102is flattened in the third direction. In this case, the diameter of the circle may be an outer diameter L1of the lower ring.

The upper ring101is in the form of a ring and may include a second hole UH. For example, the second hole UH is an empty space, and may have a structure through which a truncated cone having the center of the upper ring101as a central axis CP penetrates. In this case, among the circles of truncated cone of the second hole UH, there may be a circle positioned on the upper surface side of the lower ring102, and the diameter of this circle may be the inner diameter U2of the upper ring.

Since the upper ring101is in the form of a ring, when the upper ring101is flattened in the third direction, the outermost contour of the upper surface of the upper ring101may form a circle. In this case, the diameter of the circle may be the outer diameter U1of the upper ring.

The first hole LH may overlap the second hole UH. More specifically, the upper surface of the first hole LH may face the lower surface of the second hole UH. The first hole LH and the second hole UH may be centered on the same axis.

The upper ring101includes a first side wall SW1, a second side wall SW2, and a first extension surface171extending from the first side wall SW1to the second side wall SW2.

The first side wall SW1may form a first angle a1with the upper surface of the lower ring102, and the first angle a1may be an acute angle. That is, the thickness h1of the first side wall SW1may increase from the inner side to the outer side of the upper ring101.

InFIG.4, the first side wall SW1is shown to linearly increase in thickness from the inner side to the outer side of the upper ring101. That is, the extent to which the thickness h1of the first side wall SW1increases from the inner side to the outer side of the upper ring101is constant, and the first side wall SW1is shown in the form of a straight line. However, the thickness h1of the first side wall SW1may increase nonlinearly from the inner side to the outer side of the upper ring101without being limited thereto.

The second side wall SW2may form a second angle a2with the upper surface of the lower ring102. When the second angle a2is 90 degrees, the second side wall SW2may form a right angle with the upper surface of the lower ring102. The thickness h2of the second side wall SW2may be constant. Although not illustrated inFIG.4, the thickness h2of the second side wall SW2may increase from the outer side toward the inner side of the upper ring101when the second angle a2is an acute angle other than 90 degrees.

In other words, the second side wall SW2is shown to form a right angle with the upper surface of the lower ring102as shown inFIG.4. However, the thickness h2of the second side wall SW2may increase from the outer side to the inner side of the upper ring101without being limited thereto.

The second angle a2may be greater than the first angle a1. For example, since the second angle a2is a right angle, it may be greater than the first angle a1which is an acute angle.

The first extension surface171may connect the uppermost end of the first side wall SW1and the uppermost end of the second side wall SW2. For example, the first extension surface171comes into contact with the uppermost end of the first side wall SW1and the uppermost end of the second side wall SW2and connect them to each other, and may be parallel to the upper surface of the lower ring102.

The lower ring102includes a first loading portion110and a second loading portion120.

The first loading portion110may be a part of the upper surface of the lower ring102. More specifically, the first loading portion110may be a portion that connects the upper end of the inner side wall of the lower ring102and the lower end of the first side wall SW1, and exists inside the upper surface of the lower ring102.

The second loading portion120may be a part of the upper surface of the lower ring102. More specifically, the second loading portion120may be a portion that connects the upper end of the outer side wall of the lower ring102and the lower end of the second side wall SW2, and exists outside the upper surface of the lower ring102.

An edge ring200may be seated on the upper surface of the lower ring102. For example, the edge ring200is seated on the first loading portion110, and the second edge ring extension surface207and the first loading portion110may be in contact with each other.

The thickness may mean a thickness in the third direction Z herein. For example, inFIG.4, the thickness of the first side wall SW1may refer to a vertical distance from the upper end at an arbitrary point of the first side wall SW1to the upper surface of the lower ring102.

In this specification, the inner side may refer to a portion in which a straight distance is closer from the ring-shaped central axis CP, and the outer side may refer to a portion in which the straight distance is farther from the ring-shaped central axis CP. For example, the inner side of the lower ring102ofFIG.4may be a portion having the lower ring inner diameter L2. Also, the outer side of the lower ring102ofFIG.4may be a portion having the lower ring outer diameter L1.

FIG.5is a cross-sectional view of the edge covering100according to some embodiments of the present disclosure. For convenience of explanation, points different from those explained usingFIGS.3and4will be mainly explained.

Referring toFIG.5, the edge covering100may be separated into the upper ring101and the lower ring102. However, the edge covering100is separated into the upper ring101and the lower ring102for convenience of explanation, and the edge covering100may be a structure in which the upper ring101and the lower ring102are integrally formed.

The third side wall SW3may form a third angle a3with the upper surface of the lower ring102, and the third angle a3may be an acute angle. That is, the thickness h3of the third side wall SW3may increase from the inner side to the outer side of the upper ring101.

InFIG.5, the third side wall SW3is shown to linearly increase in thickness from the inner side to the outer side of upper ring101. That is, the extent to which the thickness h3of the third side wall SW3increases from the inner side to the outer side of the upper ring101is constant, and the third side wall SW3is shown linearly. However, the thickness h3of the third side wall SW3may increase nonlinearly from the inner side to the outer side of the upper ring101, without being limited thereto.

The fourth side wall SW4may form a fourth angle a4with the upper surface of the lower ring102. When the fourth angle a4is 90 degrees, the fourth side wall SW4may form a right angle with the upper surface of the lower ring102. The thickness h4of the fourth side wall SW4may be constant. Although not illustrated inFIG.5, the thickness h4of the fourth side wall SW4may increase from the outer side to the inner side of the upper ring101when the fourth angle a4is an acute angle other than 90 degrees.

In other words, the fourth side wall SW4is shown to form a right angle with the upper surface of the lower ring102as shown inFIG.5. However, the thickness h4of the fourth side wall SW4may increase from the outer side to the inner side of the upper ring101, without being limited thereto.

The fourth angle a4may be greater than the third angle a3. For example, since the fourth angle a4is a right angle, it may be greater than the third angle a3which is an acute angle.

The second extension172may connect the uppermost end of the third side wall SW3and the uppermost end of the fourth side wall SW4. For example, the second extension172comes into contact with the uppermost end of the third side wall SW3and the uppermost end of the fourth side wall SW4and connects them to each other, but may not be parallel to the upper surface of the lower ring102.

The second extension172may form a fifth angle a5with the upper surface of the lower ring102. That is, the thickness h5of the second extension172may increase from the inner side to the outer side of the upper ring101.

InFIG.5the second extension172is shown to linearly increase in thickness from the inner side to the outer side of the upper ring101. That is, the extent to which the thickness h5of the second extension172increases from the inner side to the outer side of the upper ring101is constant, and the second extension172is shown linearly. However, the thickness h5of the second extension172may increase nonlinearly from the inner side to the outer side of the upper ring101, without being limited thereto.

The fifth angle a5may be smaller than the fourth angle a4and may be an acute angle. That is, the thickness h5of the second extension172may increase from the inner side to the outer side of the upper ring101.

The lower ring102may include a third loading portion130and a fourth loading portion140. The third loading portion130may correspond to the first loading portion110ofFIGS.3and4. The fourth loading portion140may correspond to the second loading portion120ofFIGS.3and4.

FIG.6is a cross-sectional view of the edge covering100according to some embodiments of the present disclosure. For convenience of explanation, points different from those explained usingFIGS.3and4will be mainly explained.

Referring toFIG.6, the edge covering100may be separated into the upper ring101and the lower ring102. However, the edge covering100is separated into the upper ring101and the lower ring102for convenience of explanation, and the edge covering100may be a structure in which the upper ring101and the lower ring are integrally formed.

The fifth side wall SW5may form a sixth angle a6with the upper surface of the lower ring102, and the sixth angle a6may be an acute angle. That is, the thickness h6of the fifth side wall SW5may increase from the inner side to the outer side of the upper ring101.

InFIG.6, the thickness h6of the fifth side wall SW5is shown to linearly increase from the inner side to the outer side of the upper ring101. That is, the extent to which the thickness h6of the fifth side wall SW5increases from the inner side to the outer side of the upper ring101is constant, and the fifth side wall SW5is shown linearly. However, the thickness h6of the fifth side wall SW5may increase nonlinearly from the inner side to the outer side of the upper ring101, without being limited thereto.

The sixth side wall SW6may form a seventh angle a7with the upper surface of the lower ring102. When the seventh angle a7is 90 degrees, the sixth side wall SW6may form a right angle with the upper surface of the lower ring102. The thickness h7of the sixth side wall SW6may be constant. Although no illustrated inFIG.6, the thickness h7of the sixth side wall SW6may increase from the outer side to the inner side of the upper ring101when the seventh angle a7is an acute angle other than 90 degrees.

In other words, the sixth side wall SW6is shown to form a right angle with the upper surface of lower ring102as shown inFIG.6. However, the thickness h7of the sixth side wall SW6may increase from the outer side to the inner side of the upper ring101, without being limited thereto.

The seventh angle a7may be greater than the sixth angle a6. For example, since the seventh angle a7is a right angle, it may be greater than the sixth angle a6which is an acute angle.

The third extension173comes into the uppermost end of the fifth side wall SW5and the uppermost end of the sixth side wall SW6and connects them to each other, and may be parallel to the upper surface of the lower ring102.

The sixth side wall SW6may be the outer side wall of the edge covering100. More specifically, the outer side wall of the upper ring101may be a part of the sixth side wall SW6. Also, the outer side wall of the lower ring102may be the rest of the sixth side wall SW6. Therefore, the outer side wall of the edge covering100is the sixth side wall SW6, which may have a flat structure without tilting or bending.

The lower ring102may include a fifth loading portion150. The fifth loading portion150may correspond to the first loading portion110ofFIGS.3and4.

FIG.7is a cross-sectional view showing a semiconductor manufacturing device with a wafer seated thereon according to some embodiments of the present disclosure.FIG.8is an enlarged view of a portion R2ofFIG.7. For convenience of explanation, the points different from those explained usingFIGS.1and2will be mainly explained.

Referring toFIGS.7and8, a wafer W is chucked to the upper surface of the electrostatic chuck C and polymer (P) is accumulated during the etching process.

When a carbon (C)-based gas is used as the etching gas, the polymer (P) having a chemical formula CxFymay be generated around the wafer W. Since the ions are incident perpendicularly to the substrate during the etching process, a relatively large amount of the polymer (P) may be removed from the upper surface of the wafer W by such ions. However, since the ions are hardly incident on the side surfaces of the wafer W, polymer (P) may be accumulated.

The edge ring200that surrounds the periphery of the wafer W may be made of Si material and thus has a relatively high thermal conductivity. Therefore, because the thermal energy generated during the plasma process may be received relatively easily, a relatively high temperature may be maintained. On the other hand, the edge covering100that surrounds the edge ring200may be made of a quartz material and thus has a relatively low thermal conductivity. Therefore, because the heat energy generated during the plasma process is less likely to be transferred, a relatively low temperature may be maintained.

In the case of polymer (P), there is a feature in which it is hard to be adsorbed to substances with high temperatures, and is easily adsorbed to substances with low temperatures. Therefore, although the polymer (P) may be accumulated on the side surface of the wafer W, the polymer (P) is hard to be accumulated on the edge ring200and a large amount of the polymer (P) may be accumulated on the edge covering100.

Furthermore, a trench may occur in the space between the edge ring200and the edge covering100, which may be regarded as a boundary between the edge ring200and the edge covering100, due to the difference in level and inclination between the edge ring200and the edge covering100. More specifically, due to the difference in thickness between the edge covering100and the edge ring200and the difference in inclination between the edge ring protrusion204and the first side wall SW1, a trench may occur in the space between the edge ring200and the edge covering ring100. Therefore, when the polymer (P) enters the trench, it is not easy to exit the trench.

As a result, a large amount of polymer (P) may be accumulated in the space between the edge ring200and the edge covering100, that is, between the edge ring protrusion204and the first side wall SW1.

As explained above, the first side wall SW1may have the first angle a1with the upper surface of the lower ring102. Also, the polymer (P) may move from the plasma formation space FS to the chamber inner space CS due to the influence of the vacuum pump.

The plurality of polymers (P) may be adsorbed onto the surface of the first side wall SW1, and the polymers (P) not adsorbed onto the surface of the first side wall SW1may be accumulated on the surface of the first side wall SW1in an unfixed state. The unfixed polymers (P) may move in a direction of an arrow ofFIG.8along the inclination of the first side wall SW1having the first angle a1. In other words, the polymer (P) may move from the inner side to the outer side of the edge covering100.

Assuming that the first angle a1is an obtuse angle, the polymer (P) may move from the outer side to the inner side of the edge covering100when moving along the inclination of the first side wall SW1. Therefore, the polymer (P) is more likely to reach the wafer W, and the wafer W located inside the edge covering100may be more likely to be contaminated with the polymer (P).

In all embodiments of the present disclosure, since the first angle a1is an acute angle, the polymer (P) may move to the outer side of the edge covering100along the inclination of the first side wall SW1. Therefore, the edge covering100is less likely to reach wafer W, and the wafer W positioned inside the edge covering100may be less likely to be contaminated with polymer (P).