Electro static chuck

Abstract

An electrostatic chuck according to an embodiment of the present invention comprises an electrostatic chuck body having a step portion protruding from a lower portion, an adhesive layer disposed on the upper surface of the electrostatic chuck body, a ceramic puck disposed to be adhered to the adhesive layer and having an edge protruding from the upper surface of the electrostatic chuck body, and a sealing member disposed between the step portion and the edge of the ceramic puck to prevent the penetration of reaction gas into the adhesive layer, wherein the sealing member has a coating layer on its outer surface, and the coating layer may be composed of either a metal oxide including a single rare earth oxide or a multilayer heterogeneous metal oxide.

Description

Technology Field

[0001] The present invention relates to an electrostatic chuck. Background Technology

[0003] Semiconductor devices or display devices are manufactured by stacking and patterning multiple thin film layers, including dielectric layers and metal layers, on a glass substrate, a flexible substrate, or a semiconductor wafer substrate through semiconductor processes such as chemical vapor deposition (CVD), physical vapor deposition (PVD), ion implantation, and etching processes.

[0004] A chamber device for performing these semiconductor processes supports various substrates such as glass substrates, flexible substrates, and semiconductor wafer substrates, and is equipped with an electrostatic chuck (ESC) for fixing the substrate using electrostatic force or for plasma treatment. Additionally, the electrostatic chuck is equipped with a sealing member for protecting the adhesive layer for bonding the ceramic plate on which the substrate is placed.

[0005] However, as the process progresses, there is a problem that the sealing member must be replaced after a certain period of time due to etching of the sealing member. In addition, there is a problem that the edge temperature of the ceramic plate rises due to the sealing member being made of a material with low thermal conductivity, resulting in poor edge yield of the substrate. The problem to be solved

[0007] One of the technical problems that the technical concept of the present invention aims to solve is to provide an electrostatic chuck capable of improving process yield at the edge of a substrate by suppressing the temperature rise at the edge. means of solving the problem

[0009] An electrostatic chuck according to an exemplary embodiment comprises an electrostatic chuck body having a step portion protruding from a lower portion, an adhesive layer disposed on the upper surface of the electrostatic chuck body, a ceramic puck disposed to be adhered to the adhesive layer and having an edge protruding from the upper surface of the electrostatic chuck body, and a sealing member disposed between the step portion and the edge of the ceramic puck to prevent the penetration of reaction gas into the adhesive layer, wherein the sealing member has a coating layer on its outer surface, and the coating layer may be composed of either a metal oxide including a single rare earth oxide or a multilayer heterogeneous metal oxide. Effects of the invention

[0011] An electrostatic chuck can be provided that can improve process yield at the edge of a substrate by suppressing the temperature rise at the edge.

[0012] The various and beneficial advantages and effects of the present invention are not limited to those described above and will be more easily understood in the process of explaining specific embodiments of the present invention. Brief explanation of the drawing

[0014] FIG. 1 is a configuration diagram showing an etching apparatus equipped with an electrostatic chuck according to exemplary embodiments. FIG. 2 is a configuration diagram showing an electrostatic chuck according to an exemplary embodiment. FIG. 3 is an enlarged view showing part B of FIG. 2. FIG. 4 is a perspective view showing a sealing member provided in an electrostatic chuck according to an exemplary embodiment. FIG. 5 is a perspective view showing a sealing member provided in an electrostatic chuck according to an exemplary embodiment. FIG. 6 is a configuration diagram showing an electrostatic chuck according to an exemplary embodiment. FIG. 7 is a configuration diagram showing an electrostatic chuck according to an exemplary embodiment. FIG. 8 is a configuration diagram showing an electrostatic chuck according to an exemplary embodiment. FIG. 9 is a configuration diagram showing an electrostatic chuck according to an exemplary embodiment. Specific details for implementing the invention

[0015] Preferred embodiments of the present invention will be described below with reference to the attached drawings.

[0017] FIG. 1 is a schematic diagram showing an etching apparatus according to exemplary embodiments.

[0019] Referring to FIG. 1, an etching device (10) comprises a reaction chamber (11) into which a wafer (not shown) is loaded. The reaction chamber (11) provides a space for performing an etching process on the loaded wafer and includes a susceptor (12) having an electrostatic chuck (100) on which the wafer is placed, and an upper electrode (13) disposed on top of the susceptor (12). Each of the susceptor (12) and the upper electrode (13) has a roughly cylindrical shape, and the reaction chamber (11) can be grounded through a ground wire (21).

[0021] Meanwhile, an electrostatic chuck (100) is positioned on the upper part of the susceptor (12) to secure the wafer. The electrostatic chuck (100) comprises two polyimide-based films and a conductive film positioned between them. The conductive film is connected to a high-voltage DC power source (22) positioned outside the reaction chamber (11).

[0023] When a predetermined voltage is applied to a conductive thin film from a high-voltage DC power source (22), charges are generated on the surface of the polyimide film, and a Coulomb force is generated to fix the wafer to the upper surface of the electrostatic chuck (100). However, the method of fixing the wafer is not limited to using an electrostatic chuck, and a method of fixing the wafer using a mechanical device such as a clamp may also be used.

[0025] The upper electrode (13) is positioned on the upper part of the electrostatic chuck (100) to face the susceptor (12). The lower portion of the upper electrode (13) may be made of silicon to stabilize the atmosphere inside the reaction chamber (11) during the etching process. The silicon may be of a thickness sufficient to allow sufficient transmission of the high-frequency power used for plasma etching. In addition, the upper electrode (13) may include components made of aluminum and anodized aluminum, etc.

[0027] A gas inlet (23) for supplying gases for an etching process is disposed on the upper part of the upper electrode (13). The gas inlet (23) is connected to a reaction gas source (25) via a gas supply line (24), and a valve (26) and a mass flow controller (MFC, 27) for flow control are disposed on the gas supply line (24). At this time, the upper electrode (13) can serve as a path for supplying reaction gases into the reaction chamber (11). To this end, the upper electrode (13) may be composed of multiple layers having multiple diffusion holes (13a). Furthermore, the lower part of the upper electrode (13) may have a shower head structure and a hollow structure for uniform distribution of gas.

[0029] The reaction chamber (11) is connected to a specific pressure reduction device (28, e.g., a vacuum pump) through an exhaust pipe (32) disposed in a specific area. Accordingly, the reaction chamber (11) can provide the low internal pressure required for excellent etching characteristics. Additionally, a gate valve (34) is disposed on the side wall of the reaction chamber (11), and a load lock chamber (15) in which a wafer transfer arm (42) is disposed is connected to the gate valve (34).

[0030] Meanwhile, regarding the operation of introducing a wafer into the reaction chamber (11), the pressure of the load lock chamber (15) is reduced to a level similar to the pressure of the reaction chamber (11), and then the wafer is introduced from the load lock chamber (15) to the reaction chamber (11) using the wafer transfer arm (42). Afterward, the wafer transfer arm (42) is moved from the reaction chamber (11) to the load lock chamber (15), and then the gate valve (34) is closed.

[0032] Figure 2 is an enlarged view showing part A of Figure 1, and Figure 3 is an enlarged view showing part B of Figure 2.

[0034] Referring to FIGS. 2 and 3, an electrostatic chuck (100) according to an exemplary embodiment includes an electrostatic chuck body (110), an adhesive layer (120), a ceramic puck (130), and a sealing member (140).

[0036] The electrostatic chuck body (110) may be provided with a stepped portion (112) that protrudes radially at the bottom. As an example, the electrostatic chuck body (110) may be made of aluminum. As an example, a protective layer (114) may be provided on the surface of the electrostatic chuck body (110). The protective layer (114) may be composed of aluminum oxide as an example.

[0038] The adhesive layer (120) is disposed on the upper surface of the electrostatic chuck body (110). As an example, the adhesive layer (120) serves to bond a ceramic puck (130) to the upper surface of the electrostatic chuck body (120). Meanwhile, the adhesive layer (120) may be a ceramic bond.

[0040] The ceramic puck (130) is bonded to the adhesive layer (120) and positioned so that its edge protrudes from the upper surface of the electrostatic chuck body (110). As an example, a wafer is placed on the upper surface of the ceramic puck (130) during the process.

[0042] The sealing member (140) is positioned between the edge of the step portion (112) and the ceramic puck (130) to prevent the penetration of reaction gas into the adhesive layer (120). As an example, the sealing member (140) may be composed of any one of a metal material, a ceramic material, a metal-ceramic composite, and a polymer-ceramic composite. Meanwhile, if the sealing member (140) is composed of a metal material, the sealing member (140) may be made of any one of aluminum and stainless steel. And, if the sealing member (140) is composed of a ceramic material, the sealing member (140) may be made of any one of aluminum nitride (AlN), aluminum oxide (Al2O3), yttrium oxide (Y2O3), silicon oxide (SiO2), silicon carbide (SiC), and YAG (Yttrium Aluminum Garnet). Meanwhile, if the sealing member (140) is composed of a metal-ceramic composite, the sealing member (140) may be made of an aluminum-silicon carbide composite material. Also, if the sealing member (140) is composed of a polymer-ceramic composite, the sealing member (140) may be made of either a silicon-aluminum oxide composite or a silicon-aluminum nitride composite material.

[0043] Additionally, the sealing member (140) may be provided with a coating layer (142) on its outer surface. As an example, the coating layer (142) may be composed of either a metal oxide including a single rare earth oxide (Al2O3, Y2O3, YAG, ZrO2, TiO2, etc.) or a multilayer heterogeneous metal oxide (Al2O3-Y2O3, Al2O3-TiO2, etc.).

[0044] The coating layer (142) can be formed through an atomic layer deposition process or a chemical vapor deposition process. As an example, when manufacturing the electrostatic chuck (100), a sealing member (140) can be installed between the electrostatic chuck body (110) and the ceramic puck (130), and then the coating layer (142) can be formed by an atomic layer deposition (ALD) method. At this time, the coating layer (142) can be deposited on the sealing member (140) by supplying a coating material in the form of a gas. Accordingly, the coating layer (142) can be formed to block the space between the sealing member (140) and the ceramic puck (130), and the space between the sealing member (140) and the electrostatic chuck body (110).

[0045] Meanwhile, the sealing member (140) may have a circular ring shape, and as an example, may have a rectangular cross-section. Additionally, the sealing member (140) is inserted into the space located between the stepped portion (112) of the electrostatic chuck body (110) and the lower edge of the ceramic puck (130) to prevent the penetration of reaction gas into the adhesive layer (120). Meanwhile, as illustrated in more detail in FIG. 4, the sealing member (140) may have a circular ring shape formed by assembling a plurality of unit members (141). As an example, the plurality of unit members (141) may have a joining portion (141a) formed with a step at the mutually joined portion. For example, the plurality of unit members (141) may be composed of three, and joining portions (141a) may be provided at both ends of the three unit members (141). And, multiple unit members (141) can be combined by arranging the joints (141a) facing each other in an offset manner vertically.

[0047] As described above, since the sealing member (140) is composed of any one of a metal material, a ceramic material, a metal-ceramic composite, and a polymer-ceramic composite, the thermal conductivity can be improved and the corrosion resistance can be improved. Accordingly, the frequency of replacement of the sealing member (140) can be reduced. Also, the temperature at the edge of the electrostatic chuck (100) can be prevented from rising excessively. In addition, since a coating layer (142) is provided on the outer surface of the sealing member (140), the contact area between the sealing member (140), the electrostatic chuck body (120), and the ceramic puck (130) can be increased to improve thermal conductivity. Furthermore, the penetration of reaction gas into the adhesive layer (120) can be prevented.

[0049] FIG. 5 is a perspective view showing a sealing member provided in an electrostatic chuck according to an exemplary embodiment.

[0051] Referring to FIG. 5, the sealing member (240) may have a circular ring shape formed by assembling a plurality of unit members (241). As an example, the plurality of unit members (241) may have a joining portion (241a) formed with a step at the mutually joined portion. For example, the plurality of unit members (241) may be composed of three, and joining portions (241a) may be provided at both ends of the three unit members (241). Furthermore, the plurality of unit members (241) may be joined by arranging the joining portions (241a) facing each other in an offset manner in the thickness direction of the sealing member (240). In other words, the joining portions (241a) may be arranged to overlap each other in the thickness direction of the sealing member (240).

[0053] FIG. 6 is a configuration diagram showing an electrostatic chuck according to an exemplary embodiment.

[0055] Referring to FIG. 6, the sealing member (340) may be composed of a first sealing member (341) having a first inclined surface (341a) at the upper end and a second sealing member (342) having a second inclined surface (342a) at the lower end. Meanwhile, the first inclined surface (341a) and the second inclined surface (342a) may be in close contact. As an example, the sealing member (340) may be installed by first mounting the second sealing member (342) between the ceramic puck (130) and the stepped portion (112) of the electrostatic chuck body (110), and then inserting the first sealing member (341) into the lower part of the second sealing member (342). Afterward, a coating layer (343) may be formed on the sealing member (340). In this way, the sealing member (340) is installed so that the first inclined surface (341a) and the second inclined surface (342a) are in close contact, thereby the first sealing member (341) generates a pressing force toward the stepped portion (112) and the second sealing member (342) generates a pressing force toward the ceramic puck (130), so that the sealing member (340) can be installed more firmly between the ceramic puck (130) and the stepped portion (112) of the electrostatic chuck body (110).

[0057] FIG. 7 is a configuration diagram showing an electrostatic chuck according to an exemplary embodiment.

[0059] Referring to FIG. 7, a sealing member (440) is positioned on the upper surface of a heat pad (450) that is positioned on the upper surface of a stepped portion (112). The heat pad (450) is positioned on the upper surface of the stepped portion (112) of the electrostatic chuck body (110), and the sealing member (440) may have an installation groove (441) in which an O-ring (442) is installed at the lower end. Meanwhile, a coating layer (443) may be formed on the outer surface of the sealing member (440). The coating layer (443) may be formed after the sealing member (440) is installed to be positioned on the upper surface of the heat pad (450). Subsequently, the O-ring (442) may be installed to be inserted into the installation groove (441).

[0061] FIG. 8 is a configuration diagram showing an electrostatic chuck according to an exemplary embodiment.

[0063] Referring to FIG. 6, the sealing member (540) may be provided with a plurality of protrusions (541) on at least one of the upper surface and the lower surface. The plurality of protrusions (541) may be spaced apart from each other, and the height of the protrusions (541) may be 5 μm to 20 μm. Meanwhile, a coating layer (542) may be formed on the upper surface and the lower surface of the sealing member (540) to cover the protrusions (541). Additionally, the coating layer (542) may be formed after the sealing member (540) is mounted between the ceramic puck (130) and the stepped portion (112) of the electrostatic chuck body (110).

[0064] Meanwhile, the coating layer (542) can be formed through an atomic layer deposition process or a chemical vapor deposition process. As an example, when manufacturing the electrostatic chuck (100), a sealing member (540) can be installed between the electrostatic chuck body (110) and the ceramic puck (130), and then the coating layer (542) can be formed by an atomic layer deposition (ALD) method. At this time, the coating layer (542) can be deposited on the sealing member (540) by supplying a coating material in the form of a gas. Accordingly, the coating layer (542) can be formed to block the space between the sealing member (540) and the ceramic puck (130), and the space between the sealing member (540) and the electrostatic chuck body (110).

[0065] Meanwhile, if the protrusion (541) is not provided, and the coating layer (542) is formed to have a thickness of 5 μm or more, the coating layer (542) is not formed uniformly, and parts with thick and thin thicknesses of the coating layer (542) may occur, causing curvature in the coating layer (542). In such cases, reaction gas may penetrate through the space between the sealing member (540) and the ceramic puck (130), and between the sealing member (540) and the body (110). Therefore, to prevent the space between the sealing member (540) and the ceramic puck (130), and between the sealing member (540) and the body (110) from widening, the protrusion (541) is placed to ensure that the coating is uniformly applied using an atomic layer deposition (ALD) method.

[0067] FIG. 9 is a configuration diagram showing an electrostatic chuck according to an exemplary embodiment.

[0069] Referring to FIG. 9, an electrostatic chuck (600) according to an exemplary embodiment includes an electrostatic chuck body (610), a first adhesive layer (620), a heater (630), a second adhesive layer (640), a ceramic puck (650), and a sealing member (660).

[0071] The electrostatic chuck body (610) may be provided with a stepped portion (612) that protrudes radially at the bottom. As an example, the electrostatic chuck body (610) may be made of aluminum. As an example, a protective layer (614) may be provided on the surface of the electrostatic chuck body (610). The protective layer (614) may be composed of aluminum oxide as an example.

[0073] The first adhesive layer (620) is disposed on the upper surface of the electrostatic chuck body (610). As an example, the first adhesive layer (620) serves to bond a heater (630) to the upper surface of the electrostatic chuck body (620). Meanwhile, the first adhesive layer (620) may be a ceramic bond.

[0075] The heater (630) is bonded to the first adhesive layer (620) and can perform the function of heating a wafer that is placed on top of the ceramic puck (650). Meanwhile, the heater (630) may have a size smaller than that of the ceramic puck (650) and may be positioned so as not to protrude from the upper surface of the electrostatic chuck body (610).

[0077] The second adhesive layer (640) is placed on the upper surface of the heater (630). As an example, the second adhesive layer (640) serves to adhere the ceramic puck (650) to the upper surface of the heater (630). Meanwhile, the second adhesive layer (640) may be a ceramic bond.

[0079] The ceramic puck (650) is bonded to the second adhesive layer (640) and positioned so that its edge protrudes from the upper surface of the electrostatic chuck body (610). As an example, a wafer is placed on the upper surface of the ceramic puck (650) during the process.

[0081] The sealing member (660) is positioned between the edge of the step portion (612) and the ceramic puck (650) to prevent the penetration of reaction gas into the first and second adhesive layers (620, 640). As an example, the sealing member (660) may be composed of any one of a metal material, a ceramic material, a metal-ceramic composite, and a polymer-ceramic composite. Meanwhile, if the sealing member (660) is composed of a metal material, the sealing member (660) may be made of any one of aluminum and stainless steel. And, if the sealing member (660) is composed of a ceramic material, the sealing member (660) may be made of any one of aluminum nitride (AlN), aluminum oxide (Al2O3), yttrium oxide (Y2O3), silicon oxide (SiO2), silicon carbide (SiC), and YAG (Yttrium Aluminum Garnet). Meanwhile, if the sealing member (660) is composed of a metal-ceramic composite, the sealing member (660) may be made of an aluminum-silicon carbide composite material. Also, if the sealing member (660) is composed of a polymer-ceramic composite, the sealing member (660) may be made of either a silicon-aluminum oxide composite or a silicon-aluminum nitride composite material.

[0082] Additionally, the sealing member (660) may be provided with a coating layer (662) on its outer surface. The coating layer (662) may be composed of, for example, a metal oxide including a single rare earth oxide (Al2O3, Y2O3, YAG, ZrO2, TiO2, etc.) and a multilayer heterogeneous metal oxide (Al2O3-Y2O3, Al2O3-TiO2, etc.). The coating layer (662) may be formed through an atomic layer deposition process or a chemical vapor deposition process.

[0083] Meanwhile, the sealing member (660) may have a circular ring shape, and as an example, may have a rectangular cross-section. Additionally, the sealing member (660) is inserted into the space located at the lower edge of the electrostatic chuck body (610) and the stepped portion (612) and the ceramic puck (650) to prevent the penetration of reaction gas into the first and second adhesive layers (620, 640). Meanwhile, the sealing member (660) may have a circular ring shape formed by assembling a plurality of unit members. As an example, the plurality of unit members may have a joining portion formed with a step at the mutually joined portion. For example, the plurality of unit members may consist of three, and joining portions may be provided at both ends of the three unit members. Furthermore, the plurality of unit members may be joined by arranging the joining portions facing each other in an up-and-down offset manner.

[0085] As described above, since the sealing member (660) is composed of any one of a metal material, a ceramic material, a metal-ceramic composite, and a polymer-ceramic composite, the thermal conductivity can be improved and the corrosion resistance can be improved. Accordingly, the frequency of replacement of the sealing member (660) can be reduced. Also, it is possible to prevent the temperature at the edge of the electrostatic chuck (600) from rising excessively. In addition, since a coating layer (662) is provided on the outer surface of the sealing member (660), the contact area between the sealing member (660), the electrostatic chuck body (610), and the ceramic puck (650) can be increased to improve thermal conductivity. Furthermore, it is possible to prevent the penetration of reaction gas into the first and second adhesive layers (620, 640).

[0087] Although embodiments of the present invention have been described in detail above, the scope of the present invention is not limited thereto, and it will be obvious to those skilled in the art that various modifications and variations are possible within the scope of the technical concept of the present invention as described in the claims. Explanation of the symbols

[0088] 100, 600 : Electrostatic chuck 110, 610: Electrostatic chuck body 120: Adhesive layer 130 : Ceramic Puck 140, 240, 340, 540, 540, 660 : Sealing member 620: First adhesive layer 630 : Heater 640 : Second adhesive layer 650 : Ceramic Puck

Claims

Claim 1 An electrostatic chuck comprising: an electrostatic chuck body having a stepped portion protruding from a lower portion; an adhesive layer disposed on the upper surface of the electrostatic chuck body; a ceramic puck disposed to be adhered to the adhesive layer and having an edge protruding from the upper surface of the electrostatic chuck body; and a sealing member disposed between the stepped portion and the edge of the ceramic puck to prevent the penetration of reaction gas into the adhesive layer; wherein the sealing member has a coating layer on its outer surface, and the coating layer is composed of either a metal oxide including a single rare earth oxide or a multilayer heterogeneous metal oxide; and wherein the sealing member comprises a first sealing member having a first inclined surface inclined at an upper portion and a second sealing member having a second inclined surface that is coupled to the first sealing member and adheres to the first inclined surface. Claim 2 In claim 1, the sealing member is an electrostatic chuck composed of any one of a metal material, a ceramic material, a metal-ceramic composite, and a polymer-ceramic composite. Claim 3 In claim 1, the surface of the electrostatic chuck body is provided with a protective layer, and the protective layer is made of aluminum oxide material. Claim 4 In claim 1, the sealing member is an electrostatic chuck having a circular ring shape. Claim 5 In paragraph 4, the sealing member is an electrostatic chuck having a circular ring shape formed by assembling a plurality of unit members. Claim 6 In paragraph 5, the electrostatic chuck is provided with a coupling portion formed with a step at the mutually coupled portion of the plurality of unit members. Claim 7 delete Claim 8 An electrostatic chuck comprising: an electrostatic chuck body having a stepped portion protruding from a lower portion; an adhesive layer disposed on the upper surface of the electrostatic chuck body; a ceramic puck disposed to be adhered to the adhesive layer and having an edge protruding from the upper surface of the electrostatic chuck body; and a sealing member disposed between the stepped portion and the edge of the ceramic puck to prevent the penetration of reaction gas into the adhesive layer; wherein the sealing member has a coating layer on its outer surface, the coating layer is composed of either a metal oxide including a single rare earth oxide or a multilayer heterogeneous metal oxide, the sealing member is disposed on a heat pad disposed on the upper surface of the stepped portion of the electrostatic chuck body, and the sealing member has an installation groove in which an O-ring is installed at a lower portion. Claim 9 An electrostatic chuck comprising: an electrostatic chuck body having a stepped portion protruding from a lower portion; an adhesive layer disposed on the upper surface of the electrostatic chuck body; a ceramic puck disposed to be adhered to the adhesive layer and having an edge protruding from the upper surface of the electrostatic chuck body; and a sealing member disposed between the stepped portion and the edge of the ceramic puck to prevent the penetration of reaction gas into the adhesive layer; wherein the sealing member has a coating layer on its outer surface, the coating layer is composed of either a metal oxide including a single rare earth oxide or a multilayer heterogeneous metal oxide, and a plurality of protrusions are provided on at least one of the upper and lower surfaces of the sealing member. Claim 10 In claim 9, the above-mentioned protrusion is an electrostatic chuck composed of a coating layer having a height of 5㎛ to 20㎛.

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