Combined structure of E-sucker and aluminum-based structure

Abstract

The present disclosure is a method of integrating an electrostatic chuck to a temperature control base. According to an embodiment, a bonding layer is formed between a dielectric body including the electrostatic chuck and the temperature control base. Flow holes extend through the dielectric body and are aligned with flow holes in the temperature control base. The bonding layer is also configured with an opening that is aligned with holes in the dielectric body and the temperature control base. In one aspect, a porous plug can be disposed within the flow holes to protect the bonding layer. In another aspect, a seal is disposed within the flow holes to seal the bonding layer from gases in the flow holes.

Description

Technical Field

[0001] Embodiments of the present disclosure generally relate to a bonding layer for an electrostatic chuck. Background Art

[0002] Electrostatic chucks are used in various manufacturing and processing operations. In semiconductor manufacturing, electrostatic chucks are typically used to support substrates in a processing chamber. Semiconductor manufacturing exposes the substrate support including the electrostatic chuck to the processing chamber environment and to a temperature range between the ambient temperature and the substrate processing temperature. To maintain the substrate temperature at a desired set point, an electrostatic chuck formed of ceramic is coupled to a temperature control base. A conductive bonding material between the ceramic chuck portion and the temperature control base connects the two bodies.

[0003] The substrate support (including the bonding material exposed at any dorsal gas passage extending therethrough at the interface between the electrostatic chuck and the cooling base) is exposed to the process gases and process reaction by-products of the manufacturing process. Some of these gases and by-products can degrade the bonding material when they come into contact with the bonding material. Inconsistencies in the bonding material may also be caused during the manufacture and formation of the bonding material. These variations in adhesion strength and material properties may cause the bonding material to delaminate from the electrostatic chuck and the temperature control base or locally alter the heat transfer through the bonding material, resulting in temperature variations across the chucking surface of the electrostatic chuck. Additionally, the electrostatic chuck and the temperature control base may have different coefficients of thermal expansion. When the temperature of the substrate support increases (such as during a process operation), or when the dielectric body and the temperature control base have different temperatures, the stress in the bonding material increases due to the different thermal expansions of the electrostatic chuck and the temperature control base. When the local stress exceeds the bonding strength of the bonding material, this increase in stress may cause local delamination of the bonding material. Summary of the Invention

[0004] The present disclosure generally relates to a bonding layer for fixing a ceramic body to a metal body. Flow holes extend through the body. Plugs and seals are optionally disposed within the flow holes to protect the bonding layer. In certain embodiments, the bonding layer may include two layers to form a stepped bonding profile. Brief Description of the Drawings

[0005] For a more particular description of the features and structures of the present disclosure as briefly outlined above, reference may be made to the embodiments, some of which are illustrated in the accompanying drawings. However, it will be noted that the accompanying drawings only illustrate exemplary embodiments and should not be considered as limiting the scope of the present disclosure, as the present disclosure may admit other equivalent embodiments.

[0006] Figure 1 is a cross-sectional schematic view of an exemplary substrate support.

[0007] Figures 2A - 2B A cross-sectional view of a bonding structure that fixes an electrostatic chuck and a temperature control member together according to one embodiment.

[0008] Figure 3 A cross-sectional view of a bonding structure that fixes an electrostatic chuck and a temperature control member together according to one embodiment.

[0009] Figure 4 A cross-sectional view of a bonding structure that fixes an electrostatic chuck and a temperature control member together according to one embodiment.

[0010] For the sake of facilitating understanding, the same reference numerals have been used to denote the same elements common to the figures as much as possible. It is contemplated that the elements and features of one embodiment may be beneficially incorporated into other embodiments without undue recitation with respect to the other embodiments. Detailed Description

[0011] The present disclosure is a method of bonding an electrostatic chuck to a temperature control base. According to an embodiment, a bonding layer is formed between a dielectric body including the electrostatic chuck and the temperature control base. Flow holes extend through the dielectric body and are aligned with flow holes in the temperature control base. The bonding layer is configured with openings that are aligned with the holes in the dielectric body and the temperature control base. In one aspect, a porous plug may be disposed within the flow holes to protect the bonding layer from the gases present in the flow holes. In another aspect, a seal is disposed within the flow holes to seal the bonding layer from the gases present in the flow holes.

[0012] Figure 1 A cross-sectional view of an exemplary substrate support in a processing chamber. The substrate support 100 includes a dielectric body 102 and a temperature control base 104, and the dielectric body 102 forms an electrostatic chuck. The dielectric body includes a ceramic material such as alumina or aluminum nitride. The temperature control base 104 includes a metal such as aluminum. The temperature control base 104 is fixed to a cylindrical support post (not shown) that extends through the wall of the processing chamber to support the substrate support 100 thereon. Alternatively, the temperature control base may be fixed to a base on the interior of the chamber. The substrate support 100 generally may have a circular shape, but other shapes capable of supporting a substrate, such as rectangular or oval, may also be utilized. A bonding layer 106 is disposed between the lower surface of the dielectric body 102 facing the temperature control base 104 and the upper surface of the temperature control base 104 facing the dielectric body 102 opposite the cylindrical support post. The substrate W is removably disposed on the upper surface of the dielectric body 102 opposite the bonding layer 106. The bonding layer 106 fixes the dielectric body 102 to and thermally couples it to the temperature control base 104.

[0013] The electrode 108 is disposed within the dielectric body 102. The electrode 108 is connected to a power supply (not shown) that imposes a voltage across the electrode to form an electromagnetic field at the interface between the upper surface of the dielectric body 102 and the substrate W. The electromagnetic field interacts with the substrate W to hold the substrate W against the surface of the dielectric body 102. The electrode may be biased to provide a monopolar or bipolar chuck.

[0014] Channels 110 disposed within the temperature control base 104 circulate a fluid through the temperature control base 104. A fluid (typically a liquid such as flows through the channels 110 and returns to the temperature control unit. In some processes, the fluid is used to cool the temperature control base 104 in order to reduce the temperature of the dielectric body 102 and the substrate W disposed thereon. Conversely, the fluid may be used to raise the temperature of the temperature control base 104 to heat the dielectric body 102 and the substrate W disposed thereon. In other embodiments, a resistive heater (not shown) may be disposed within the temperature control base. In some cases, heat from the resistive heater combined with heat transfer from the temperature control base 104 into the fluid is used to maintain the dielectric body 102 or the substrate W at a set point temperature.

[0015] Flow holes 112 are disposed within the substrate support 100. As Figure 1 shown, the flow holes 112 are formed to extend through the dielectric body 102, the bonding layer 106, and the temperature control base 104. In this configuration, the gas introduced through the flow holes 112 is present in the region between the side of the substrate W facing the dielectric body 102 and the facing surface of the dielectric body 102. The gas is maintained at a pressure sufficient for the gas to serve as a thermal conduction path between the substrate W and the dielectric body 102. A gas source (not shown) is coupled to the flow holes 112. During processing, a gas such as helium flows from the gas source and is delivered via the flow holes 112 to the lower surface of the substrate W (the surface not exposed to the processing region of the chamber). It is known that some gases degrade the bonding layer 106 exposed to the gas at the flow holes 112.

[0016] Figure 2A and Figure 2B are cross-sectional schematic views of the dielectric body 102, the temperature control base 104, and the intermediate bonding layer 106. In Figures 2A - 2B the substrate support 100 includes a dielectric body 102 and a temperature control base 104 similar to those of Figure 1 . Here, the bonding layer 106 includes two partial layers 106a, 106b. In Figures 2A - 2BIn some embodiments, the bonding layers 106a, 106b include sheets of bonding material. The bonding layers 106a, 106b include organic materials such as silicone, acrylic, perfluoropolymers, or combinations thereof, but other materials are also contemplated. In certain embodiments, the bonding layer 306 additionally includes an inorganic material (e.g., aluminum oxide, aluminum nitride, or silicon carbide) to improve specific properties of the bonding layer 306, such as thermal conductivity. The bonding layer 106a is disposed on the surface 208 of the dielectric body 102. The bonding layer 106b is disposed on the facing surface 210 of the temperature control base 104. The bonding layers 106a, 106b are disposed on the surface 210 of the temperature control base 104. The bonding layers 106a, 106b are disposed on the surface 210 of the temperature control base 104 to form a complete bonding layer 106 ( Figure 2B ) are respectively adhered to the dielectric body 102 and the temperature control base 104 ( Figure 2A ), which improves the bonding properties of the bonding material and increases the uniformity of the thickness of the bonding material. The final bonding layer 106 is formed by a curing process. The bonding layer 106 can have a thickness in the range of about 100 microns to 800 microns, but can be thicker or thinner when necessary to achieve the desired material properties, bonding strength, and heat transfer properties between the dielectric body 102 and the temperature control base 104. Although in Figures 2A - 2B In the embodiment of the present invention, a sheet of bonding material is used, but it will be understood that any method capable of forming a bonding layer can be used, such as casting, applying a paste, spraying or molding the bonding material on the surfaces of the respective dielectric body 102 and the temperature control base 104. In addition, a different number of layers can be used to form the bonding layer 106.

[0017] The flow hole 112 extends through the substrate support 100. For ease of description, Figures 2A - 2B 1 , but it will be appreciated that multiple holes may be utilized. The flow hole 112 is formed through the dielectric body 102, the bonding layer 106, and the temperature control base 104. The portion of the flow hole 112 disposed within the temperature control base 104 includes two portions. The first portion extends inwardly from a surface 210 facing the dielectric body 102 toward the center of the body of the temperature control base 104. The first portion extending partially through the temperature control base 104 is a counterbore forming a cylindrical recess 212. The second portion extends from the recess 212 through the remainder of the temperature control base 104 and has a circular cross-section. The first portion and the second portion each have a diameter, wherein the diameter of the second portion is smaller than the diameter of the first portion, as shown in FIG. Figures 2A - 2BAs shown. The bonding layer 106 is arranged to be adjacent to the surface 210 of the temperature control base 104. Openings are formed through each of the bonding layers 106a, 106b, and the openings are aligned with the center of the groove 212, thereby forming holes through each of the bonding layers 106a, 106b. The opening 214 of the bonding layer 106b has a diameter equal to or greater than the diameter of the groove 212. The opening 216 of the bonding layer 106a has a diameter smaller than the diameter of the opening 214. In some embodiments, the opening 216 may have a diameter substantially equal to the diameter of the groove 212. When the bonding layers 106a, 106b are combined as Figure 2B shown, the openings 214, 216 through the bonding layer 106 create a "stepped bond".

[0018] A series of vanes 218 are formed within the dielectric body 102, and they are configured to be aligned with the groove 212 and the openings 214, 216 to partially define the flow holes 112. Figures 2A - 2B Two vanes are shown, and the two vanes together with the adjacent side walls of the dielectric body 102 define three passageways, but the embodiments herein can be practiced with any suitable number of vanes. A plug 220 is optionally disposed within the dielectric body 102 and aligned with the flow hole 112. The plug 220 is formed of a porous material, such as ceramics, which can be alumina or zirconia. The plug 220 has a certain porosity, such as a porosity range between 10% and 80%, which allows gas to pass from the groove 212 through the openings 214, 216 to the passageways between the vanes 218 and be in fluid communication with the region between the substrate W and the dielectric body 102 when the substrate is supported on the dielectric body 102. The plug 220 further prevents particles, ionized particles, or ionized gas from passing through the passageways between the vanes 218 from the processing region and entering the gas volume region defined by the openings 214, 216 when the substrate W is not on the dielectric body 102.

[0019] Figures 2A - 2B The stepped bond shown in [reference] advantageously improves the uniformity of the bonding layer by forming two partial layers and then forming a complete bonding layer. By improving the uniformity of the bonding material, the resistance of the bonding material to degradation due to exposure to process gases is increased. Additionally, across the bonding layer between the dielectric body and the temperature control base, the adhesion is consistent, which prevents local delamination caused by stress due to thermal expansion of one or both of the temperature control base and the dielectric body.

[0020] Figure 3 shows a similar Figure 1 and Figures 2A - 2B such as a schematic cross-section of the substrate support 100. Figure 3 The substrate support 100 contains the same as Figures 1 - 2BIdentical components, which share the same reference numerals and will not be discussed further for the sake of brevity. The bonding layer 306 is disposed between the dielectric body 102 and the temperature control base 104 to fix the dielectric body 102 and the temperature control base 104 together. In Figure 3 the embodiment of, a single sheet of bonding material is used. However, it should be understood that there are other ways of applying the bonding material, such as casting, applying a paste, spraying or molding, or using a multi-layer sheet. The bonding layer 306 includes an organic material, such as silicone, acrylic, perfluoropolymer, or a combination thereof, but other materials capable of forming a bond have also been contemplated. In certain embodiments, the bonding layer 306 additionally includes an inorganic material (e.g., alumina, aluminum nitride, or silicon carbide) to improve certain properties of the bonding layer 306, such as thermal conductivity. An annular opening 302 is formed through the bonding layer 306 and is configured to align with the cylindrical groove 212 and the vane 218, and the cylindrical groove 212 and the vane 218 together with the annular opening 302 partially define the flow hole 112. Similarly, Figure 3 a single flow hole 112 is shown in, but any suitable number of holes may be utilized. The diameter of the opening 302 is smaller than the diameter of the cylindrical groove 212 such that a shoulder is formed by applying the edge of the bonding layer 306 over the groove 212. The shoulder and the opening 302 serve as a choke for the airflow leading to the vane 218 or the plug 220 optionally disposed therein. The opening 302 also has a diameter smaller than the diameter of the plug 220 such that the bonding layer 306 extends beneath the plug 220, as Figure 3 shown. Here, the plug 220 is also used to prevent particles, ionized particles of the material, or ionized gas from the process environment from reaching the bonding material when the substrate W is not present on the dielectric body 102. By extending the bonding layer 306 over the groove 212, the surface area of the temperature control base 104 exposed to the corrosive process gas is reduced, which significantly reduces the corrosion of the metal temperature control base 104.

[0021] Figure 4 is shown similar to Figures 1 - 3a substrate support 100 as such, and the same components share the same reference numerals. For the sake of brevity, the description of the same components will be omitted again here. A bonding layer 406 is disposed between the dielectric body 102 and the temperature control base 104 and secures them together. A single flow hole 112 is shown as being provided in the substrate support 100, but any suitable number can also be utilized. An annular opening 414 is formed through the bonding layer 406 to partially define the flow hole 112. The opening 414 has a diameter substantially larger than that of the cylindrical groove 212. A seal 404 (such as an O-ring) is optionally disposed in the enlarged diameter of the opening 414. The seal 404 is used to seal the bonding layer 406 to isolate it from the gas flowing within the flow hole 112. The seal 404 includes a material capable of withstanding degradation caused by gas chemicals. In certain embodiments, the seal 404 includes a polymer, such as a perfluoropolymer (e.g., or XPE), polytetrafluoroethylene (PTFE), or silicone. Other materials are also contemplated, such as additional petroleum-based polymers. Any material suitable for contact with the process gas flowing in the flow hole 112 can be utilized.

[0022] A plug 420 similar to the plug 220 of FIGS. 2-3 is optionally disposed in the dielectric body 102, adjacent to the vane 218. The plug 420 and the vane 218 can be provided as a single piece. The plug 420 includes a porous material, such as ceramic, where the porosity can have a range, such as a porosity of 10% to 80%, to allow air flow through the plug 420 to the passage defined by the vane 218 in combination with the adjacent sidewall of the dielectric body 102. The plug 420, like the plug 220, is also used to prevent ionized particles of material or ionized gas from the process environment from reaching the bonding material when the substrate W is not present on the dielectric body 102. The plug 420 is configured to receive a ring 408. The ring 408 is disposed adjacent to the seal 404 and contacts both the seal 404 and the plug 420. The ring 408 can include a metal or ceramic material. The ring 408 provides an improved sealing surface for the seal 404. The seal 404 contacts the ring 408 to create a first sealing point. Opposite the ring 408, the seal 404 contacts the temperature control base 104 to create a second sealing point. The first sealing point and the second sealing point prevent gas from bypassing the seal 404 and isolate the bonding layer 406 from the gas within the flow hole 112. The embodiments herein provide improved sealing to protect the bonding layer 406 from process gases, thereby increasing the life and durability of the bonding material.

[0023] In certain embodiments, the bonding material of the bonding layer 406 can be selected to improve one or more desired properties, such as heat transfer or high-temperature adhesion. Some materials with desired properties may in turn have less resistance to degradation due to exposure to the process gas within the flow hole 112. By using such asFigure 4 The shown seal 404 and ring 408, a material with less resistance can be selected for the bonding material because the seal 404 isolates the bonding layer 406 from the process gas. A second seal (not shown) can be provided at the outer periphery of the bonding layer 406, whereby, in combination with the seal 404, the dielectric body 102 and the temperature control base 104, the bonding layer 406 is encapsulated. Thus, the substrate support 100 can have a bonding layer with desired properties without reducing the life and durability of the bonding layer.

[0024] It will be understood that the embodiments disclosed herein are not limited to electrostatic chucks. The embodiments can be practiced with any structure in which a bonding layer is utilized. It will be further understood that the exemplary geometries disclosed herein do not limit the scope of the embodiments. Other geometries of the flow holes and the body have been conceived.

[0025] Although the foregoing is directed to embodiments of the present disclosure, other and further embodiments of the present disclosure can also be designed without departing from the basic scope of the present disclosure, and the scope of the present disclosure is determined by the appended claims.

[0026] List of Element Symbols

[0027] 100 Substrate support

[0028] 102 Dielectric body

[0029] 104 Temperature control base

[0030] 106 Bonding layer

[0031] 106a Bonding layer

[0032] 106b Bonding layer

[0033] 108 Electrode

[0034] 110 Channel

[0035] 112 Flow hole

[0036] 208 Surface

[0037] 210 Surface

[0038] 212 Groove

[0039] 212 Groove

[0040] 214 Opening

[0041] 216 Opening

[0042] 218 Vane

[0043] 220 Plug

[0044] 302 opening

[0045] 306 bonding layer

[0046] 404 seal

[0047] 406 bonding layer

[0048] 408 ring

[0049] 414 opening

[0050] 420 plug

Claims

1. A bonding layer structure, comprising: A first body having a first flow hole passing therethrough and an electrode disposed therein; A second body having a second flow hole passing therethrough and a channel disposed therein; And A bonding layer disposed between the first body and the second body, the bonding layer comprising: A first bonding layer adhered to the first body and having a first opening extending through the first bonding layer; And A second bonding layer directly adhered to the first bonding layer and having a second opening extending through the second bonding layer, wherein the second opening has a second diameter greater than the first diameter of the first opening.

2. The bonding layer structure according to claim 1, wherein the first bonding layer and the second bonding layer comprise sheets of bonding material.

3. The bonding layer structure according to claim 1, wherein the bonding layer comprises an organic material, the organic material comprising silicone resin, acrylic acid or perfluoropolymer.

4. The bonding layer structure according to claim 1, further comprising a porous plug disposed adjacent to the bonding layer.

5. The bonding layer structure according to claim 1, wherein the centers of the first flow hole passing through the first body, the second flow hole passing through the second body, the opening passing through the first bonding layer, and the opening passing through the second bonding layer are aligned along an axis extending therethrough.

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