Interchangeable electrostatic chuck outer ring for edge arc mitigation

Abstract

Embodiments disclosed herein include an apparatus for processing a substrate. More specifically, embodiments of the present disclosure provide a substrate support assembly including an electrostatic chuck (ESC) assembly. The ESC assembly includes a cooled base having a top surface and an outer diameter sidewall, and an ESC having a substrate support surface, a bottom surface and an outer diameter sidewall, the bottom surface of the ESC being bonded to the top surface of the cooled base by an adhesive layer. The substrate support assembly includes a block ring disposed around each outer diameter sidewall of the cooled base and the ESC, the block ring shielding an interface between the bottom surface of the ESC and the top surface of the cooled base.

Description

[Technical Field]

[0001] FIELD OF THE DISCLOSURE

[0001] Embodiments of the present disclosure generally relate to apparatus and methods for manufacturing semiconductor devices. More particularly, the apparatus disclosed herein relates to an electrostatic chuck assembly for use in a plasma processing chamber.

[0002] [Related Technology]

[0002] Semiconductor substrates are processed for a variety of applications, including the fabrication of integrated devices and microdevices. One such processing device is a plasma processing chamber. During processing, the substrate is placed on an electrostatic chuck assembly within the plasma processing chamber. The electrostatic chuck assembly may include an electrostatic chuck, a cooling base, an equipment plate, and / or a base. The electrostatic chuck (ESC) may include a chucking electrode for biasing the substrate to the electrostatic chuck.

[0003]

[0003] A plasma is formed in a plasma processing chamber for processing a substrate. To obtain good and consistent results, strict control over the plasma morphology across the substrate as well as the substrate temperature is used during plasma processing. Temperature uniformity is provided by multiple heaters in the ESC along with a cooled base. The plasma morphology is influenced by the electrodes in the ESC and by the shape of the ESC (i.e., the process ring) facing the plasma. Process skew can occur due to plasma coupling to the ESC and / or temperature non-uniformity across the ESC, adversely affecting process performance.

[0004] Furthermore, during processing, the plasma can form a circuit between the electrostatic chuck assembly and the chamber wall, resulting in arcing. Arcing from the electrostatic chuck assembly to ground or from the edge ring to the ESC cooling base can damage the substrate or alter the plasma in a way that could lead to processing defects, negatively impacting processing performance. Edge arcing is one of the main points for arcing in high-power ESCs and can be mitigated by using coatings around the ESC periphery. However, these coatings have many problems, including being easily damaged and corroded. Such coatings are porous, prone to cracking, and difficult and expensive to replace.

[0005]

[0005] Thus, there is a need for improved chamber designs to improve processing performance. Summary of the Invention

[0006] The present disclosure generally includes a substrate support assembly comprising an electrostatic chuck (ESC) assembly. The ESC assembly includes a cooled base having a top surface and an outer diameter sidewall, and an ESC having a substrate support surface, a bottom surface, and an outer diameter sidewall, the bottom surface of the ESC being bonded to the top surface of the cooled base by an adhesive layer. The substrate support assembly also includes block rings disposed around each outer diameter sidewall of the cooled base and the ESC, the block rings shielding the interface between the bottom surface of the ESC and the top surface of the cooled base.

[0007]

[0007] Embodiments of the present disclosure may further provide a substrate support assembly including an electrostatic chuck (ESC) assembly. The ESC assembly includes an ESC having a substrate support surface and a bottom surface, and a cooled base disposed below the bottom surface of the ESC. A portion of the bottom surface of the ESC extends horizontally beyond an upper surface of the cooled base, an equipment plate is disposed below the cooled base, where the bottom surface of the cooled base extends horizontally beyond the equipment plate, an insulating plate is disposed below the equipment plate, where a portion of an upper surface of the insulating plate extends horizontally beyond the bottom surface of the cooled base, and a block ring is disposed between the bottom surface of the ESC, which extends horizontally beyond the upper surface of the cooled base, and an upper surface of the insulating plate, which extends horizontally beyond the bottom surface of the cooled base, and the block ring surrounds the cooled base.

[0008]

[0008] Embodiments of the present disclosure may further provide a substrate support assembly including an electrostatic chuck (ESC). The ESC assembly includes an ESC having a substrate support surface and a bottom surface, and a cooling base disposed below the bottom surface of the ESC. A portion of the bottom surface of the ESC extends horizontally beyond an upper surface of the cooling base, an equipment plate is disposed below the cooling base, an insulating plate is disposed below the equipment plate, the bottom surface of the cooling base extends horizontally beyond the equipment plate and the insulating plate, a ground plate is disposed below the insulating plate, and a portion of the ground plate extends horizontally beyond the insulating plate, and a block ring is disposed between the bottom surface of the ESC that extends horizontally beyond the upper surface of the cooling base and the portion of the ground plate that extends horizontally beyond the insulating plate.

[0009]

[0009] So that the above-mentioned features of the present disclosure can be more fully understood, a more particular description of the present disclosure summarized above can be had by reference to embodiments, some of which are illustrated in the accompanying drawings. It should be noted, however, that the accompanying drawings illustrate only exemplary embodiments and should not be considered as limiting the scope of the present invention, as other embodiments may be recognized that are equally effective. [Brief explanation of the drawings]

[0010] [Figure 1] 1 is a schematic cross-sectional view of an exemplary plasma chamber including a substrate support assembly according to an embodiment. [Figure 2] 1 is a schematic cross-sectional view of an exemplary plasma chamber including a substrate support assembly according to an embodiment. [Figure 3] 1 is a schematic cross-sectional view of an exemplary plasma chamber including a substrate support assembly according to an embodiment. [Figure 4] 1 is a schematic cross-sectional view of an exemplary plasma chamber including a substrate support assembly according to an embodiment. [Figure 5] 1 is a schematic cross-sectional view of an exemplary plasma chamber including a substrate support assembly according to an embodiment. [Figure 6] 1 is a schematic cross-sectional view of an exemplary plasma chamber including a substrate support assembly according to an embodiment. DETAILED DESCRIPTION OF THE INVENTION

[0011]

[0016] To facilitate understanding, the same reference numerals have been used, wherever possible, to designate identical elements common to the figures. It is contemplated that elements and features of one embodiment may be beneficially incorporated in other embodiments without further recitation.

[0012] [Detailed explanation]

[0017] Embodiments described herein provide a substrate support assembly that includes a block ring that protects the interface between an electrostatic chuck (ESC) and a cooling base. The block ring also functions as a vacuum-to-atmospheric seal between the block ring and both the ESC and the cooling base, allowing the RF thermal cooling base to remain at atmospheric pressure and advantageously mitigating arcing.

[0013]

[0018] The substrate support assemblies described below can be utilized in etch process chambers, other types of plasma and non-plasma processing chambers, such as physical vapor deposition chambers, chemical vapor deposition chambers, ion implantation chambers, among others, and other systems where protection of a bonding layer disposed between a cooled base and an ESC is desirable.

[0014]

[0019] 1 is a schematic cross-sectional view of an exemplary plasma chamber 100A including a substrate support assembly 101A according to one embodiment. The substrate support assembly 101A can be utilized in many types of plasma processing chambers, such as plasma treatment chambers, annealing chambers, physical vapor deposition chambers, chemical vapor deposition chambers, and ion implantation chambers, among others, as well as other systems in which it is desirable to protect adhesion layers within the substrate support assembly 101A from environmental conditions within the plasma chamber 100A. It is contemplated that the present disclosure can also be utilized to advantage in processing chambers that utilize plasma.

[0015]

[0020] The plasma processing chamber 100A includes sidewalls 104, a bottom 106, and a lid 108 that encloses a processing region 109. A substrate support assembly 101 is positioned in the processing region 109.

[0016]

[0021] The substrate support assembly 101 includes an electrostatic chuck assembly 103 (ESC assembly), a fixture plate 124 , an insulating plate 126 , a ground plate 128 , and a block ring 145 .

[0017]

[0022] The ESC assembly 103 includes an electrostatic chuck (ESC) 110 and a cooling base 112. In certain embodiments, the ESC assembly 103 may be surrounded by a quartz process kit (not shown). The ESC 110 is bonded to the cooling base 112 using an adhesive layer 114. The ESC 110 has a substrate support surface 116, a bottom surface 118, and a drop-off formed on the support surface 116 to form a ledge 113 that supports an edge ring 120. The edge ring 120 extends horizontally beyond the periphery of the ESC 110. In one embodiment, the ESC 110 is made from a dielectric material in which a chuck electrode 129 is embedded. The dielectric material may be a ceramic material, such as alumina (Al2O3), aluminum nitride (AlN), or other suitable material. Alternatively, the dielectric material of the ESC 110 may be made from a polymer, such as polyimide, polyetheretherketone, polyaryletherketone, or the like.

[0018]

[0023] A top surface 122 of the cooling base 112 is bonded to a bottom surface 118 of the ESC 110 using an adhesive layer 114. The adhesive layer 114 may include an epoxy-containing material, a silicone-containing material, an acrylic-containing material, or other material suitable for bonding the ESC 110 to the cooling base 112. A portion 115 of the ESC 110 extends horizontally beyond the top surface 122 of the cooling base 112. Stated another way, the ESC 110 is wider than the cooling base 112.

[0019]

[0024] The equipment plate 124 is disposed below the cooling base 112. The equipment plate 124, supported by a grounded plate 128, is configured to facilitate electrical, cooling, heating, and gas connections with the substrate support assembly 101A. The grounded plate 128 is supported by the processing chamber bottom 106. The insulating plate 126 insulates the equipment plate 124 from the grounded plate 128. In other words, the insulating plate 126 is disposed above the grounded plate 128 and surrounds the equipment plate 124. There may be an optional gap 125 defined between the equipment plate 124 and the insulating plate 126. The distance of the gap 125 may be between 0.002 and 0.010 inches. The gap 125 helps to slow heat transfer between the equipment plate 124 and the insulating plate 126. The upper surface 117 of the insulating plate 126 extends horizontally beyond the cooling base 112. In other words, the insulating plate 126 is wider than the cooling base 112 .

[0020]

[0025] The chucking electrode 129 of the ESC 110 may be configured as a unipolar or bipolar electrode, or may have any other suitable arrangement. The chucking electrode 129 is coupled by an RF filter (not shown) to a chucking power supply 132, which provides DC power for electrostatically clamping a substrate to the support surface 116 of the ESC 110.

[0021]

[0026] The ESC 110 may optionally include one or more resistive heaters 134 embedded therein. The resistive heaters 134 are utilized to raise the temperature of the ESC 110 to a processing temperature appropriate for processing a substrate disposed on the support surface 116. The resistive heaters 134 are coupled to an optional heater power supply 136 via the fixture plate 124. The heater power supply 136 may provide 500 watts or more of power to the resistive heaters 134. The heater power supply 136 includes a controller (not shown) utilized to control operation of the heater power supply 136, which is typically configured to heat the substrate to a predetermined temperature. In one embodiment, the resistive heaters 134 include multiple laterally separated heating zones, and the controller enables preferential heating of at least one of the resistive heaters 134 relative to resistive heaters 134 located in one or more other zones. For example, the resistive heaters 134 may be arranged concentrically in multiple separated heating zones. The resistive heater 134 maintains the substrate at a processing temperature suitable for processing. In one embodiment, the processing temperature is about -50°C or less. For example, the processing temperature is between about -50°C and about -150°C. In yet another example, the processing temperature is greater than about -50°C. For example, the processing temperature is between about -50°C and about +150°C.

[0022]

[0027] The cooling base 112 includes at least one cooling zone 139, each coupled to a coolant supply 140. The at least one cooling zone 139 may be arranged concentrically or in any other suitable manner. For example, an inner zone may be provided below the substrate support surface 116, while an outer zone may be provided extending along the periphery and possibly below the edge ring 120.

[0023]

[0028] The facilities plate 124 may include optional cooling channels (not shown), which may be coupled to an optional coolant supply 142. If present, the coolant supply 142 provides a coolant capable of maintaining an ambient temperature of, in one example, about 25°C to about 35°C. The coolant supplied by the coolant supply 142 is a heat transfer fluid, and in some examples, a refrigerant. The coolant supply 142 provides a cooling material that circulates through the cooling channels (not shown) of the facilities plate 124. The coolant flowing through the coolant channels may maintain the facilities plate 124 at a predetermined ambient temperature, which may assist in maintaining the insulation plate 126 at a predetermined ambient temperature.

[0024]

[0029] In one embodiment, a block ring 145 may be disposed between the ESC 110 and the top surface 117 of the insulating plate 126, which extends through the cooling base 112 on either side of the substrate support assembly 101A. Stated another way, the block ring 145 is disposed around the outer diameter sidewall 147 of the cooling base 112. In one example, the block ring 145 is made of ceramic or other dielectric material. In one embodiment, the block ring 145 forms a vacuum seal with the ESC 110 via a first seal 150. The block ring 145 forms a vacuum seal with the insulating plate 126 using a second seal 152. There is a top gap 154 ​​between the ESC 110 and the block ring 145, and a bottom gap 156 between the ESC 110 and the insulating plate 126. Thus, the block ring 145 does not contact the ESC 110 or the insulating plate 126. In other words, the periphery of the cooling base 112 is completely isolated by the vacuum seal. Alternatively, the block ring 145 may be sealed to the ESC 110 and the equipment plate 124 using a bonding material instead of a seal. The bonding material may be silicone-based, epoxy, or the like. Thus, the block ring 145 allows a relatively high pressure, such as ambient pressure, to be available within the portion of the substrate support assembly 101 located inside the block ring 145, which also mitigates potential arcing within the substrate support assembly 101.

[0025]

[0030] In some embodiments, components of the substrate support assembly 101A may be coupled to one another using fasteners (not shown). For example, the ground plate 128 may be coupled to the insulating plate 126 using fasteners, the insulating plate may be coupled to the facilities plate 124 using fasteners, and the insulating plate may be coupled to the cooling base 112 using fasteners.

[0026]

[0031] Advantageously, the block ring 145 forms a vacuum seal with the ESC 110 such that the outer diameter of the cooling base 112 is isolated. In other words, the outer diameter of the cooling base 112 and the outer diameter of the ESC 110 are on opposite sides of the vacuum seal, while the block ring 145 acts as a plasma blocker to prevent erosion of the bond layer 114 between the ESC 110 and the cooling base 112, thereby allowing the RF thermal cooling base 112 to remain fully at atmospheric pressure, thus advantageously mitigating potential arcing.

[0027]

[0032] 2 is a schematic cross-sectional view of an exemplary plasma chamber 100B including a substrate support assembly 101B according to one embodiment. The substrate support assembly 101B is similar to the substrate support assembly 101A, but also includes a block ring 145 disposed around a portion of the periphery of the ESC 110, with a gap 158 formed between the top of the ledge 113 and the edge ring 120.

[0028]

[0033] FIG. 3 is a schematic cross-sectional view of an exemplary plasma chamber 100C including a substrate support assembly 101C according to one embodiment. The substrate support assembly 101C is similar to the substrate support assembly 101A, except that the insulating plate 126 does not surround the equipment plate 124. As shown in FIG. 3, the block ring 145 shields the gap between the equipment plate 124 and the cooling base 112, ensuring that the equipment plate 124 does not have a direct line of sight to the sidewall of the plasma chamber 100C, thereby reducing potential arcing between them. Advantageously, this eliminates the bottom gap 156 (FIG. 1) and allows for better control of the distance of the top gap 154, since the cooling base 112 is located on the shoulder of the block ring 145. Additionally, the sealing force of the ESC 110 is reduced because only the force of the first seal 150 is transmitted to the ESC 110. Additionally, corrosion of the insulating plate 126 and second seal 152 is reduced because they are farther away from the substrate support surface 116 (i.e., the processing region). In some embodiments, the block ring 145 may be coupled to the cooling base 112 and the insulating plate 126 via fasteners 155.

[0029]

[0034] 4 is a schematic cross-sectional view of an exemplary plasma chamber 100D including a substrate support assembly 101D according to an embodiment. The substrate support assembly 101D is similar to the substrate support assembly 101C, but also includes a block ring 145 disposed around a portion of the periphery of the ESC 110, with a gap 158 formed between the top of the ledge 113 and the edge ring 120.

[0030]

[0035] FIG. 5 is a schematic cross-sectional view of an exemplary plasma chamber 100E including a substrate support assembly 101E according to one embodiment. The substrate support assembly 101E is similar to the substrate support assemblies 101A-101D, except that the insulating plate 126 is flush with the facility plate 124. As shown in FIG. 5, the shoulder of the block ring 145 shields the gap between the ground plate 128 and the cooled base 112, ensuring that the facility plate 124 does not have a direct line of sight to the sidewall of the plasma chamber 100E, thereby reducing potential arcing between them. The block ring 145 may be coupled to the cooled base using a first fixture 155 and to the ground plate 128 using a second fixture. Advantageously, this eliminates the bottom gap (FIG. 1) and allows for better control of the distance of the top gap 154 ​​because the cooled base 112 is at the shoulder of the block ring 145. Also, the sealing force of the ESC 110 is reduced because only the force of the first seal 150 is transferred to the ESC 110. Furthermore, corrosion of the insulating plate 126 is reduced because the insulating plate 126 is fully transferred to atmospheric pressure. In some embodiments, the block ring 145 may be coupled to the cooling base 112 and the insulating plate 126 via fasteners 155.

[0031]

[0036] 6 is a schematic cross-sectional view of an exemplary plasma chamber 100F including a substrate support assembly 101F in accordance with an embodiment. The substrate support assembly 101F is similar to the substrate support assembly 101E, but further includes a block ring 145 disposed therein with a gap 158 formed between the top of the ledge 113 and the edge ring 120.

Claims

1. 1. An electrostatic chuck (ESC) assembly comprising: a cooling base having a top surface and an outer diameter sidewall; ESC HAVING SUBSTRATE SUPPORT SURFACE, BOTTOM SURFACE AND OUTER DIAMETER SIDEWALL an electrostatic chuck (ESC) assembly, wherein the bottom surface of the ESC is coupled to the top surface of the cooling base by an adhesive layer; an equipment plate disposed below the cooling base; an insulating plate disposed below the equipment plate; a block ring disposed around each outer diameter sidewall of the cooling base and the ESC, the block ring shielding the interface between the bottom surface of the ESC and the top surface of the cooling base, forming a vacuum seal with the bottom surface of the ESC, forming a vacuum seal with the cooling base, being flush with the bottom surface of the cooling base, providing spacing between the insulation plate and the facilities plate, and isolating the cooling base from vacuum; A substrate support assembly comprising:

2. 1. An electrostatic chuck (ESC) assembly comprising: a cooling base having a top surface and an outer diameter sidewall; ESC HAVING SUBSTRATE SUPPORT SURFACE, BOTTOM SURFACE AND OUTER DIAMETER SIDEWALL an electrostatic chuck (ESC) assembly, wherein the bottom surface of the ESC is coupled to the top surface of the cooling base by an adhesive layer; a block ring disposed around each outer diameter sidewall of the cooling base and the ESC, the block ring shielding an interface between the bottom surface of the ESC and the top surface of the cooling base; an equipment plate disposed below the cooling base; an insulating plate surrounding the equipment plate, a portion of an upper surface of the insulating plate extending horizontally beyond the upper surface of the cooling base; A substrate support assembly comprising:

3. The substrate support assembly of claim 2 , further comprising a ground plate disposed below the insulating plate.

4. The substrate support assembly of claim 2 , further comprising a top gap between the block ring and the bottom surface of the ESC, and a bottom gap between the block ring and the top surface of the insulating plate.

5. The substrate support assembly of claim 2 , wherein the blocking ring forms a seal with the ESC and the insulating plate via a bonding material.

6. 3. The substrate support assembly of claim 2, wherein the block ring forms a vacuum seal with an ESC via a first seal, and the block ring forms a vacuum seal with the insulating plate via a second seal.

7. The substrate support assembly of claim 6 , wherein the ESC and the block ring are on opposite sides of the first encapsulation.

8. The substrate support assembly of claim 1 , wherein the cooling base comprises at least one cooling zone each coupled to a cooling supply.

9. The substrate support assembly of claim 1 , wherein the block ring is made of a ceramic material.

10. 1. An electrostatic chuck (ESC) assembly comprising: an ESC having a substrate support surface and a bottom surface; a cooling base disposed below the bottom surface of the ESC, a portion of the bottom surface of the ESC extending horizontally beyond a top surface of the cooling base; an electrostatic chuck (ESC) assembly having an equipment plate disposed below the cooling base, the bottom surface of the cooling base extending horizontally beyond the equipment plate; an insulating plate disposed below the equipment plate, a portion of an upper surface of the insulating plate extending horizontally beyond the bottom surface of the cooling base; a block ring disposed between the bottom surface of the ESC, which extends horizontally beyond the top surface of the cooling base, and the top surface of the insulating plate, which extends horizontally beyond the bottom surface of the cooling base, the block ring surrounding the cooling base; A substrate support assembly comprising:

11. The substrate support assembly of claim 10 , wherein the block ring is coupled to the insulating plate and the cooling base via fasteners.

12. 11. The substrate support assembly of claim 10, wherein the block ring forms a vacuum seal with an ESC via a first seal, and the block ring forms a vacuum seal with the insulating plate via a second seal.

13. The substrate support assembly of claim 10 , further comprising an upper gap between the block ring and the bottom surface of the ESC that extends horizontally beyond the top surface of the cooling base.

14. The substrate support assembly of claim 10 , wherein the block ring forms a seal with the bottom surface of the ESC and the insulating plate, which extends horizontally beyond the top surface of the cooling base, via a block of material.

15. The substrate support assembly of claim 10 , further comprising a ground plate disposed below the insulating plate.

16. 1. An electrostatic chuck (ESC) assembly comprising: an ESC having a substrate support surface and a bottom surface; a cooling base disposed below the bottom surface of the ESC, a portion of the bottom surface of the ESC extending horizontally beyond a top surface of the cooling base; an electrostatic chuck (ESC) assembly having an equipment plate disposed below the cooling base; an insulating plate disposed below the equipment plate; a ground plate disposed below the insulating plate, a portion of the ground plate extending horizontally beyond the insulating plate; a block ring disposed between the bottom surface of the ESC that extends horizontally beyond the top surface of the cooling base and the portion of the ground plate that extends horizontally beyond the insulating plate; 1. A substrate support assembly comprising: a substrate support assembly, wherein a bottom surface of the cooling base extends horizontally beyond the facilities plate and the insulating plate;

17. 17. The substrate support assembly of claim 16, wherein the block ring is coupled to the cooling base via a first fixture, and the block ring is coupled to the ground plate with a second fixture.

18. 17. The substrate support assembly of claim 16, wherein the block ring forms a vacuum seal with an ESC via a first seal, and the block ring forms a vacuum seal with the ground plate via a second seal.

19. The substrate support assembly of claim 16 , further comprising an upper gap between the block ring and the bottom surface of the ESC that extends horizontally beyond the top surface of the cooling base.

20. The substrate support assembly of claim 16 , wherein the block ring forms a seal with the bottom surface of the ESC and the ground plate, which extends horizontally beyond the top surface of the cooling base, via a block of material.

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