Process chamber with reduced plasma arcing

Abstract

A processing system includes a chamber body, a substrate support, and a lid assembly. The substrate support is located in the chamber body and includes a first electrode. The lid assembly is positioned above the chamber body and defines a processing volume. The lid assembly includes a faceplate, a second electrode positioned between the faceplate and the chamber body, and an insulating member positioned between the second electrode and the processing volume. A power supply system couples the first electrode and the faceplate and is configured to generate a plasma in the processing volume.

Description

TECHNICAL FIELD

[0001] Embodiments described herein relate to semiconductor manufacturing apparatus and methods. In particular, embodiments described herein relate to plasma processing chambers for semiconductor substrates. BACKGROUND

[0002] Many processing systems employ a lid assembly that includes a stack of one or more insulating rings and one or more electrodes positioned on a chamber body of the processing system. During processing, deposition material can accumulate on the insulating rings, electrodes, and / or in the gap between the electrodes and insulating rings. As the thickness of the deposition material increases, the localized high electric field increases, resulting in arcing inside the chamber body. For example, a charge accumulated on the surface of a substrate undergoing processing within the processing system can arc to the deposited material near the gap between the electrodes and insulating rings. As a result, arcing occurs within the processing chamber. The arcing can detrimentally affect the substrate processing, causing the processing chamber to go offline. Thus, the processing system has increased downtime and reduced productivity.

[0003] Accordingly, there is a need for improved processing systems with reduced arcing. SUMMARY

[0004] In one example, a processing system includes a chamber body, a substrate support disposed in the chamber body, and a lid assembly disposed above the chamber body and defining a processing volume. The lid assembly includes a faceplate, an electrode, and an insulating member. The insulating member is positioned between the electrode and the processing volume of the processing chamber. Further, the electrode is positioned between the faceplate and the chamber body.

[0005] In one embodiment, a lid assembly for a processing system includes a faceplate, an electrode, an insulating ring, and an insulating member. The insulating member is positioned between the electrode and the insulating ring and a processing volume of the processing system. The electrode is positioned between the faceplate and a chamber body of the processing system.

[0006] In one embodiment, a processing chamber includes a chamber body, a substrate support, and a lid assembly. The substrate support is located in the chamber body and includes a first electrode. The lid assembly is located above the chamber body and defines a processing volume within the chamber body. The lid assembly includes a faceplate, a second electrode positioned between the faceplate and the chamber body, and an insulating member. The insulating member is positioned between the second electrode and the processing volume. BRIEF DESCRIPTION OF DRAWINGS

[0007] So that the manner in which the above recited features of the present disclosure can be understood in detail, a brief description of the disclosure can be had by reference to embodiments, some of which are illustrated in the appended drawings. It is to be noted, however, that the appended drawings illustrate only typical embodiments of this disclosure and are therefore not to be considered limiting of its scope, for the disclosure can admit to other equally effective embodiments.

[0008] Figure 1 is a schematic cross-sectional view of a processing system according to one embodiment.

[0009] Figure 2A is a schematic cross-sectional view of a portion of a processing system according to one embodiment.

[0010] Figure 2B is a bottom plan view of an insulating member according to one embodiment.

[0011] Figure 3 is a schematic cross-sectional view of a processing system according to one embodiment.

[0012] Figure 4 is a schematic cross-sectional view of a portion of a processing system according to one embodiment.

[0013] To facilitate an understanding of this disclosure, like reference characters are used throughout the disclosure. The skilled artisan will appreciate that the components disclosed in one embodiment can be advantageously used in other embodiments without specific recitation. DETAILED DESCRIPTION

[0014] Embodiments described herein provide an apparatus for processing semiconductor substrates. In many instances, when processing a substrate, one or more layers of material are deposited on the surface of the substrate and also on other surfaces of the processing system. For example, material can be deposited on the electrodes of a lid assembly, the insulating rings of the lid assembly, and / or the gap between the electrodes and the insulating rings. Over time, the thickness of the deposited material on the various surfaces of the processing chamber increases, thereby increasing the likelihood of arcing occurring within the processing chamber. Arcing can have adverse effects on the substrate processing and / or hardware components, increasing the frequency of scrapped substrates and repair downtime. Moreover, taking the corresponding processing system offline for repair results in decreased productivity of the processing system and increased corresponding production costs.

[0015] Arcing can occur when the thickness of the deposition on the electrodes and the insulating rings is about 1.8 microns or greater. In many cases, the deposition capability of such processing systems is also about 1.8 microns. Thus, in such processing systems, the likelihood of arcing is high. However, limiting the deposition thickness to reduce arcing is difficult because a deposition capability of 1.8 microns or less is challenging for the production of many modern semiconductor devices.

[0016] However, by including an insulating member between the electrode and the insulating ring and the processing volume of the processing system, material build-up on the electrode, the insulating ring, and the gap between the electrode and the insulating ring is reduced or eliminated. Thus, the occurrence of arcing within the processing system is reduced, reducing downtime of the processing system and increasing the productivity of the processing system. Further, the deposition capacity of the corresponding processing system is also increased.

[0017] Figure 1 FIG. 1 is a schematic cross-sectional view of a processing chamber 100 of a processing system according to one or more embodiments. The processing chamber 100 features a chamber body 102, a substrate support 104 disposed within the chamber body 102, and a lid assembly 106 coupled to the chamber body 102 and enclosing the substrate support 104 in a processing volume 120. A substrate 105 is provided to the processing volume 120 through an opening 126, which can be sealed for processing by a door using a valve assembly (not shown). The processing chamber 100 can be particularly one of a chemical vapor deposition (CVD) processing chamber, an atomic layer deposition (ALD) processing chamber, a metal organic chemical vapor deposition (MOCVD) processing chamber, a plasma enhanced chemical vapor deposition (PECVD) processing chamber, or a plasma enhanced atomic layer deposition (PEALD) processing chamber.

[0018] The chamber body 102 includes a chamber wall 103. Further, a liner 101 can be located on the chamber wall 103 such that the liner 101 is between the chamber wall 103 and the processing volume 120. The liner 101 can include aluminum. Alternatively, the liner 101 can include other conductive or insulating materials.

[0019] The lid assembly 106 includes an electrode 108, an insulating ring 110, and a faceplate 112. Further, the lid assembly 106 includes an insulating member 111 located radially inward of the insulating ring 110 and the electrode 108. For example, the insulating member 111 is positioned between the insulating ring 110 and the electrode 108 and the processing volume 120 such that surfaces of the insulating ring 110 and the electrode 108 are not exposed to the processing volume 120. The lid assembly 106 and the substrate support 104 can be used with a processing chamber configured for plasma processing or thermal processing.

[0020] The electrode 108 is disposed adjacent to the chamber body 102 and is positioned between the chamber body 102 and other components of the lid assembly 106. The electrode 108 is a ring-shaped or annular member and can be referred to as a ring electrode. The electrode 108 can be a continuous annulus that encircles the processing volume 120 around a perimeter of the processing chamber 100, or can be discontinuous at selected locations. The electrode 108 can also be a perforated electrode, such as a perforated ring or a mesh electrode. In some examples, the electrode 108 can be electrically isolated from the chamber body 102 by an electrically insulating material, such as ceramic, located between the electrode 108 and the chamber body 102 (e.g., between the electrode 108 and the faceplate 112). Figure 3The insulating ring 310 is electrically isolated from the chamber body 102.

[0021] The insulating ring 110 can be a dielectric material such as ceramic or metal oxide (e.g., aluminum oxide and / or aluminum nitride) that contacts the electrode 108 and electrically and / or thermally isolates the electrode 108 from the faceplate 112.

[0022] The faceplate 112 features an opening 118 for allowing process gas to enter a process volume 120. The faceplate can be referred to as a showerhead. The faceplate 112 can be coupled to a power source 142 such as an RF (radio frequency) generator, a DC (direct current) power source, a pulsed DC power source, and a pulsed RF power source. Further, the power source 142 drives the faceplate 112 with one of a pulsed DC signal, a pulsed RF signal, and a ground (or any other constant voltage) signal to generate a plasma in the process volume 120.

[0023] The insulating member 111 is formed of a dielectric material and shields the electrode 108 and the insulating ring 110 from the process volume 120. For example, the insulating member 111 can be ceramic or metal oxide (e.g., aluminum oxide and / or aluminum nitride). The insulating member 111 forms a continuous annulus around the inner diameter of the process chamber 100 that encircles the process volume 120. Further, the insulating member 111 is formed of a single continuous material. Alternatively, the insulating member 111 can be formed of one or more materials to have one or more discrete segments. Further, the insulating member 111 is disposed above the liner 101 of the chamber body 102. For example, the insulating member 111 can be positioned between the liner 101 and the faceplate 112. Further, the distance between the insulating member 111 and the liner 101 is in a range from about 1 mm to about 20 mm. Alternatively, the distance between the insulating member 111 and the liner 101 can be less than 1 mm or greater than about 20 mm.

[0024] The insulating member 111 forms a barrier that isolates the electrode 108 and the insulating ring 110 from the process volume 120. The insulating member 111 protects the electrode 108 and the insulating ring 110 from process gases and thermal variations within the process volume 120. For example, during substrate processing, material deposition occurs on the insulating member 111 rather than on the electrode 108 and the insulating ring 110. Further, as deposition occurs on the electrode 108 and the insulating ring 110, or in the gap between the electrode 108 and the insulating ring 110, is mitigated by the presence of the insulating member 111, the overall likelihood of arcing within the process chamber 100 is reduced. In other words, the insulating member 111 reduces the thickness of the material deposited on the electrode 108 and the insulating ring 110 or in the gap between the electrode 108 and the insulating ring.

[0025] The faceplate 112 is either a conductive or non-conductive gas distributor. The faceplate 112 is made of conductive and / or non-conductive components. In a plasma processing chamber, the faceplate 112 can be powered, for example, by the power supply 142, or the faceplate 112 can be coupled to ground.

[0026] The insulating member 111 can contact the faceplate 112. Alternatively, the insulating member 111 can be separated from the faceplate 112, for example, by a ceramic spacer. In one embodiment, the insulating member 111 includes a radially extending lip 204 positioned between the insulating ring 110 and the faceplate 112. The lip 204 holds the insulating member 111 within the processing volume 120. In other embodiments, the insulating member 111 can be coupled to the faceplate 112 or another portion of the lid assembly 106, for example, by using fasteners. Alternatively, the insulating member 111 can be seated on another portion of the processing chamber 100 to hold the position of the insulating member 111 within the processing chamber 100.

[0027] The electrode 108 can be coupled to a power supply 128. The power supply 128 can drive the electrode 108 with a power signal. The power signal can include an RF source or a DC source. The power signal can be adjustable. For example, the magnitude of the voltage of the power signal and / or the sign of the voltage can be changed. Further, the voltage of the power signal can be positive or negative.

[0028] The electrode 122 is a portion of the substrate support 104. The electrode 122 is embedded within the substrate support 104 or coupled to a surface of the substrate support 104. The electrode 122 can be a plate, a perforated plate, a mesh, a screen, or any other distributed arrangement. Further, the electrode 122 is coupled to a power supply 136 by a conduit, such as a cable, disposed in a shaft 144 of the substrate support 104.

[0029] The power supply 136 includes an electronic sensor and an electronic controller, which can be a variable capacitor. The electronic sensor can be a voltage or current sensor and can be coupled to the electronic controller of the power supply 136 to provide further control of the plasma conditions in the processing volume 120. The power supply 136 drives the electrode 122 with one of a pulsed DC signal, a pulsed RF signal, and a ground voltage (or any other constant voltage) signal to generate a plasma in the processing volume 120. Further, the electrode 122 can be driven differently (e.g., opposite) from the faceplate 112 to generate a capacitively coupled plasma in the processing volume 120. For example, one of the faceplate 112 and the electrode 122 is driven by a pulsed RF signal and the other of the faceplate 112 and the electrode 122 is driven by a ground voltage signal. The power supplies 142 and 136 can be combined to form a power supply system. The power supply system can include the power supplies 142 and 136 and other power supplies.

[0030] The electrodes 124 can be biasing electrodes and / or electrostatic chucking electrodes, and the electrodes 124 are part of the substrate support 104. The electrodes 124 are embedded within or coupled to the substrate support 104. Further, the electrodes 124 are coupled to a power source 150. For example, the electrodes 124 are coupled to the power source 150 through a filter, which can be an impedance matching circuit. The power source 150 provides one or more of DC power, pulsed DC power, RF power, pulsed RF power.

[0031] In operation, the processing chamber 100 can provide real-time control of plasma conditions in the processing volume 120. The substrate 105 is positioned on the substrate support 104, and processing gas is flowed through the lid assembly 106 from the gas supply 160 according to a desired flow plan using the inlet 114. The gas exits the processing chamber 100 through the outlet 152. For example, a vacuum pump can be coupled to the outlet 152.

[0032] While Figure 1 Embodiments of the lid assembly 106 include the insulating ring 110, the electrode 108, and the insulating member 111, it is contemplated that the electrode 108 and the insulating ring 110 can be omitted.

[0033] Figure 2A is a schematic cross-sectional view of a portion 106 of a processing chamber 100 according to one or more embodiments. The insulating member 111 includes a surface 202, a surface 203, and a lip 204. The surface 203 faces the electrode 108 and the insulating ring 110, for example, the surface 203 is oriented radially outward. Further, the surface 203 does not contact the electrode 108 and the insulating ring 110, and a small uniform gap is formed between the surface 203 and the electrode 108 and the insulating ring 110. The surface 202 faces the processing volume 120, for example, the surface 202 is oriented radially inward. The gap between the surface 203 and the electrode 108 and the insulating ring 110 is less than about 1 mm. Further, the gap between the surface 203 and the electrode 108 and the insulating ring 110 can be less than about 0.5 mm. For example, the gap can be from about 0.1 mm to about 0.5 mm. In one embodiment, the gap between the surface 203 and the electrode 108 and the insulating ring 110 is omitted, and the surface 203 contacts the electrode 108 and the insulating ring 110. The gap between the surface 203 and the electrode 108 and the insulating ring 110 accommodates thermal expansion during processing. The size of the gap between the surface 203 and the electrode 108 and the insulating ring 110 mitigates contact of processing gas with the electrode 108 and the insulating ring 110, mitigating arcing that can occur due to material deposition on the electrode 108 and the insulating ring 110. In this way, the insulating member 111 acts as a deposition shield.

[0034] The lip 204 of the insulating member 111 is positioned between the insulating ring 110 and the faceplate 112. The lip 204 helps to retain the insulating member 111 within the processing volume 120 of the processing chamber 100. In one or more embodiments, the lip 204 can be omitted. In another example, the lip 204 can include one or more protrusions on an upper surface or a lower surface of the lip 204. The protrusions can index with corresponding recesses formed in an upper surface of the insulating ring and / or a lower surface of the faceplate 112.

[0035] Figure 2B is a top plan view of the insulating member 111. As Figure 2B explained above, the insulating member 111 includes a lip 204 positioned along a perimeter of the insulating member 111. The lip 204 is an annular member disposed in a plane. The lip 204 is used to secure the insulating member 111 within the processing chamber 100. For example, the lip 204 of the insulating member 111 is positioned between the insulating ring 110 (or, in embodiments where the insulating ring is omitted, the electrode 108) and the faceplate 112. The lip 204 extends radially outward from the cylinder 205 of the insulating member 111 at a distal end of the cylinder. The lip 204 is positioned at a right angle with respect to the cylinder (e.g., a sidewall of the cylinder or an axial centerline).

[0036] During substrate processing, material deposition occurs on the surface 202 of the insulating member 111, rather than on the electrode 108 and the insulating ring 110, and the gap between the electrode 108 and the insulating ring 110. As a result, the build-up of deposited material between the electrode 108 and the insulating ring 110 is reduced, thereby reducing the likelihood that an electric field across the gap between the electrode 108 and the insulating ring 110 will form an arc and discharge. The insulating member 111 protects the electrode 108 and the insulating ring 110 from process gases and thermal variations within the processing volume 120. Additionally, the surface 202 is smooth such that any material deposition that occurs on the surface 202 is uniform and can be removed during a cleaning cycle. The surface 202 can be smooth such that the build-up of deposited material is substantially uniform across the surface 202. The surface 202 has a roughness of at least about 8 Ra. Additionally, the surface 202 has a roughness of less than about 250 Ra. As a result, localized high electric fields between different points on the insulating member 111 do not occur. The surface 202 is continuous. Because any deposition occurs on the insulating member 111 rather than on the electrode 108 and the insulating ring 110, an increase in the corresponding electric field is mitigated, thereby reducing arcing within the processing chamber. Additionally, the surfaces 202 and 203 are at least substantially concentric with each other such that a distance between the surfaces 202 and 203 is substantially equal across the entire insulating member 111.

[0037] The height 210 of the insulating member 111 is at least equal to the combination of the height 214 of the electrode 108 and the height 212 of the insulating ring 110. Alternatively, the height 210 of the insulating member 111 can be greater than the combination of the heights 212 and 214. In such examples, the insulating member 111 at least partially overlaps the liner 101 such that the bottom surface of the electrode 108 and the bottom surface of the insulating member 111 are not coplanar. The height of the insulating member 111 is in a range from about 10 mm to about 120 mm. Alternatively, the height of the insulating member 111 is less than about 10 mm or greater than about 120 mm. Further, the heights 212 and 214 can be similar to one another, or one or more of the heights 212 and 214 can be greater than the other of the heights 212 and 214. Further, the width 220 of the insulating member 111 is in a range from about 1 mm to about 7 mm. Alternatively, the width of the insulating member 111 can be less than about 1 mm or greater than about 7 mm.

[0038] The insulating member 111 is positioned a distance (e.g., a vertical and / or horizontal distance) from the liner 101. For example, the distance can be less than about 1 mm. Alternatively, the distance can be greater than about 1 mm depending on the thickness and positioning of the liner 101.

[0039] The liner 101 includes a surface 230 and a surface 232. The surfaces 230 and 232 are concentric to one another. For example, the distance between the surfaces 230 and 232 can be substantially equal across the entire liner 101. Further, the width of the liner 101 (e.g., the distance between 230 and 232) can be greater than the width 220 of the insulating member 111.

[0040] Figure 3 is a schematic cross-sectional view of a processing chamber 300 according to one or more embodiments. The processing chamber 300 is configured similar to the processing chamber 100; however, while the lid assembly 106 includes the electrode 108 and the insulating ring 110, the lid assembly 306 includes the insulating ring 110, the electrode 108, and an insulating ring 310. Alternatively, the lid assembly 306 can include additional electrodes 108. Further, the lid assembly 306 can include one or more insulating rings 110, one or more insulating rings 310, and / or one or more electrodes 108.

[0041] The insulating ring 310 is a dielectric material, such as a ceramic or a metal oxide, for example, aluminum oxide and / or aluminum nitride, and the insulating ring 310 is in contact with the electrode 108 and electrically and thermally isolates the electrode 108 from the chamber body 102. Further, the insulating ring 310 is disposed between the electrode 108 and the chamber body 102.

[0042] Figure 3The insulating member 311 is configured similarly to the insulating member 111. The insulating member 311 is positioned between the insulating ring 110, the electrode 108, the insulating ring 310, and the processing volume 120. Figure 1 As described above, the insulating member 311 protects each of the insulating rings 110, 310 and the electrode 108, as well as the gap (at the opposing contact surfaces) between any of the insulating rings 110, 310 and the electrode 108 from thermal variations and process gases within the processing volume 120. For example, any material deposition occurs on the insulating member 311, rather than on the insulating rings 110 and 310 and the electrode 108 (or in the gap at the interface between the aforementioned components). Figure 3 In the example shown, the insulating member 311 spans at least the combined height of the insulating rings 110 , 310 and the electrode 108 .

[0043] Figure 4 is a schematic cross-sectional view of portion 306 of processing chamber 300, according to one or more embodiments. Insulating member 311 includes surface 402 and surface 403. Surface 403 faces electrode 108 and insulating rings 110 and 310. Similar to insulating member 111, insulating member 311 includes lip 204 extending radially outward from cylinder 205 of insulating member 111 at the distal end of cylinder 205. Furthermore, surface 403 does not contact electrode 108 and insulating rings 110 and 310, resulting in a small gap of less than approximately 1 mm between surface 403 and electrode 108 and insulating rings 110 and 310. In one embodiment, surface 403 contacts electrode 108 and insulating rings 110 and 310, and the gap is omitted. Omitting the gap further prevents process gas from contacting electrode 108 and insulating rings 110 and 310, thereby mitigating deposited material thereon. Additionally, surface 402 faces processing volume 120. During substrate processing, material deposition occurs on the surface 402 of the insulating member 311 rather than on the electrode 108 and the insulating rings 110 and 310, or any gaps therebetween. Thus, the insulating member 311 protects the electrode 108 and the insulating rings 110 and 310, as well as any corresponding gaps therebetween, from the effects of process gases and thermal variations within the processing volume 120. The height 410 of the insulating member 311 is at least equal to the combination of the height 414 of the electrode 108, the height 412 of the insulating ring 110, and the height 416 of the insulating ring 310. Alternatively, the height 410 of the insulating member 311 can be greater than the combination of the heights 412, 414, and 416. Furthermore, the heights 412, 414, and 416 can be similar, or one or more of the heights 412, 414, and 416 can be greater than another of the heights 412, 414, and 416.

[0044] A processing system having a lid assembly with an insulating member positioned between electrodes and an insulating ring of the lid assembly and a processing volume is disclosed. The disclosed processing system experiences reduced material build-up on the electrodes, the insulating ring, and the gap between the electrodes. As a result, the likelihood of arcing within the processing chamber of the processing system is reduced, reducing downtime of the processing system and increasing the throughput of the processing system. Furthermore, by reducing the thickness of the deposited material on the electrodes, the insulating ring, and the gap between the electrodes, the deposition capacity of the corresponding processing system is increased.

[0045] While the foregoing is directed to embodiments of the present disclosure, other and further embodiments of the disclosure can be devised without departing from the basic scope thereof.

Claims

1. A processing chamber comprising: Chamber body; a substrate support positioned in the chamber body; as well as a lid assembly positioned above the chamber body and defining a processing volume within the chamber body; the lid assembly comprising: panel; an electrode positioned between the face plate and the chamber body; and An insulating member, positioned radially inward from the electrode, is located between the electrode and the processing volume, and between the faceplate and the chamber body, wherein the insulating member does not contact the electrode.

2. The processing chamber of claim 1 , wherein the lid assembly further comprises: An insulating ring is positioned between the face plate and the chamber body.

3. The processing chamber of claim 2, wherein the insulating member is further positioned between the insulating ring and the processing volume.

4. The processing chamber of claim 1, further comprising a liner positioned on a surface of the chamber body, and wherein the insulating member is separated from the liner.

5. The processing chamber of claim 1, wherein the insulating member comprises ceramic.

6. The processing chamber of claim 1, wherein the insulating member comprises a continuous ring.

7. The processing chamber of claim 1, wherein the insulating member has a thickness in a range from about 1 mm to about 7 mm.

8. A cover assembly for a processing system, the cover assembly comprising: panel; an electrode disposed between the panel and a chamber body of the processing system; as well as An insulating member is positioned radially inward from the electrodes, wherein the insulating member does not contact the electrodes.

9. The cap assembly of claim 8, further comprising: An insulating ring is provided between the panel and the electrode.

10. The cap assembly of claim 9, wherein the insulating member is further positioned radially inward from the insulating ring and is separated from the electrode and the insulating ring by a gap. The cap assembly of claim 8 , wherein the insulating member comprises ceramic.

12. The cap assembly of claim 8, wherein the insulating member comprises a continuous ring. 13 . The cap assembly of claim 8 , wherein the insulating member has a thickness in a range of about 1 mm to about 7 mm.

14. A processing chamber comprising: Chamber body; a substrate support positioned in the chamber body, the substrate support comprising a first electrode; as well as a lid assembly positioned above the chamber body and defining a processing volume within the chamber body, the lid assembly comprising: panel; a second electrode positioned between the face plate and the chamber body; and An insulating member is positioned radially inward from the second electrode, between the second electrode and the processing volume, and between the faceplate and the chamber body, wherein the insulating member does not contact the second electrode.

15. The processing chamber of claim 14, wherein the lid assembly further comprises: An insulating ring is positioned between the face plate and the chamber body, and wherein the insulating member is further positioned between the insulating ring and the processing volume.

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