Arc-reduced physical vapor deposition (PVD) chamber

Abstract

Embodiments of a process chamber are provided herein. In some embodiments, the process chamber includes a chamber body having an interior volume, a substrate support disposed in the interior volume, a target disposed in the interior volume facing the substrate support, a process shield disposed in the interior volume and having an upper portion surrounding the target and a lower portion surrounding the substrate support, the upper portion having an inner diameter larger than an outer diameter of the target to define a gap between the process shield and the target, and a gas inlet for supplying gas to the interior volume through the gap or across a front opening of the gap to substantially prevent particles from the interior volume from entering the gap during use. [Selected Figure] Figure 1

Description

[Technical Field]

[0001] FIELD OF THE DISCLOSURE Embodiments of the present disclosure relate generally to semiconductor processing techniques, and more particularly to techniques for physical vapor deposition of materials onto a substrate. [Background technology]

[0002] Sputtering, also known as physical vapor deposition (PVD), is a method for forming features in integrated circuits. Sputtering deposits layers of material onto a substrate. A source material, such as a target, is bombarded with ions, ejecting material from the target. The material is then deposited on the substrate. The inventors observed that during the deposition process, material or contaminants can cause outgassing from the substrate. The outgassing from the substrate can reach the target and cause arcing. Summary of the Invention [Problem to be solved by the invention]

[0003] Therefore, the inventors have provided an improved PVD processing chamber and method of use thereof. [Means for solving the problem]

[0004]

[0006] Embodiments of a physical vapor deposition (PVD) process chamber are provided herein. In some embodiments, the process chamber includes a chamber body having an interior volume, a substrate support disposed in the interior volume, a target disposed within the interior volume facing the substrate support, a process shield disposed in the interior volume and having an upper portion surrounding the target and a lower portion surrounding the substrate support, the upper portion having an inner diameter larger than an outer diameter of the target to define a gap between the process shield and the target, and a gas inlet for supplying gas to the interior volume through the gap or across a front opening of the gap to substantially prevent particles from the interior volume from entering the gap during use.

[0005] In some embodiments, a physical vapor deposition (PVD) process chamber includes a target disposed within an interior volume of the PVD process chamber near a lid of the PVD process chamber; a substrate support disposed in the PVD process chamber facing the target; a process shield disposed away from the target to surround the target and define a gap between the process shield and the target; one or more gas inlets disposed between the substrate support and the lid to supply gas to the interior volume through the gap or across a front opening of the gap to substantially prevent particles from within the process chamber from entering the gap during use; and a pump in fluid communication with the process chamber to remove gas from the process chamber during use.

[0006] In some embodiments, a method for processing a substrate includes performing a physical vapor deposition (PVD) process on a substrate within an interior volume of a process chamber, wherein a process shield is positioned around a target in the interior volume such that an outer sidewall of the target and an interior surface of the process shield define a gap, and injecting gas into the process chamber via a first gas inlet, through the gap or across a front opening of the gap, to substantially prevent particles from the interior volume from entering the gap.

[0007] Other and further embodiments of the present disclosure are described below.

[0008] Embodiments of the present disclosure, briefly summarized above and discussed in more detail below, can be understood by reference to exemplary embodiments of the present disclosure, which are depicted in the accompanying drawings, which illustrate only some embodiments of the present disclosure and, therefore, should not be considered limiting in scope, as the present disclosure may admit of other, equally effective, embodiments. [Brief explanation of the drawings]

[0009] [Figure 1]FIG. 1 is a schematic diagram of a process chamber in accordance with at least some embodiments of the present disclosure. [Figure 2] FIG. 1 is a schematic diagram of a process chamber in accordance with at least some embodiments of the present disclosure. [Figure 3] 1 is a flow diagram of a method for processing a substrate in accordance with at least some embodiments of the present disclosure. DETAILED DESCRIPTION OF THE INVENTION

[0010] For ease of understanding, the same reference numerals have been used, where possible, to designate identical elements common to the figures. The figures are not drawn to scale and may be simplified for clarity. Elements and features of one embodiment may be beneficially incorporated in other embodiments without further elaboration.

[0011] Embodiments of an improved process chamber and an improved method for processing a substrate are provided herein. The embodiments disclosed above can be performed in a suitably configured physical vapor deposition (PVD) process chamber. For example, Figures 1 and 2 show schematic diagrams of a process chamber suitable for performing the methods described herein in accordance with some embodiments of the present disclosure. The particular configuration of the process chamber is exemplary, and process chambers having other configurations may also be modified in accordance with the teachings provided herein. also benefit from Examples of process chambers suitable for modification according to the teachings disclosed herein include any of the ENDURA® line of PVD processing chambers commercially available from Applied Materials, Inc. of Santa Clara, Calif. Applied Materials, Inc. or others Company Other processing chambers from the product line can also benefit from the teachings disclosed herein.

[0012] As shown in FIG. 1 , a process chamber 100 for performing a PVD process includes a chamber body 152. The chamber body 152 generally includes a top wall 102 (or lid), a bottom wall 104, and a sidewall 106 connecting the top wall 102 to the bottom wall 104. The top wall 102, the bottom wall 104, and the sidewall 106 define an interior volume 122. In some embodiments, the chamber body 152 includes an adapter 112 extending radially inward from the sidewall 106. The adapter 112 can be part of the sidewall 106 or can be a separate component. In some embodiments, the adapter 112 can be part of a process shield (described below). The top wall 102 can be coupled to the sidewall 106 via the adapter 112. In some embodiments, a seal ring 114 can be disposed between the adapter 112 and the top wall 102 to prevent fluid from passing between them (e.g., during processing at vacuum pressure in the interior volume 122). The top wall 102 is generally removable from the side wall 106, for example, to facilitate maintenance or replacement of the target 110, as discussed below. The chamber body 152 can be grounded via a bond to ground 154. The top wall 102 can be electrically floating or grounded.

[0013] An exhaust port 120 is disposed adjacent the bottom wall 104 of the chamber body 152. As shown in FIG. 1 , the exhaust port 120 is disposed in an opening in the bottom wall 104. In some embodiments, a pump 118 is coupled to the exhaust port 120. The pump 118 is configured to regulate the pressure within the chamber body 152, such as by maintaining a vacuum. In some embodiments, the pump 118 is configured to evacuate gases introduced into the interior volume 122 during the deposition process. In some embodiments, the pump 118 is configured to evacuate gases formed during the deposition process.

[0014] A substrate support 124 is disposed in the interior volume 122. In some embodiments, the substrate support 124 includes a shaft 126 and a pedestal 128. The shaft 126 can include conduits that supply, for example, fluids, coolants, power, etc., to the pedestal 128. The pedestal 128 has an upper surface 134 configured to receive a substrate 130 (such as a 200 mm, 300 mm, or other form factor substrate) for processing. The substrate support 124 is configured to support the substrate 130 such that the center of the substrate 130 is aligned with a central axis of the process chamber 100 (or of the processing volume 156, discussed below). The substrate support 124 is coupled to an RF bias power supply 116. In some embodiments, the RF bias power supply 116 is configured to induce an AC or DC bias on the substrate 130.

[0015] The target 110 is disposed within the interior volume 122 of the chamber body 152. The target 110 is positioned opposite the substrate support 124. For example, the target 110 may be coupled to the top wall 102. The process chamber 100 includes an RF power supply 108 and an associated magnetron coupled to the target 110. The RF power supply 108 is configured to supply RF energy to the target 110. The target 110 includes a source material to be deposited on the substrate 130 during sputtering. In some embodiments, the source material can be a metal, a metal oxide, an alloy, or the like. In some embodiments, the target 110 can include a backing plate including a conductive material, such that the RF power supply 108 can be coupled to the target 110 through the backing plate.

[0016] A process shield 138 having an upper portion 140 and a lower portion 142 is disposed in the interior volume 122. In some embodiments, the process shield 138 has a cylindrical body. In some embodiments, the process shield 138 comprises a single-piece metal body. In some embodiments, the process shield 138 comprises a single-piece body including the adapter 112. The lower portion 142 surrounds the substrate support 124. In some embodiments, the upper portion 140 is positioned around and spaced apart from the target 110 to form a gap 150 (e.g., an annular gap in a circular target / shield configuration) between the upper portion 140 of the process shield 138 and the target 110. The gap 150 extends from the inner surface of the upper portion 140 of the process shield 138 to the outer sidewall of the target 110. The outer edge of the target 110 and the inner surface of the upper portion 140 define a front opening of the gap 150. The process shield 138 , the target 110 , and the substrate support define a processing volume 156 within the interior volume 122 .

[0017] As described in more detail below, a gas inlet is positioned near the target 110 to supply process gas to the interior volume 122 at a location adjacent to the target 110. In some embodiments, as shown in FIG. 1 , the gas inlet is a gas inlet 146 positioned through the top surface of the process shield 138. A conduit 164 is positioned through the process shield 138 and terminates at the gas inlet 146. The conduit 164 is coupled to a first gas source 170 to supply a gas, e.g., a process gas, to the processing volume 156 through the gas inlet 146. The gas inlet 146 is positioned in a location that provides a gas flow path 144 through the gap 150 to advantageously prevent or substantially prevent particles from within the process chamber from flowing into the gap 150. In some embodiments, the gas inlet 146 can be positioned on the top surface of the process shield 138, as shown. In some embodiments, the gas inlet 146 may be disposed on a radially inward surface adjacent the top surface of the process shield 138 such that gas supplied to the interior volume 122 flows through the gap 150. In some embodiments, the gas passage 144 passes from the space between the top wall 102 and the process shield 138 through the gap 150 into the processing volume 156 via the gas inlet 146. The gas inlet 146 is configured to flow the process gas into the interior volume 122 such that the process gas moves gases within the interior volume away from the gap 150 between the process shield 138 and the target 110. In some embodiments, the process gas is reactive, including, for example, nitrogen (N), oxygen (O), etc. In some embodiments, the process gas is inert, including, for example, argon (Ar), helium (He), krypton (Kr), xenon (Xe), etc. In some embodiments, the process gas is a mixture of a reactive gas and an inert gas, such as any combination of reactive and inert gases disclosed above. The directing flow path 136 passes from the processing volume 156 downwardly through a gap between the lower portion 142 of the process shield 138 and the substrate support 124 toward the bottom wall 104 (e.g., toward the exhaust port 120). The gas inlet 146 can include one or more gas inlets.In some embodiments, the gas inlet 146 is configured to uniformly distribute gas from a source external to the process chamber 100 into the processing volume 156 .

[0018] 2, the gas inlet is a gas inlet 202 disposed in a sidewall of the process shield 138. A conduit 212 is disposed through the process shield 138 and terminates at the gas inlet 202 in the process shield 138. The conduit 212 is coupled to a first gas source 170 to supply a gas, e.g., a process gas, to the gas inlet 202. 202 The gas is fed to the processing volume 156 through a gas inlet. 202 is advantageously positioned to provide a gas flow path 204 across the opening of the gap 150 (e.g., to form a gas curtain across the front of the gap 150) to prevent or substantially prevent particles from within the process chamber from flowing into the gap 150. The process gas can be any of the process gases described above with respect to FIG. 1. The gas inlet 202 can include one or more gas inlets. In some embodiments, the gas inlet 202 is configured to uniformly distribute gas from a source external to the process chamber 100 into the processing volume 156.

[0019] Either or both of the gas inlet 146 or the gas inlet 202 can be a single gas inlet or multiple gas inlets arranged to supply a substantially uniform flow of gas through the gap 150 into the processing volume 156 or across the front opening of the gap 150 to prevent or substantially prevent particles from flowing into the gap 150. For example, the first gas source 170 can be coupled to one or more inlets arranged in the process shield 138 to supply gas to an internal channel or plenum arranged within the process shield 138. For example, multiple gas inlets configured as the gas inlet 146 or the gas inlet 202 can be arranged in the process shield 138 to couple the internal channel or plenum to the processing volume 156 via the gas inlets. In some embodiments, the multiple gas inlets can be equidistantly and angularly spaced from one another.

[0020] During use, a source material, such as the target 110, is bombarded by ions from the plasma, ejecting material from the target 110. For example, a process gas can be supplied to the processing volume, and sufficient power can be supplied to the target 110 to excite the process gas into a plasma. The ejected material is then deposited on the substrate 130. During the deposition process, material or contaminants can be liberated from the substrate toward the target 110, for example, via outgassing, and are generally represented by arrows 132. The material or contaminants can condense on surfaces facing the processing volume 156, including in the area between the target 110 and the process shield 138. Condensation in the area between the target 110 and the process shield 138 can cause arcing during processing.

[0021] Gas inlets 146, 202 located near the target 110 advantageously reduce or prevent material or contaminants (e.g., arrow 132) from reaching the target 110 or the region between the target and the process shield 138, thereby reducing or preventing arcing. Gas inlets 146, 202 located near the target 110 advantageously reduce or prevent material or contaminants from redepositing on the target 110 or an upper portion of the process shield 138. A pump 118 is in fluid communication with the process chamber 100 via an exhaust port 120 for removing gases from the process chamber 100 during use.

[0022] In some embodiments, the second gas inlet 148 is disposed between the process shield 138 and the bottom wall 104, including within the bottom wall 104. For example, the second gas inlet 148 can be disposed outside and below the processing volume 156 or below the pedestal 128. A conduit 168 is disposed through the sidewall 106 and terminates at the second gas inlet 148. The conduit 168 is coupled to a second gas source 180 to supply gas to the processing volume 156 through the gas inlet 148. The second gas inlet 148 can supply additional inert, reactive, or a mixture of inert and reactive process gases to the interior volume 122. The additional process gas may be the same as the process gas supplied by the gas inlets 146, 202. In some embodiments, the second gas inlet 148 is configured to direct gas within the interior volume 122 toward the exhaust outlet 120. For example, the second gas inlet 148 can direct gas from the guide channel 136 towards the exhaust port 120. In some embodiments, the second gas inlet 148 is positioned on a side of the chamber body 152 opposite the pump 118.

[0023] In some embodiments, the process chamber 100 can include a gas inlet 146 and a gas inlet 202. In some embodiments, parameters of the process chamber 100 can be adjusted to promote a downward gas flow within the chamber body 152. The parameters include process gas flow rates, pressures, etc.

[0024] 3 is a flow diagram of a method 300 for processing a substrate in accordance with at least some embodiments of the present disclosure. At 302, the method 300 for processing a substrate includes performing a physical vapor deposition (PVD) process on the substrate within an interior volume of a process chamber, wherein a process shield is disposed around a target in the interior volume such that an outer sidewall of the target and an interior surface of the process shield define a gap. In some embodiments, the process chamber 100 described above can be used to perform the method 300. In some embodiments, any suitable PVD process chamber can be used.

[0025] At 304, the method 300 includes injecting a gas into the process chamber via a first gas inlet, through the gap or across a front opening of the gap, to substantially prevent particles from the interior volume from entering the gap. The gas can be reactive or inert. In some embodiments, the method 300 includes using a pump to remove the gas from the process chamber. In some embodiments, the method 300 includes injecting an additional gas near a lower portion of the process chamber via a second gas inlet to direct gas flow within the process chamber toward the pump. The gas injected by the second gas inlet can be reactive or inert.

[0026] While the forgoing is directed to embodiments of the present disclosure, other and further embodiments of the present disclosure may be devised without departing from the basic scope thereof.

Claims

1. a chamber body having an interior volume; a substrate support disposed in the interior volume; a process shield disposed in the interior volume, the process shield having an upper portion configured to surround a target and a lower portion surrounding the substrate support, the upper portion having an inner diameter larger than an outer diameter of the target to define a gap between the process shield and the target, the gap having an open first end and a closed second end opposite the first end; a gas inlet for supplying gas to the interior volume through the gap or across a front opening of the gap, the gas inlet being positioned on an upper surface of the process shield vertically above the front opening of the gap and adjacent the closed second end of the gap, or positioned below the target and configured to direct gas horizontally inward across the front opening of the gap adjacent to the target, the gas inlet configured to substantially prevent particles from the interior volume from entering the gap during use; a process chamber including:

2. The process chamber of claim 1 , further comprising an exhaust port disposed adjacent a bottom wall of the chamber body.

3. 2. The process chamber of claim 1, wherein the gas inlet is positioned below the target and extends horizontally through a sidewall of the process shield to deliver the gas across a front opening of the gap.

4. The process chamber of claim 3 further comprising a second gas inlet disposed between the process shield and a bottom wall.

5. 5. The process chamber of claim 4, wherein the gas inlet is coupled to a first gas source and the second gas inlet is coupled to a second gas source that is fluidly independent from the first gas source.

6. The process chamber of claim 4 , wherein the second gas inlet is configured to direct gas within the interior volume toward an exhaust outlet.

7. The process chamber of claim 4 , wherein the second gas inlet is located on a side of the substrate support opposite a pump.

8. The process chamber of any one of claims 1 to 7, wherein the gas inlet is located in the process shield.

9. The process chamber of any one of claims 1 to 7, wherein the gas inlet is configured to flow the gas through a gap located between the process shield and the target.

10. The process chamber of any one of claims 1 to 7, wherein the process shield comprises a single-piece metal body.

11. The process chamber of any one of claims 1 to 7, wherein the process shield comprises a cylindrical body.

12. 1. A method of processing a substrate, comprising: performing a physical vapor deposition (PVD) process on a substrate within an interior volume of a process chamber, the process shield being positioned around the target in the interior volume such that an outer sidewall of the target and an interior surface of the process shield define a gap having an open first end and a closed second end opposite the first end; injecting gas into the process chamber through the gap via a first gas inlet located on the top surface of the process shield vertically above the gap front opening and proximate the closed second end, or across the gap front opening via a first gas inlet located below the target and configured to direct gas horizontally inward across the gap front opening proximate the target; Including, The method, wherein the first gas inlet is configured to substantially prevent particles from the interior volume from entering the gap.

13. The method of claim 12 further comprising using a pump to remove the gas from the process chamber.

14. 14. The method of claim 13, further comprising additionally injecting the gas near a lower portion of the process chamber via a second gas inlet to direct the gas within the process chamber toward the pump.

15. The method of any one of claims 12 to 14, wherein the first gas inlet is configured to flow the gas through a gap disposed between the process shield and the target.

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