Shielding gas flow during wafer release in pvd chamber

Abstract

Methods, systems, and apparatus are provided for substrate processing by flowing a gas into a substrate processing chamber loading a substrate clamped to a chuck wherein the gas is introduced at a location above the substrate; and releasing the substrate while the gas is introduced.

Description

Technical Field

[0001] Embodiments of the present disclosure relate generally to substrate processing, and more particularly, to substrate dechucking. Background Art

[0002] During certain substrate processing (e.g., semiconductor die fabrication) in a processing chamber (e.g., a PVD chamber), tiny particles may contact the substrate, causing damage to the substrate. Therefore, such contact with the substrate is undesirable. As features on substrates become smaller, particle contamination tolerance becomes more stringent and has a greater impact on yield and productivity.

[0003] The inventors have observed that particles located between the substrate and the chuck can migrate to the upper surface of the substrate during the release process, which can lead to particle contamination beyond tolerance. Therefore, the inventors provide novel methods and apparatus to reduce or eliminate particle contamination during substrate processing. Summary of the invention

[0004] Methods, systems and apparatus for substrate processing are provided herein. In some embodiments, a method of substrate processing includes: flowing a gas into a substrate processing chamber that loads a substrate clamped to a chuck, wherein the gas is introduced at a position above the substrate; and releasing the substrate while the gas is flowing.

[0005] In some embodiments, an apparatus for substrate processing includes: a processing chamber having an inlet for directing a gas flow into the processing chamber and an outlet for exhausting a gas from the processing chamber; and a chuck disposed in the processing chamber and configured to support a substrate loaded in the processing chamber and to clamp and release the substrate, wherein the inlet is located above the chuck and the outlet is located below the chuck, wherein a gas flow path is defined from the inlet, around the chuck and to the outlet, and wherein the chuck is configured to release the substrate when the gas flows along the gas flow path.

[0006] In some embodiments, a system for processing a substrate includes an apparatus for substrate processing, comprising: a processing chamber having an inlet for directing a gas flow into the processing chamber and an outlet for exhausting the gas from the processing chamber; a chuck disposed in the processing chamber and configured to support a substrate loaded in the processing chamber and to clamp and release the substrate, wherein the inlet is located above the chuck and the outlet is located below the chuck, wherein a gas flow path is defined from the inlet, around the chuck and to the outlet, and wherein the chuck is configured to release the substrate when the gas flows along the gas flow path; a supply of gas connected to the inlet; and a vacuum source connected to the outlet.

[0007] Other and further embodiments of the present disclosure are described below. BRIEF DESCRIPTION OF THE DRAWINGS

[0008] The embodiments of the present disclosure, briefly summarized above and discussed in more detail below, can be understood by reference to the illustrative embodiments of the present disclosure depicted in the accompanying drawings. However, the drawings illustrate only typical embodiments of the present disclosure and are therefore not to be considered limiting of scope, as the present disclosure may admit to other equally effective embodiments.

[0009] Figure 1 is a schematic diagram of a substrate processing chamber according to an embodiment of the present disclosure.

[0010] Figure 2 According to the embodiments of the present disclosure Figure 1 Exploded diagram of a portion of .

[0011] Figure 3 is a flow chart illustrating a method according to an embodiment of the present disclosure.

[0012] To facilitate understanding, the same reference numerals are used as much as possible to represent common elements in 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 into other embodiments without further description. DETAILED DESCRIPTION

[0013] Embodiments of substrate processing methods and apparatus are provided herein that can reduce or eliminate particle migration from the lower surface of a substrate to the upper surface of a substrate during a release process. As a result, productivity and throughput can be improved.

[0014] Figure 1 is a schematic diagram of a substrate processing chamber 100 according to an embodiment of the present disclosure. In some embodiments, the substrate processing chamber 100 can be configured as a PVD processing chamber, as described in U.S. Pat. No. 11,037,768 B2, issued on June 15, 2021, and entitled METHODS AND APPARATUS FOR CONTROLLING ION FRACTION IN PHYSICAL VAPOR DEPOSITION PROCESSES. In some embodiments, and as Figure 1 As shown, the substrate processing chamber 100 may be loaded with a substrate support 102 to support a substrate 104. The substrate support 102 may include a chuck 103 to releasably clamp the substrate to the substrate support 102. In some embodiments, the chuck 103 may be an electrostatic chuck. Moreover, in some embodiments, and as Figure 1As shown, a process kit 106 (eg, including a shadow ring) can be disposed in the substrate processing chamber 100. The process kit 106 (and shadow ring) can surround the substrate 104 and the chuck 103.

[0015] The substrate processing chamber 100 may have an inlet 110 located above the substrate 104 and the chuck 103. The inlet 110 may be fluidly connected to a supply 120 of a gas that is compatible with the process and does not damage the substrate 104. In some embodiments, the substrate processing chamber 100 may have another inlet 114 located below the substrate 104 and the chuck 103. The inlet 114 may also be connected to a supply 122 of a gas that is compatible with the process. In some embodiments, the inlet 110 and the inlet 114 are connected to the same gas supply. In some embodiments, the gas compatible with the process includes argon and nitrogen. The substrate processing chamber 100 may have an outlet 112 connected to a vacuum pump 118 to exhaust the gas from the substrate processing chamber 100. The gas flow path 108 may be defined from the inlet 110 through the gap or space between the process kit 106 and the chuck 103 and to the outlet 112.

[0016] During substrate processing in the substrate processing chamber 100, the substrate 104 may be tightly clamped to the chuck 103 to prevent the substrate 104 from moving relative to the chuck 103. Once the substrate processing is completed, the substrate 104 may be transferred from the substrate processing chamber 100 for additional processing, such as in another substrate processing chamber. To transfer the substrate 104, the substrate 104 may undergo a release process to remove the clamping force on the substrate 104 so that the lift pins 116 located below the chuck 103 can be used to lift the substrate off the chuck 103.

[0017] In some embodiments, when the substrate 104 is released, the substrate 104 is not tightly clamped to the chuck 103, so that the particles 204 located between the lower surface 206 of the substrate 104 and the chuck 103 may migrate to the upper surface 208 of the substrate 104, such as Figure 2 In some embodiments, a gas may be introduced into the substrate processing chamber 100 at the inlet 110 at least during the release process to prevent or reduce such migration of particles 204. Figure 2As shown, when the gas from the inlet 110 flows in the substrate processing chamber 100, the gas may flow over the upper surface 208 of the substrate 104 and around the outer edge 210 of the substrate 104 and between the chuck 103 and the process kit toward the outlet 112. The flow rate of the gas introduced at the inlet 110 can be controlled and measured by a mass flow controller (not shown). In some embodiments, the pressure inside the substrate processing chamber 100 can be monitored, and the flow rate of the gas can be controlled based on the pressure. For example, in some embodiments, the flow of gas entering the substrate processing chamber 100 can be controlled to maintain a pressure of less than 150 mTorr. This pressure can limit the relative movement between the unclamped substrate 104 and the chuck 103.

[0018] Figure 3 300 is a flow chart of a substrate processing method 300 according to an embodiment of the present disclosure. At 301, some substrate processing (e.g., PVD deposition, etching, etc.) has been completed and the substrate 104 is clamped to the chuck 103. At 302, gas can be introduced into the substrate processing chamber 100 from the inlet 110 above the substrate 104. The gas flows downward along the gas flow path 108 to the outlet 112. At 303, a release process can be started and performed while continuing to introduce gas from the inlet 110. After the release process is completed, the gas flow from the inlet 110 can be turned off at 304. At 306, the method 300 can end and the released substrate 104 can then be transferred to another substrate processing chamber for additional processing.

[0019] While the foregoing is directed to embodiments of the present disclosure, other and further embodiments of the disclosure may be derived without departing from the basic scope thereof.

Claims

1. A method for processing a substrate, comprising: flowing a gas into a substrate processing chamber that loads a substrate clamped to a chuck, wherein the gas is introduced at a location above the substrate; and The substrate is released while the gas is flowing.

2. The method according to claim 1, further comprising: The flow of gas into the substrate processing chamber is stopped after releasing the substrate.

3. The method of claim 1, wherein the gas is exhausted from the substrate processing chamber at a location below the substrate. The method of claim 1 , wherein the substrate is released while the gas flows from above the substrate to below the substrate. 5 . The method of claim 1 , wherein the gas flows over an upper surface of the substrate and around an outer edge of the substrate. The method of claim 1 , wherein a flow rate of the gas is controlled based on a pressure in the substrate processing chamber. The method of claim 6 , wherein the flow rate of the gas is controlled to maintain the pressure less than 150 mTorr.

8. The method of claim 1, further comprising lifting the substrate off the chuck.

9. An apparatus for substrate processing, comprising: a processing chamber having an inlet for directing a flow of a gas into the processing chamber and an outlet for exhausting the gas from the processing chamber; a chuck disposed in the processing chamber and configured to support a substrate loaded in the processing chamber and to clamp and release the substrate, wherein the inlet is located above the chuck and the outlet is located below the chuck, wherein a gas flow path is defined from the inlet, around the chuck, and to the outlet; and A controller is configured to control the flow of the gas into the process chamber through the inlet to maintain a pressure inside the process chamber less than a predetermined value while releasing the substrate.

10. The apparatus of claim 9, wherein the processing chamber comprises another inlet located below the chuck and above the outlet.

11. The apparatus of claim 9, further comprising a process kit surrounding the chuck, wherein the gas flow path extends from the inlet, through a gap between the process kit and the chuck, and to the outlet.

12. The apparatus of claim 9, further comprising lift pins extending through the chuck, the lift pins configured to lift the substrate off the chuck.

13. A system for processing a substrate, comprising: An apparatus for substrate processing, comprising: a processing chamber having an inlet for directing a flow of a gas into the processing chamber and an outlet for exhausting the gas from the processing chamber; and a chuck disposed in the processing chamber and configured to support a substrate loaded in the processing chamber and to clamp and release the substrate, wherein the inlet is located above the chuck and the outlet is located below the chuck, wherein a gas flow path is defined from the inlet, around the chuck, and to the outlet; and A controller is configured to control the flow of the gas through the inlet into the processing chamber based on the pressure inside the processing chamber while releasing the substrate.

14. The system of claim 13, wherein the processing chamber includes another inlet located below the chuck and above the outlet.

15. The system of claim 13, further comprising a process kit surrounding the chuck, wherein the gas flow path extends from the inlet, through a gap between the process kit and the chuck, and to the outlet.

16. The system of claim 13, further comprising lift pins extending through the chuck, the lift pins configured to lift the substrate off the chuck.

17. The system of claim 13, wherein the gas is process compatible.

18. The system of claim 13, the controller comprising a flow controller configured to control a flow rate of the gas through the inlet and into the processing chamber.

19. The system of claim 18, wherein the flow controller is configured to control the flow rate to maintain the pressure inside the processing chamber below a predetermined value.

20. The system of claim 19, wherein the predetermined value is 150 mTorr.

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