Magnetic material shielding around the plasma chamber near the pedestal

Abstract

The plasma chamber includes a chamber body having a processing region therein, a liner disposed on the chamber body and surrounding the processing region, a substrate support disposed within the liner, a magnet assembly having a plurality of magnets disposed around the liner, and a magnetic material shield disposed around the liner, the magnetic material shield enclosing the processing region near the substrate support.

Description

Technical Field

[0001]

[0001] Embodiments of the present disclosure generally relate to semiconductor processing equipment, and more specifically, to a high-permeability magnetic material shield disposed around a plasma chamber that encloses a processing area near a substrate support disposed within the plasma chamber to adjust the plasma density profile within the processing area.

Background Art

[0002]

[0002] In low-pressure plasma processing of substrates such as plasma-enhanced chemical vapor deposition (PECVD), a permanent magnet assembly is used to control the plasma density profile and confine the plasma within the plasma chamber to increase the average plasma density, resulting in improved material deposition and deposition rate uniformity. Conventionally, the permanent magnet assembly is housed within a shield at a fixed position to shield the magnetic field generated within the chamber from sensitive equipment or adjacent chambers outside the chamber. However, since the magnetic field generated by the permanent magnet assembly disposed at a fixed position may not be properly adjusted, the plasma density profile may not be adjusted to further improve the material deposition and deposition rate uniformity.

[0003]

[0003] Therefore, there is a need for an improved system that prevents the magnetic field within the chamber from leaking outside the chamber to avoid interaction with adjacent chambers while allowing adjustment of the magnetic field profile in the processing area of the plasma chamber.

Summary of the Invention

[0004]

[0004] Embodiments of the present disclosure provide a plasma chamber. The plasma chamber includes a chamber body having a processing area therein, a liner disposed on the chamber body and surrounding the processing area, a substrate support disposed within the liner, a magnet assembly including a plurality of magnets disposed around the liner, and a magnetic material shield disposed around the liner that encloses the processing area near the substrate support.

[0005]

[0005] Embodiments of the present disclosure further provide a shield for use in a plasma chamber. The shield comprises a high-permeability magnetic material having a relative permeability of 50,000 or more. The high-permeability magnetic material is configured to be positioned around a liner located within the chamber body of the plasma chamber, and the high-permeability magnetic material is configured to enclose the processing area of ​​the plasma chamber.

[0006]

[0006] Embodiments of the present disclosure further provide a processing chamber. The processing chamber includes a lid assembly and a chamber body connected to the lid assembly by spacers, the spacers and the chamber body defining a processing area, a rotatable magnet assembly connected to the spacers outside the processing area, and a substrate support disposed and movable within the processing area. The substrate support is connected to an actuator configured to raise and lower the substrate support, a magnetic material shield is disposed around the spacers, and the magnetic material shield encloses the processing area near the substrate support.

[0007]

[0007] To enable a detailed understanding of the above-described features of the Disclosure, a more specific description of the Disclosure, which has been briefly summarized above, can be obtained by referring to embodiments. Some of these embodiments are illustrated in the accompanying drawings. However, it should be noted that the accompanying drawings only show typical embodiments of the Disclosure and should not be considered to limit the scope of the Disclosure, as the Disclosure may also permit other equally valid embodiments. [Brief explanation of the drawing]

[0008] [Figure 1A] This is a schematic cross-sectional view of an exemplary processing chamber according to one embodiment. [Figure 1B] This is a schematic cross-sectional view of an exemplary processing chamber according to one embodiment. [Figure 2A] This is an isometric view of the chamber body according to one embodiment. [Figure 2B] This is a top view of the chamber body according to one embodiment. [Modes for carrying out the invention]

[0009]

[0010] For ease of understanding, where possible, the same reference numerals were used to indicate identical elements common to the drawings. It is intended that elements and features of one embodiment can be advantageously incorporated into other embodiments without further description.

[0010]

[0011] Embodiments of this disclosure generally relate to semiconductor processing apparatus, and more specifically to a high-permeability magnetic material shield positioned around a plasma chamber to encapsulate a processing area near a substrate support placed within the plasma chamber. In low-pressure plasma processing of substrates, such as plasma chemical vapor deposition (PECVD), the plasma density profile is controlled using an assembly of permanent magnets placed on the chamber body, thereby confining the plasma within the plasma chamber to increase the average plasma density and consequently improve the uniformity of material deposition and deposition rate. Embodiments described herein provide a magnetic material shield positioned around a plasma chamber to encapsulate a processing area near a substrate support placed within the plasma chamber. The magnetic material shield adjusts the magnetic field profile, i.e., the plasma density profile, in the processing area to achieve improved uniformity of material deposition and deposition rate.

[0011]

[0012] Figures 1A and 1B are schematic cross-sectional views of an exemplary processing chamber 100 suitable for carrying out a deposition process.

[0012]

[0013] The processing chamber 100 includes a lid assembly 102, spacers 104 positioned on the chamber body 106, and a substrate support 108. The lid assembly 102 includes a faceplate 110 and a heat exchanger 112. The chamber body 106 is connected to the lid assembly 102 by the spacers 104.

[0013]

[0014] The lid assembly 102 is connected to a processing gas source 114. The processing gas source 114 contains a precursor gas for forming a film on a substrate W supported by a substrate support 108. The processing gas source 114 supplies the precursor gas to a plenum 116 located within the lid assembly 102. The lid assembly 102 includes one or more channels for guiding the precursor gas from the processing gas source 114 into the plenum 116. From the plenum 116, the precursor gas flows into the processing region 118. In some embodiments, another processing gas source (not shown) is fluidically connected to the processing region 118 via an inlet (not shown) that penetrates the spacer 104.

[0014]

[0015] The lid assembly 102 is also connected to an optional remote plasma source 120. The remote plasma source 120 is connected to a cleaning gas source 122 for supplying cleaning gas to a processing region 118 formed inside a spacer 104 between the lid assembly 102 and the substrate W. In one embodiment, the cleaning gas is supplied through a central conduit 124 formed axially through the lid assembly 102. In another embodiment, the cleaning gas is supplied through the same channel that guides the precursor gas. Exemplary cleaning gases include oxygen-containing gases such as oxygen and / or ozone, and fluorine-containing gases such as NF3, or combinations thereof.

[0015]

[0016] In addition to, or as a substitute for, the remote plasma source 120, the lid assembly 102 is further connected to a first high-frequency (RF) power supply 126. The first RF power supply 126 facilitates the maintenance or generation of plasma, such as plasma generated from a cleaning gas. In one embodiment, the remote plasma source 120 is omitted, and the cleaning gas is ionized in situ into plasma via the first RF power supply 126. The substrate support 108 is connected to a second RF power supply 128. The first RF power supply 126 may be a high-frequency RF power supply (e.g., about 13.56 MHz to about 120 MHz), and the second RF power supply 128 may be a low-frequency RF power supply (e.g., about 2 MHz to about 13.56 MHz). Note that other frequencies are also possible. In some implementations, the second RF power supply 128 is a mixed-frequency RF power supply that provides both high-frequency and low-frequency power. Film deposition is improved by utilizing a dual-frequency RF power supply, particularly for the second RF power supply 128. In one embodiment, the use of the second RF power supply 128 provides power at two frequencies. The first frequency, from approximately 2 MHz to approximately 13.56 MHz, improves seed injection into the deposited film, while the second frequency, from approximately 13.56 MHz to approximately 120 MHz, improves the ionization and deposition rate of the film.

[0016]

[0017] To generate or maintain plasma within the processing area 118, one or both of the first RF power supply 126 and the second RF power supply 128 are used. For example, the second RF power supply 128 may be used during the deposition process (either alone or in conjunction with the remote plasma source 120), and the first RF power supply 126 may be used during the cleaning process. In some deposition processes, the first RF power supply 126 is used together with the second RF power supply 128. During the deposition or etching process, one or both of the first RF power supply 126 and the second RF power supply 128 supply power from about 100 watts (W) to about 20,000 W into the processing space 118 to promote the ionization of the precursor gas. In some embodiments, at least one of the first RF power supply 126 and the second RF power supply 128 is pulsed.

[0017]

[0018] The substrate support 108 is connected to an actuator (not shown) that provides movement in the Z direction. The substrate support 108 is also connected to a flexible equipment cable 130, which allows for vertical movement of the substrate support 108 while maintaining other power and fluid connections, as well as communication with the second RF power supply 128. A spacer 104 is placed on the chamber body 106. A certain height of the spacer 104 allows for vertical movement of the substrate support 108 within the processing area 118. The height of the spacer 104 is between approximately 0.5 inches and approximately 20 inches. In one embodiment, the substrate support 108 is movable relative to the lid assembly 102 from a first distance 132A (shown in Figure 1A) to a second distance 132B (shown in Figure 1B). In one embodiment, the second distance 132B is approximately two-thirds of the first distance 132A. For example, the difference between the first distance 132A and the second distance is approximately 5 inches to approximately 6 inches.

[0018]

[0019] The processing chamber 100 further includes a substrate transport port 134. The substrate transport port 134 is selectively sealed by a door 136. The door 136 facilitates vacuum sealing of the processing area 118. The door 136 provides symmetrical RF application and / or plasma symmetry within the processing area 118. In one embodiment, the door 136 is formed of a material that facilitates the conductivity of RF power, such as stainless steel, aluminum, or an alloy thereof.

[0019]

[0020] The spacer 104 includes a liner 138 surrounding the processing area 118. In some embodiments, the spacer 104 and the liner 138 are made from a single piece of material. The liner 138 may be bonded to the spacer 104 (e.g., by diffusion bonding).

[0020]

[0021] The spacer 104 further includes a plurality of heating elements 140 that are embedded in or thermally connected to the body of the spacer 104. The heating elements 140 are used to maintain the temperature of the spacer 104 at approximately 80°C or higher. Each of the heating elements 140 may be a cartridge heater.

[0021]

[0022] The liner 138 includes an internal surface 142 exposed to the processing area 118. In some embodiments, the internal surface 142 may comprise one or more materials, including aluminum, titanium, or alloys thereof. The internal surface 142 of the liner 138 may be coated with one or more of aluminum, titanium, or alloys thereof. In some embodiments, the internal surface 142 may comprise one or more ceramic-containing materials. In one embodiment, the liner 138 extends from the lid assembly 102, beyond the substrate support 108, to a point adjacent to the bottom of the processing chamber 100. In such embodiments, the liner 138 may be separated from the bottom of the processing chamber 100 without making contact with it.

[0022]

[0023] The spacer 104 further includes a magnet assembly 146. The magnet assembly 146 may include a plurality of magnets 148 arranged around the liner 138. The magnets 148 are connected to actuators (not shown) and rotate around the longitudinal axis 150 of the processing chamber 100. The magnets 148 may be adapted to move perpendicularly (Z-direction) along the longitudinal axis 150. Each magnet 148 may be a permanent magnet of any shape, an electromagnet, or a combination thereof. In some embodiments, the plurality of magnets 148 are arranged in a circle around the spacer 104. The plurality of magnets 148 are arranged in two semicircles. Each magnet 148 in the first semicircle (indicated as 148a in Figures 2A and 2B) is oriented so that its north pole faces the substrate support 108 (substantially parallel to the longitudinal axis 150). Each of the second semicircular magnets 148 (indicated as 148b in Figures 2A and 2B) is oriented such that its south pole faces the substrate support 108 (substantially parallel to the longitudinal axis 150).

[0023]

[0024] The magnet assembly 146 assists in the confinement and / or regulation of the plasma in the processing region 118. During the deposition process, the magnet assembly 146 further forms a resonant cavity 170 within the processing region 118. The resonant cavity 170 provides a magnetic flux that extends the plasma sheath vertically downward (Z direction) toward the substrate W.

[0024]

[0025] The magnet assembly 146 provides a magnetic field in the X / Y plane and also in the Z direction. The magnet assembly 146 also enables adjustment of the plasma within the processing region 118 and / or the resonance cavity 170. Monitoring of the eddy currents in the plasma can define a measurement criterion for adjusting one or both of the position and the rotational speed of the magnet 148. Additionally or alternatively, measurement of a film pre-deposited on the substrate W can be performed, and the result can be used to vary the position and / or the rotational speed of the magnet 148. Thus, the resonance cavity 170 and the magnet assembly 146 provide better uniformity of the film on the substrate.

[0025]

[0026] Each magnet 148 is positioned within a cavity 152 formed within a sleeve 154 of the spacer 104. In one embodiment, the magnet 148 is positioned below the heating element 140. The material and thickness of the sleeve 154 make it possible to confine the magnetic field generated by the magnet 148 to the processing region 118 by controlling the magnetic permeability of the sleeve 154. Confining the magnetic field to the processing region 118 can mitigate the influence of the magnetic field on the processing region in the vicinity of an adjacent processing chamber and improve the uniformity of the process. A controller 156 connected to the processing chamber 100 and the magnet assembly 146 is configured to control the states of the processing chamber 100 and the magnet assembly 146 during processing.

[0026]

[0027] The processing chamber 100 further includes a cathode assembly 158 including a substrate support 108. The cathode assembly 158 is connected to an actuator 160 that moves the cathode assembly 158 in a direction perpendicular to the Z direction. The ability to adjust the position of the cathode assembly 158 for the deposition process can achieve optimal film quality.

[0027]

[0028] The cathode assembly 158 further includes an equipment interface 162. The equipment interface 162 provides connections for an RF power supply and other electrical and fluid connections. The equipment interface 162 is connected to the substrate support 108 via an equipment cable 130. Other connections include a power supply 164, a cooling source 166, and a gas supply unit 168. The power supply 164 can be used to power an electrostatic chuck 144, which is part of the substrate support 108. The power supply 164 may be a DC power supply. De-chucking is facilitated by a controller 156 that drains the electrostatic chuck 144. Furthermore, to facilitate operation within the processing chamber 100, the equipment cable 130 is optionally connected to a second RF power supply 128 via a matched network. In one embodiment, the equipment cable 130 facilitates the transmission of RF power during the PECVD process.

[0028]

[0029] Figures 2A and 2B are isometric and top views, respectively, of the chamber body 106. In the embodiments described herein, the spacer 104 includes a magnetic material shield (hereinafter simply referred to as "shield") 200 positioned around the liner 138 and enclosing a processing area 118 near the substrate support 108.

[0029]

[0030] The shield 200 is formed of a high-permeability magnetic material having a relative permeability of approximately 50,000 or more, for example, between approximately 80,000 and 100,000 (i.e., relative permeability to free space). The shield 200 not only attenuates the magnetic field strength near the liner 138 to prevent excessive deposition or etching on the walls of the chamber body 106, but also provides further adjustability of the magnetic field profile (and consequently, the plasma density profile) within the processing region 118. The magnetic field profile within the processing region 118 can be adjusted, for example, by the position of the shield 200 relative to the processing region 118, as well as by the material, size, and / or shape of the shield 200.

[0030]

[0031] Suitable high-permeability magnetic materials that provide high sensitivity for adjusting the magnetic field profile within the processing region 118 include one or more of nickel, iron, copper, chromium, molybdenum, or silicon. Examples of such high-permeability magnetic materials include nickel-molybdenum alloys (e.g., HyMu80®) and nickel-ion alloys (e.g., MuMETAL®).

[0031]

[0032] The shield 200 may be cylindrical in shape and extend in the Z direction. In some embodiments, the shield 200 has a non-cylindrical cross-section, such as a polygon. The shield 200 may have a length in the Z direction between about 2 inches and about 10 inches. The shield 200 extends in the Z direction from the magnet assembly 146, which includes a plurality of magnets 148. Across a distance It may be positioned in a fixed location. The position of the shield 200 may be fixed or movable to allow for further adjustment of the plasma density profile within the processing area.

[0032]

[0033] The shield 200 may be coated with a non-reactive material such as aluminum, aluminum oxide, silicon dioxide, or polytetrafluoroethylene (PTFE) to prevent contamination by precursor gas or washing gas in the processing chamber 100.

[0033]

[0034] Embodiments described herein describe a magnetic material shield positioned around the chamber body and enclosing the processing area near a substrate support located within the chamber body. The magnetic material shield reduces the magnetic field near the inner walls of the chamber body, preventing excessive deposition and etching on the inner walls. The magnetic material shield also attenuates magnetic fields penetrating the outside of the chamber body, preventing interaction with any adjacent chambers and ensuring the safety of nearby users. The ability to reposition the magnetic material shield provides further adjustability of the magnetic field profile and plasma density profile within the processing area.

[0034]

[0035] While the above description applies to embodiments of the present disclosure, other embodiments and further embodiments of the present disclosure may be devised without departing from the basic scope of the present disclosure. The scope of the present disclosure is determined by the following claims.

Claims

1. Chamber body having a processing area inside, A liner is placed on the chamber body and surrounds the processing area. A substrate support disposed within the liner, A magnet assembly comprising a plurality of magnets arranged around the liner, and A magnetic material shield disposed around the liner, the magnetic material shield enclosing the processing area near the substrate support. Equipped with, The magnetic material shield has a cylindrical shape that extends in the direction of the length of the chamber body, A plasma chamber in which the magnetic material shield is positioned at a distance from the magnet assembly in the direction of the length of the chamber body.

2. A chamber body having a processing area inside, A liner is placed on the chamber body and surrounds the processing area. A substrate support disposed within the liner, A magnet assembly comprising a plurality of magnets arranged around the liner, and A magnetic material shield disposed around the liner, the magnetic material shield enclosing the processing area near the substrate support. Equipped with, A plasma chamber in which the magnetic material shield includes a high-permeability magnetic material having a relative permeability of 50,000 or more.

3. The plasma chamber according to claim 2, wherein the high-permeability magnetic material includes a nickel-molybdenum alloy.

4. A chamber body having a processing area inside, A liner is placed on the chamber body and surrounds the processing area. A substrate support disposed within the liner, A magnet assembly comprising a plurality of magnets arranged around the liner, A magnetic material shield disposed around the liner, the magnetic material shield enclosing the processing region near the substrate support, and A sleeve formed around the magnet assembly, which confines the magnetic field generated by the plurality of magnets to the processing area. A plasma chamber equipped with a plasma chamber.

5. The plasma chamber according to claim 1, wherein the magnetic material shield has lengths between 5.08 cm and 25.4 cm (2 inches and 10 inches) in the direction of the length of the chamber body.

6. A shield for use in a plasma chamber, Equipped with a high-permeability magnetic material having a relative permeability of 50,000 or more, The aforementioned high-permeability magnetic material is configured to be positioned around a liner located within the chamber body of the plasma chamber. The high-permeability magnetic material is configured to enclose the processing area of ​​the plasma chamber. The aforementioned high-permeability magnetic material is formed into a cylindrical shape and extends in the direction of the length of the chamber body, A shield in which the high-permeability magnetic material is positioned at a distance from the magnet assembly arranged around the liner in the longitudinal direction of the chamber body.

7. The shield according to claim 6, wherein the high permeability magnetic material includes a nickel-molybdenum alloy.

8. The shield according to claim 6, wherein the high-permeability magnetic material is molded to have lengths between 5.08 cm and 25.4 cm (2 inches and 10 inches) in the direction of the length of the chamber body.

9. Lid assembly, A chamber body connected to the lid assembly by a spacer, wherein the spacer and the chamber body define a processing area, A rotatable magnet assembly connected to the spacer outside the processing area, A substrate support arranged within the processing area and movable, the substrate support connected to an actuator configured to raise and lower the substrate support, and A magnetic material shield disposed around the spacer, the magnetic material shield enclosing the processing area near the substrate support. A processing chamber equipped with a processing chamber.

10. The processing chamber according to claim 9, wherein the lid assembly comprises a heat exchanger.

11. The processing chamber according to claim 9, wherein the spacer comprises a plurality of heating elements.

12. The processing chamber according to claim 9, wherein the spacer comprises a liner surrounding the processing area.

13. The processing chamber according to claim 9, wherein the rotatable magnet assembly comprises a plurality of magnets.

14. The processing chamber according to claim 9, wherein the magnetic material shield includes a high-permeability magnetic material having a relative permeability of 50,000 or more.

15. The processing chamber according to claim 9, wherein the magnetic material shield has lengths between 5.08 cm and 25.4 cm (2 inches and 10 inches) in the direction of the length of the chamber body.

16. The processing chamber according to claim 9, wherein the magnetic material shield is positioned at a distance from the rotatable magnet assembly in the direction of the length of the chamber body.

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