JP-2026514448-A - Novel Inductively Coupled Plasma Apparatus with Faraday Shield

Abstract

This is an antenna assembly. The antenna assembly may include an antenna having a loop structure and a dielectric window adjacent to the antenna. The antenna assembly may also include a Faraday shield assembly positioned between the antenna and the dielectric window, the Faraday shield assembly being positioned at least partially around the antenna. The Faraday shield assembly may include a plurality of metal sections electrically insulated from each other, the plurality of metal sections being positioned in a plurality of shield pairs. Thus, a first metal section and a second metal section of a given shield pair may be positioned opposite each other and electrically connected to each other. [Selection Diagram] Figure 1

Inventors

• アレクサンドロヴィッチ， ベンジャミン
• クルンチ， ピーター エフ．
• マレル， デーヴィッド
• カルキンス， アダム

Assignees

• アプライド マテリアルズ インコーポレイテッド

Dates

Publication Date

20260511

Application Date

20240514

Priority Date

20230517

Claims (19)

1. An antenna assembly, An antenna having a loop structure, A dielectric window adjacent to the aforementioned antenna, A Faraday shield assembly disposed between the antenna and the dielectric window, comprising a Faraday shield assembly at least partially disposed around the antenna, The Faraday shield assembly comprises a plurality of metal sections electrically insulated from each other, the plurality of metal sections arranged in a plurality of shield pairs, the first metal section and the second metal section of a given shield pair being arranged opposite each other and electrically connected to each other, the antenna assembly.
2. The antenna has a first end and a second end positioned adjacent to the first end. The loop structure has a first leg portion extending from the first end parallel to the antenna axis, a second leg portion extending from the second end parallel to the antenna axis, and an intermediate section joining the first leg portion and the second leg portion. The antenna assembly according to claim 1, wherein the first metal section is arranged around the first leg and the second metal section is arranged around the second leg.
3. The antenna assembly according to claim 2, wherein the dielectric window is configured as a dielectric cylinder surrounding the antenna and has a cylinder axis extending parallel to the antenna axis.
4. The antenna assembly according to claim 1, wherein the plurality of metal sections are arranged coaxially around the antenna.
5. The antenna assembly according to claim 4, wherein the plurality of metal sections are arranged equidistant from the antenna along the length of the antenna.
6. The antenna assembly according to claim 4, wherein the plurality of metal sections have a C-shaped cross-section.
7. The antenna assembly according to claim 6, wherein the loop structure has a first leg portion and a second leg portion, and the open portion of the first metal section of the given shield pair faces the open portion of the second metal section of the given shield pair.
8. The antenna assembly according to claim 2, wherein the Faraday shield assembly is positioned around a first region of the antenna toward the first and second ends, and the Faraday shield assembly is not positioned around a second region of the antenna relatively close to the intermediate section.
9. It is a plasma source, A plasma chamber surrounds a plasma space containing plasma inside, An antenna assembly disposed within or adjacent to the plasma chamber, An antenna with a loop structure, The antenna assembly comprises a dielectric window adjacent to the antenna, and a Faraday shield assembly disposed between the antenna and the dielectric window, the Faraday shield assembly being at least partially disposed around the antenna, The Faraday shield assembly comprises a plurality of metal sections electrically insulated from each other, the plurality of metal sections arranged in a plurality of shield pairs, the first metal section and the second metal section of a given shield pair being arranged opposite each other and electrically connected to each other, in a plasma source.
10. The antenna has a first end and a second end positioned adjacent to the first end. The loop structure has a first leg portion extending from the first end parallel to the antenna axis, a second leg portion extending from the second end parallel to the antenna axis, and an intermediate section joining the first leg portion and the second leg portion. The plasma source according to claim 9, wherein the first metal section is arranged around the first leg and the second metal section is arranged around the second leg.
11. The plasma source according to claim 10, wherein the dielectric window is configured as a dielectric cylinder surrounding the antenna and has a cylinder axis extending parallel to the antenna axis.
12. The plasma source according to claim 9, wherein the plurality of metal sections are arranged coaxially around the antenna.
13. The plasma source according to claim 12, wherein the plurality of metal sections are arranged equidistant from the antenna along the length of the antenna.
14. The plasma source according to claim 12, wherein the plurality of metal sections have a C-shaped cross-section.
15. The plasma source according to claim 14, wherein the loop structure has a first leg portion and a second leg portion, and the open portion of the first metal section of the given shield pair faces the open portion of the second metal section of the given shield pair.
16. The plasma source according to claim 10, wherein the Faraday shield assembly is positioned around a first region of the antenna toward the first and second ends, and the Faraday shield assembly is not positioned around a second region of the antenna relatively close to the intermediate section.
17. Processing apparatus, A plasma chamber surrounds a plasma space containing plasma inside, An extraction plate positioned on the side of the plasma chamber, An antenna assembly disposed within or adjacent to the plasma chamber, An antenna with a loop structure, An antenna assembly comprising a dielectric window adjacent to the antenna, and a Faraday shield assembly disposed between the antenna and the dielectric window and at least partially disposed around the antenna, comprising a plurality of metal sections electrically insulated from each other, wherein the plurality of metal sections are arranged in a plurality of shield pairs, A processing apparatus comprising an RF assembly connected to a first end and a second end of the antenna to provide a balanced RF voltage signal.
18. The processing apparatus according to claim 17, wherein the RF assembly is configured to supply a first RF signal having a first maximum amplitude and a first phase to the first end, and further configured to supply a second RF signal having a second phase opposite to the first maximum amplitude and the first phase to the second end.
19. The processing apparatus according to claim 17, wherein the RF assembly includes an RF balance network.

Description

Cross-reference of related applications [0001] This application claims the benefit of priority of U.S. Patent Application No. 18/198,682, filed on 17 May 2023, which is incorporated herein by reference in its entirety. [0002] This disclosure relates, in general, to processing equipment, and more specifically, to an antenna assembly for generating inductively coupled plasma for use in a processing tool including a plasma-based ion source. [0003] Currently, plasma is used to process substrates such as electronic devices for applications such as substrate etching, layer deposition, ion implantation, and other processes. Some processing apparatuses employ a plasma chamber that generates plasma, which acts as an ion source for substrate processing. The ion beam can be extracted by an extraction assembly and directed towards the substrate in an adjacent chamber. This plasma can be generated in various ways. [0004] In various commercial systems, antenna structures are used to generate inductively coupled plasma (ICP). The antenna is excited using an RF power supply and used to connect to a chamber containing an ionizing gas, where the antenna is isolated from the ionizing gas by a dielectric material such as a dielectric window or dielectric shield. [0005] The RF current within the antenna induces a time-varying magnetic field B(t) that penetrates the plasma through the dielectric material. This B(t) flux induces an RF circular electric field E(t) and a current Ip(t) in the plasma. Plasma electrons gain energy from the electric field, ionizing the gaseous neutral material and thus maintaining the plasma equilibrium density. In an ICP source, the plasma density is proportional to the antenna magnetic flux penetrating the plasma, and the RF power transfer efficiency depends on the magnetic coupling between the antenna and the plasma. [0006] To facilitate magnetic coupling, the antenna is positioned near the dielectric window, where capacitive coupling between the antenna and the dielectric, as well as adverse effects from the electric field-plasma sheath within the dielectric material, occur. Plasma ions reaching the plasma edge adjacent to the plasma sheath are accelerated by this electric field toward the dielectric material (e.g., the dielectric window), and this acceleration can generate enough energy for the plasma ions to cause erosion of the dielectric window and material sputtering. The erosion rate strongly depends on the magnitude of the voltage generated across the plasma sheath. In many types of plasma processing equipment, the RF sheath voltage should be minimized to below a certain threshold level to avoid such adverse effects that occur when ions reach a certain threshold energy. [0007] In practical ICP sources, electrostatic (capacitive) coupling of the antenna to the plasma generates an additional RF voltage across the plasma boundary sheath (or simply "plasma sheath"). In certain antenna designs, such as the ends of a loop antenna with two ends, the plasma sheath voltage can become unacceptably high, exceeding the sputtering threshold and causing material to be sputtered from the vicinity of the dielectric window. [0008] Known ICP antenna designs may include a Faraday shield structure placed between the antenna and the dielectric window, such that the Faraday shield plays a role in reducing the accompanying magnitude of capacitive coupling and RF sheath voltage. One drawback of using a Faraday shield is that it reduces magnetic coupling from the antenna to the plasma, and consequently reduces antenna power loss and power demand from the RF source. [0009] This disclosure is provided in relation to these and other considerations. [0010] In one embodiment, an antenna assembly is provided. The antenna assembly may include an antenna having a loop structure and a dielectric window adjacent to the antenna. The antenna assembly may also include a Faraday shield assembly disposed between the antenna and the dielectric window, the Faraday shield assembly being at least partially disposed around the antenna. The Faraday shield assembly may include a plurality of metal sections electrically insulated from each other, the plurality of metal sections being arranged in a plurality of shield pairs. Thus, the first and second metal sections of a given shield pair may be arranged opposite each other and electrically connected to each other. [0011] In another embodiment, a plasma source is provided. The plasma source may include a plasma chamber surrounding a plasma space containing plasma, and an antenna assembly disposed within or adjacent to the plasma chamber. The antenna assembly may include an antenna having a loop structure and a dielectric window adjacent to the antenna. The antenna assembly may also include a Faraday shield assembly disposed between the antenna and the dielectric window, the Faraday shield assembly being at least partially disposed around the antenna. The Faraday shield assembly may include