# US 2026/0100334 A1 · High power and large area uniform microwave plasma source

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- Number: US 2026/0100334 A1
- Document ID: US20260100334A1
- Status: Published application
- Kind: A1
- Application number: 18/908,437
- Filed: 2024-10-07
- Published: 2026-04-09
- Earliest claimed: 2024-10-07
- Assignees: Applied Materials, Inc.
- Applicants: Applied Materials, Inc.
- Inventors: XIAOKANG YANG
- Web page: https://patentgrep.com/patent/US20260100334A1

## CPC

- H01J 37/32229: {Waveguides}
- H01J 37/32192: {Microwave generated discharge (H01J37/32357, H01J37/32366, H01J37/32394, H01J37/32403 take precedence)}
- H01J 37/32201: {Generating means}
- H01J 37/32211: {Means for coupling power to the plasma}
- H01J 37/3222: {Antennas}
- H01J 37/32311: {Circuits specially adapted for controlling the microwave discharge}
- H01J: ELECTRIC DISCHARGE TUBES OR DISCHARGE LAMPS (spark-gaps H01T; electric arc lamps H05B31/00; particle accelerators H05H)

## Abstract

Embodiments described herein relate to an apparatus that includes a microwave power generator, and a rectangular waveguide coupled to the microwave power generator. In an embodiment, the apparatus may also include an impedance tuner that is coupled to the rectangular waveguide, and a coaxial waveguide that is coupled to the rectangular waveguide. In an embodiment, the coaxial waveguide includes a conductive pin with a first end and a second end. In an embodiment, the apparatus further includes a circular waveguide cavity around the second end of the conductive pin, and a slotted antenna in the circular waveguide cavity.

## Claims

### Claim 1

An apparatus, comprising:
a microwave power generator;
a rectangular waveguide coupled to the microwave power generator;
an impedance tuner coupled to the rectangular waveguide;
a coaxial waveguide coupled to the rectangular waveguide, wherein the coaxial waveguide comprises a conductive pin with a first end and a second end;
a circular waveguide cavity around the second end of the conductive pin; and
a slotted antenna in the circular waveguide cavity.

### Claim 2 (depends on 1)

The apparatus of claim 1, wherein the microwave power generator is a solid-state power amplifier based power generator or a magnetron-based microwave power generator.

### Claim 3 (depends on 1)

The apparatus of claim 1, wherein the microwave power generator has a power rating of at 3 kW or more.

### Claim 4 (depends on 1)

The apparatus of claim 1, wherein the impedance tuner is a multi-stub impedance tuner.

### Claim 5 (depends on 1)

The apparatus of claim 1, further comprising a plunger at an end of the microwave waveguide.

### Claim 6 (depends on 1)

The apparatus of claim 1, wherein one or both of the first end or the second end of the conductive pin comprise a non-uniform width.

### Claim 7 (depends on 1)

The apparatus of claim 1, wherein the slotted antenna comprises a multi-hole slot antenna, an annular ring slot antenna, a four-rectangular slot antenna, or a radial slot antenna.

### Claim 8 (depends on 1)

The apparatus of claim 1, wherein the slotted antenna is provided over a dielectric plate that seals a chamber configured to support plasma generation.

### Claim 9 (depends on 8)

The apparatus of claim 8, wherein a width of the slotted antenna is smaller than a width of the dielectric plate.

### Claim 10 (depends on 1)

The apparatus of claim 1, wherein the impedance tuner is a manual stub tuner or an autotuning stub tuner.

### Claim 11

An apparatus, comprising:
a microwave plasma source, comprising:
a microwave power generator;
a rectangular waveguide coupled to the microwave power generator;
an impedance tuner coupled to the rectangular waveguide;
a coaxial waveguide coupled to the impedance tuner;
a circular waveguide cavity coupled to the coaxial waveguide; and
a slot antenna within the circular waveguide cavity; and
a plasma chamber coupled to the microwave plasma source, wherein the plasma chamber comprises:
a chamber housing; and
a dielectric plate to seal an opening of the chamber housing,
wherein the slot antenna is on a surface of the dielectric plate outside of the chamber housing.

### Claim 12 (depends on 11)

The apparatus of claim 11, wherein the coaxial waveguide is directly coupled to the impedance tuner.

### Claim 13 (depends on 12)

The apparatus of claim 12, further comprising:
a plunger within the circular waveguide cavity.

### Claim 14 (depends on 11)

The apparatus of claim 11, wherein the coaxial waveguide is coupled to the rectangular waveguide, and wherein the impedance tuner is between a first end of the rectangular waveguide and a second end of the rectangular waveguide.

### Claim 15 (depends on 14)

The apparatus of claim 14, further comprising:
a plunger at the second end of the rectangular waveguide.

### Claim 16 (depends on 11)

The apparatus of claim 11, wherein the slot antenna is a multi-hole slot antenna, an annular ring slot antenna, a four-rectangular slot antenna, or a radial slot antenna.

### Claim 17 (depends on 11)

The apparatus of claim 11, wherein a conductive pin of the coaxial waveguide directly contacts the slot antenna.

### Claim 18

An apparatus, comprising:
a microwave plasma source that comprises:
a microwave power generator;
a microwave power transmission path that comprises a first region configured to propagate TE mode microwave power, a second region configured to propagate TEM mode microwave power, and a third region configured to propagate TM mode microwave power; and
a slotted antenna coupled to the third region of the microwave power transmission path; and
a chamber coupled to the microwave plasma source, wherein the chamber comprises:
a chamber housing; and
a dielectric plate to seal an opening of the chamber housing, wherein the slotted antenna is on the dielectric plate outside of the chamber housing.

### Claim 19 (depends on 18)

The apparatus of claim 18, wherein the first region of the microwave power transmission path comprises a rectangular waveguide, wherein the second region of the microwave power transmission path comprises a coaxial waveguide, and wherein the third region of the microwave power transmission path comprises a circular waveguide cavity.

### Claim 20 (depends on 18)

The apparatus of claim 18, wherein the slotted antenna is configured to induce a surface wave on a surface of the dielectric plate within the chamber housing.