ELECTROMAGNETIC WAVE TREATMENT OF A SUBSTRATE AT MICROWAVE FREQUENCIES USING A WAVE RESONATOR

• US 20170084462A1
• Filed: 08/29/2016
• Published: 03/23/2017
• Est. Priority Date: 09/23/2015
• Status: Active Grant

• Current Assignee: Tokyo Electron Limited
• Original Assignee: Tokyo Electron Limited
• Inventors: Vukovic, Mirko
• Granted Patent: US 10,522,384 B2
• Time in Patent Office: Days
• CPC Class Codes: H01L 21/324 Thermal treatment for modifying the properties of semiconductor bodies, e.g. annealing, sintering H01L21/20 - H01L21/288 and H01L21/302 - H01L21/322 take precedence
• CPC Class Codes: H01L 21/67115 mainly by radiation
• CPC Class Codes: H01L 21/68714 the wafers being placed on a susceptor, stage or support
• CPC Class Codes: H01P 1/182 Waveguide phase-shifters H01P1/181, H01P1/185, H01P1/19 take precedence
• CPC Class Codes: H01P 1/38 Circulators
• CPC Class Codes: H01P 3/12 Hollow waveguides H01P3/20 takes precedence
• CPC Class Codes: H01P 7/06 Cavity resonators
• CPC Class Codes: H01Q 13/22 Longitudinal slot in boundary wall of waveguide or transmission line H01Q13/203 takes precedence
• CPC Class Codes: H01Q 21/0043 Slotted waveguides combination with horns H01Q13/0233

Abstract

A processing system is disclosed, having a process chamber that houses a substrate for exposure of a surface of the substrate to a travelling electromagnetic (EM) wave. The processing system also includes an EM wave transmission antenna configured to launch the travelling EM wave into the process chamber for the travelling EM wave to propagate in a direction substantially parallel to the surface of the substrate. The processing system also includes a power coupling system configured to supply EM energy into the EM wave transmission antenna to generate the travelling EM wave at a prescribed output power and in a prescribed EM wave mode during treatment of the substrate. The EM wave is recycled in the processing system in order to increase the efficiency of the microwave power use and eliminate the complexity of the resistive load cooling.

Claims

1. A processing system for electromagnetic (EM) wave treatment of a substrate, comprising:

an EM wave generator configured to generate a EM wave at a prescribed output power and a prescribed wave mode, the EM wave generator coupled to a first waveguide;

a standing wave circuit (SWC) coupled to the first waveguide, the standing wave circuit configured to reflect back or allow an EM wave to pass through, the standing wave circuit comprising;

an impedance matcher coupled to the first waveguide and configured to reflect back or allow an EM wave to pass through; and

a travelling wave circuit (TWC) coupled to the standing wave circuit, the travelling wave circuit comprising;

a circulator configured to redirect a flow of the travelling EM wave and generate a travelling EM wave;

a process chamber configured to house a substrate for exposure of a surface of the substrate to the travelling EM wave; and

a phase shifter configured to insure a whole number of wavelengths exist in the traveling wave circuit and in the standing wave circuit;

wherein the travelling EM wave is recirculated through the SWC and TWC thereby reducing the power usage by the SWC and wherein the processing system for EM wave treatment does not require a resistive load device to unload the travelling EM wave.

2. The processing system of claim 1, wherein the EM wave generator is configured to generate the EM wave at a microwave frequency in a range of 1 GHz to 10 GHz or in a range from 0.10 to 0.99 GHz.

3. The processing system of claim 1, wherein the EM wave treatment of the substrate is for a thermal annealing process or dopant activation process.

5. The processing system of claim 1, wherein the travelling wave circuit further comprises:

a waveguide configuration that includes a fourth waveguide, a fifth waveguide, a sixth waveguide, and a seventh waveguide;

wherein the fourth waveguide is oriented for the travelling EM wave to exit the circulator and bend left substantially 90 degrees prior to entering the process chamber in a direction substantially parallel to the surface of the substrate,

wherein the fifth waveguide is oriented for the travelling EM wave exit straight out of the process chamber, to proceed straight then bend left substantially 90 degrees, continue straight, and bend another left substantially 90 degrees prior to entering into the sixth waveguide;

wherein the sixth waveguide is oriented for the travelling EM wave to proceed straight and enter the phase shifter; and

wherein the seventh waveguide is oriented for the travelling EM wave to exit the phase shifter, proceed straight and enter circulator.

6. The processing system of claim 1, wherein:

the impedance matcher is tuned such that less than 20% of the EM energy is reflected back to the EM wave generator.

7. The processing system of claim 1 wherein the standing wave circuit and travelling wave circuit functions as a ring resonator to recirculate the EM energy over the substrate in order to reduce costs of ownership of the EM wave generator.

8. The processing system of claim 1 wherein recirculation of the EM energy eliminates complexity of thermal annealing and dopant activation processes and reduces a need for cooling of the substrate.

9. The processing system of claim 1 further comprising a controller coupled to the process chamber, the controller configured to control two or more operating variables of the processing system in order to meet EM treatment objectives including thermal annealing, dopant activation, cost of ownership, substrate throughput targets.

10. The processing system of claim 1 wherein the uniformity of a dopant anneal process can be improved through 1) varying the substrate rotation, 2) shaping of the process chamber profile, and/or 3) adding dielectric lenses to the process chamber.

4. The processing system of claim 4, wherein the substrate surface is at or below 400 degrees C., at or below 360 degrees C., or at below 340 degrees C.

11. A processing system for electromagnetic (EM) wave treatment of a substrate, the processing system comprising:

an EM wave generator configured to generate an EM wave at a prescribed output power and a prescribed wave mode, the EM wave generator coupled to a first waveguide;

a travelling wave circuit coupled to the EM wave generator, the travelling wave circuit configured to reflect back or allow an EM wave to pass through, the travelling wave circuit comprising;

a first impedance matcher coupled to the EM wave generator and configured to reflect back or allow an EM wave to pass through;

a standing wave resonator coupled to the travelling wave circuit, the standing wave resonator configured to generate a travelling EM wave and recirculate the travelling EM wave, the standing wave resonator comprising;

a circulator coupled configured to redirect a flow of the travelling EM wave;

a slot wave antenna configured to propagate a travelling EM wave; and

a first phase shifter configured to insure a whole number of wavelengths exist in the traveling wave circuit and in the standing wave resonator; and

a loop-back travelling wave circuit coupled to the standing wave resonator;

the loop-back travelling wave circuit comprising;

a process chamber coupled to the standing wave antenna and configured to house a substrate for exposure of a surface of the substrate to the travelling EM wave;

a second phase shifter configured to insure a whole number of wavelengths exist in the loop-back travelling wave circuit; and

a second impedance matcher configured to reflect back or allow an EM wave to pass through;

wherein the travelling EM wave is transmitted through the travelling wave circuit and into the standing wave resonator and wherein the travelling EM wave propagates in a direction substantially parallel to a surface of the substrate.

12. The processing system of claim 11, wherein the EM wave generator is configured to generate the EM wave at a microwave frequency in a range of 1 GHz to 10 GHz or in a range from 0.10 to 0.99 GHz.

13. The processing system of claim 11, wherein the EM wave treatment of the substrate is for thermal annealing and/or dopant activation application.

14. The processing system of claim 11, the standing wave circuit further comprising:

a second waveguide coupled to the impedance matcher and the circulator.

15. The processing system of claim 11, wherein:

the first impedance matcher is tuned such that less than 20% of the EM energy is reflected back to the EM generator.

16. The processing system of claim 11, wherein the travelling wave circuit, the standing wave resonator, and the loop-back travelling wave circuit function as a resonator to recirculate the EM energy over the substrate in order to reduce costs of the EM wave generator.

17. The processing system of claim 11, wherein recirculation of the EM energy eliminates complexity of thermal annealing and dopant activation processes and reduces a need for cooling of the substrate.

18. The processing system of claim 11, wherein the substrate surface is at or below 400 degrees, at or below 360 degrees C., or at below 340 degrees C.

19. The processing system of claim 11, wherein the standing wave resonator and loop-back travelling wave circuit recirculate the EM energy in order to reduce costs of ownership of the EM wave generator.

20. The processing system of claim 11 wherein the uniformity of a dopant anneal process can be improved through 1) varying the substrate rotation, 2) shaping of the process chamber profile, and/or 3) adding dielectric lenses to the process chamber.

21. A method for treating a substrate with electromagnetic (EM) energy, comprising:

disposing a substrate on a substrate holder in a process chamber;

launching a travelling EM wave into the process chamber to propagate in a direction substantially parallel to a surface of the substrate;

exposing the surface of the substrate to the travelling EM wave as the travelling EM wave propagates through the process chamber in the direction substantially parallel to the surface of the substrate; and

recirculating the travelling EM wave after the travelling EM wave propagates through the process chamber.

22. The method of claim 21, wherein the launching includes coupling an output end of an EM wave transmission antenna to an input port of the process chamber, and supplying EM energy into the EM wave transmission antenna to generate the travelling EM wave at a prescribed output power and in a prescribed EM wave mode during the exposing;

and

wherein the recirculating includes coupling an output end of a standing wave antenna to an input port of the standing wave resonator.

23. The method of claim 21, wherein the EM energy is supplied to generate the travelling EM wave at a microwave frequency in a range of 1 GHz to 10 GHz or in a range from 0.1 to 0.99 GHz.

24. The method of claim 21 wherein the uniformity of a dopant anneal process can be improved through 1) varying the substrate rotation, 2) shaping of the process chamber profile, and/or 3) adding dielectric lenses to the process chamber.

25. The method of claim 21, wherein the launching further comprises:

launching the travelling EM wave through a plurality of slots in a wall of a waveguide section included in a slot wave antenna.

26. The method of claim 21 further comprising:

concurrently controlling two or more selected operating variables of the method for treating a substrate with electromagnetic (EM) energy in order to achieve objectives of the treating of the substrate.