Protection system for switches in direct drive circuits of substrate processing systems

Patent metadata

Field	Value
Publication number	US-12261029-B2
Application number	US-202118009575-A
Country	US
Kind code	B2
Filing date	Jun 10, 2021
Priority date	Jun 17, 2020
Publication date	Mar 25, 2025
Grant date	Mar 25, 2025

Abstract

A direct drive system for providing RF power to a component of a substrate processing system includes a direct drive circuit including a switch and configured to supply RF power to the component. A switch protection module is configured to monitor a load current and a load voltage in a processing chamber, calculate load resistance based on the load current and the load voltage, compare the load resistance to a first predetermined load resistance, and adjust at least one of an RF power limit and an RF current limit of the direct drive circuit based on the comparison.

First claim

What is claimed is:

1. A direct drive circuit for providing RF power to a component of a processing chamber associated with a substrate processing system, comprising:
the direct drive circuit including a switch and configured to supply said RF power to the component;
a switch protection module configured to:
monitor a load current and a load voltage in the processing chamber;
calculate load resistance based on the load current and the load voltage;
compare the load resistance to a first predetermined load resistance; and
adjust at least one of an RF power limit and an RF current limit of the direct drive circuit based on the comparison;

wherein the first predetermined load resistance is selected based on a resistance during at least one non-plasma condition.

2. The direct drive circuit of claim 1 , further comprising a voltage/current (VI) probe arranged in the processing chamber and configured to generate the load current and load voltage.

3. The direct drive circuit of claim 1 , wherein the at least one non-plasma condition corresponds to plasma failing to ignite.

4. The direct drive circuit of claim 1 , wherein the at least one non-plasma condition corresponds to plasma dropping out after process gas flow to the process chamber is turned off.

5. The direct drive circuit of claim 1 , wherein the switch protection module reduces the at least one of the RF power limit and the RF current limit of the direct drive circuit in response to the load resistance being less than or equal to the first predetermined load resistance.

6. The direct drive circuit of claim 5 , wherein the switch protection module is configured to shut down the direct drive circuit in response to the load resistance being less than or equal to the first predetermined load resistance for a period greater than a predetermined period.

7. The direct drive circuit of claim 1 , wherein the switch protection module increases the at least one of the RF power limit and the RF current limit of the direct drive circuit in response to the load resistance being less than or equal to the first predetermined load resistance.

8. The direct drive circuit of claim 7 , wherein the switch protection module is configured to shut down the direct drive circuit in response to the load resistance being less than or equal to the first predetermined load resistance for a period greater than a predetermined period.

9. The direct drive circuit of claim 1 , wherein:
the switch protection module selects at least one of a first RF power limit and a first RF current limit of the direct drive circuit in response to the load resistance being less than or equal to the first predetermined load resistance and at least one of a second RF power limit and a second RF current limit of the direct drive circuit in response to the load resistance being greater than the first predetermined load resistance,
the at least one of a first RF power limit and the first RF current limit of the direct drive circuit is less than the at least one of the second RF power limit and the second RF current limit of the direct drive circuit, respectively, and
the switch protection module is configured to shut down the direct drive circuit in response to the load resistance being less than or equal to the first predetermined load resistance for a period greater than a predetermined period.

10. The direct drive circuit of claim 1 , wherein:
the switch protection module selects at least one of a first RF power limit and a first RF current limit of the direct drive circuit in response to the load resistance being less than or equal to the first predetermined load resistance and at least one of a second RF power limit and a second RF current limit of the direct drive circuit in response to the load resistance being greater than the first predetermined load resistance,
the at least one of a first RF power limit and the first RF current limit of the direct drive circuit is greater than the at least one of the second RF power limit and the second RF current limit of the direct drive circuit, respectively, and
the switch protection module is configured to shut down the direct drive circuit in response to the load resistance being less than or equal to the first predetermined load resistance for a period greater than a predetermined period.

11. The direct drive circuit of claim 1 , wherein the switch protection module is configured to shut down the direct drive circuit in response to the load resistance being less than or equal to the first predetermined load resistance for a period greater than a predetermined period.

12. The direct drive circuit of claim 1 , wherein the direct drive circuit includes:
a clock generator to generate a clock signal at a first frequency;
a gate driver to receive the clock signal;
a bridge circuit including:
a first switch with a control terminal connected to the gate driver, a first terminal and a second terminal; and
a second switch with a control terminal connected to the gate driver, a first terminal connected to the second terminal of the first switch and an output node, and a second terminal.

13. The direct drive circuit of claim 12 , further comprising:
a current sensor to sense current at the output node and to generate a current signal;
a voltage sensor to sense voltage at the output node and to generate a voltage signal; and
a controller including:
a phase offset calculating module to calculate a phase offset between the voltage signal and the current signal; and
a clock adjusting module to adjust the first frequency based on the phase offset.

14. The direct drive circuit of claim 13 , wherein the component comprises a coil arranged outside of the processing chamber.

15. A method for providing RF power to a component of a processing chamber associated with a substrate processing system, comprising:
supplying said RF power to the component using a direct drive circuit including a switch;
monitoring a load current and a load voltage in the processing chamber;
calculating load resistance based on the load current and the load voltage;
comparing the load resistance to a first predetermined load resistance; and
adjusting at least one of an RF power limit and an RF current limit of the direct drive circuit based on the comparison;
wherein the first predetermined load resistance is selected based on a resistance during at least one non-plasma condition.

16. The method of claim 15 , further comprising arranging a voltage/current (VI) probe in the processing chamber and generating the load current and load voltage using the VI probe.

17. The method of claim 15 , wherein the at least one non-plasma condition corresponds to plasma failing to ignite.

18. The method of claim 15 , wherein the at least one non-plasma condition corresponds to plasma dropping out after process gas flow to the process chamber is turned off.

19. The method of claim 15 , further comprising reducing the at least one of the RF power limit and the RF current limit of the direct drive circuit in response to the load resistance being less than or equal to the first predetermined load resistance.

20. The method of claim 19 , further comprising shutting down the direct drive circuit in response to the load resistance being less than or equal to the first predetermined load resistance for a period greater than a predetermined period.

21. The method of claim 15 , further comprising increasing the at least one of the RF power limit and the RF current limit of the direct

Assignees

• Lam Res Corp

Inventors

• Long Maolin
• Wang Yuhou
• Martin Michael John
• Paterson Alexander Miller

Classifications

• H01J37/32082

  Radio frequency generated discharge (H01J37/32357, H01J37/32366, H01J37/32394 and H01J37/32403 take precedence) · CPC title

• G01R27/08

  Measuring resistance by measuring both voltage and current · CPC title

• H02J50/20

  using microwaves or radio frequency waves · CPC title

• Y02B70/10

  Technologies improving the efficiency by using switched-mode power supplies [SMPS], i.e. efficient power electronics conversion e.g. power factor correction or reduction of losses in power supplies or efficient standby modes · CPC title

• H02M7/538

  in a push-pull configuration (H02M7/5375 takes precedence {; with oscillating arrangements H02M7/53832, H02M7/53846}) · CPC title