Adjustment of power and frequency based on three or more states

• US 9,462,672 B2
• Filed: 09/03/2013
• Issued: 10/04/2016
• Est. Priority Date: 02/22/2012
• Status: Active Grant

• Current Assignee: Lam Research Corporation
• Original Assignee: Lam Research Corporation
• Inventors: Valcore, John C. Jr., Lyndaker, Bradford J.
• Primary Examiner(s): Lund, Jeffrie R
• Assistant Examiner(s): Yu, Yuechuan
• Application Number:
  US14/016,841
• Publication Number:
  US 20140009073A1
• Time in Patent Office: 1,127 Days
• US Class Current: 1/1
• CPC Class Codes: H01J 37/244 Detectors; Associated components or circuits therefor
• CPC Class Codes: H01J 37/32082 Radio frequency generated discharge H01J37/32357, H01J37/32366, H01J37/32394 and H01J37/32403 take precedence
• CPC Class Codes: H01J 37/32137 controlling of the discharge by modulation of energy
• CPC Class Codes: H01J 37/32146 Amplitude modulation, includes pulsing
• CPC Class Codes: H01J 37/32155 Frequency modulation
• CPC Class Codes: H01J 37/32174 Circuits specially adapted for controlling the RF discharge
• CPC Class Codes: H01J 37/32183 Matching circuits
• CPC Class Codes: H03J 7/00 Automatic frequency control; Automatic scanning over a band of frequencies
• CPC Class Codes: H05H 1/46 using applied electromagnetic fields, e.g. high frequency or microwave energy H05H1/26 takes precedence

Abstract

Systems and methods for adjusting power and frequency based on three or more states are described. One of the methods includes receiving a pulsed signal having multiple states. The pulsed signal is received by multiple radio frequency (RF) generators. When the pulsed signal having a first state is received, an RF signal having a pre-set power level is generated by a first RF generator and an RF signal having a pre-set power level is generated by a second RF generator. Moreover, when the pulsed signal having a second state is received, RF signals having pre-set power levels are generated by the first and second RF generators. Furthermore, when the pulsed signal having a third state is received, RF signals having pre-set power levels are generated by the first and second RF generators.

Claims

1. A plasma processing system, comprising,

a primary generator including three primary power controllers, each of the primary power controllers configured with a predefined power setting;

a secondary generator including three secondary power controllers, each of the secondary power controllers configured with a predefined power setting; and

a control circuit interfaced as an input to each of the primary and secondary generators, the control circuit configured to generate a pulsed signal, the pulsed signal defined to include three states that define a cycle that repeats during operation for a plurality of cycles, each state defined to select a first, or a second, or a third of the three primary power controllers while also selecting a first, or a second, or a third of the three secondary power controllers.

2. The plasma processing system of claim 1, wherein the primary generator includes three primary auto frequency tuners (AFTs), each of the primary AFTs configured with a predefined frequency setting, wherein the secondary generator includes three secondary AFTs, each of the secondary AFTs configured with a predefined frequency setting, each state defined to select a first, or a second, or a third of the three primary AFTs while also selecting a first, or a second, or a third of the three secondary AFTs.

3. The plasma processing system of claim 1, wherein the primary generator includes a primary radio frequency (RF) generator and the secondary generator includes a secondary RF generator.

4. The plasma processing system of claim 1, wherein the primary power controllers are parts of a processor of the primary generator, wherein the secondary power controllers are parts of a processor of the secondary generator.

5. The plasma processing system of claim 1, wherein the pulsed signal is a digital pulsed signal.

6. The plasma processing system of claim 3, wherein the operation includes an operation of the primary and secondary RF generators.

7. A plasma system configured for operation using multiple states, the plasma system comprising:

a primary radio frequency (RF) generator for receiving a pulsed signal, the pulsed signal having three or more states, the three or more states including a first state, a second state, and a third state, the primary RF generator for coupling to a plasma chamber via an impedance matching circuit,

a secondary RF generator for receiving the pulsed signal, the secondary RF generator for coupling to the plasma chamber via the impedance matching circuit,

each of the primary RF generator and the secondary RF generator has a controller that is configured to determine whether the pulsed signal is in the first state, or the second state, or the third state,

the primary RF generator'"'"'s controller is configured to determine that the pulsed signal is in the first state, and in response, controls the primary RF generator to provide an RF signal having a first primary quantitative level to the impedance matching circuit,

the secondary RF generator'"'"'s controller is configured to determine that the pulsed signal is in the first state, and in response, controls the secondary RF generator to provide an RF signal having a first secondary quantitative level to the impedance matching circuit,

the primary RF generator'"'"'s controller is configured to determine that the pulsed signal is in the second state, and in response, controls the primary RF generator to provide an RF signal having the first primary quantitative level to the impedance matching circuit,

the secondary RF generator'"'"'s controller is configured to determine that the pulsed signal is in the second state, and in response, controls the secondary RF generator to provide an RF signal having a second secondary quantitative level to the impedance matching circuit,

the primary RF generator'"'"'s controller is configured to determine that the pulsed signal is in the third state, and in response, controls the primary RF generator to provide an RF signal having a second primary quantitative level to the impedance matching circuit,

the secondary RF generator'"'"'s controller is configured to determine that the pulsed signal is in the third state, and in response, controls the secondary RF generator to provide an RF signal having a third secondary quantitative level to the impedance matching circuit.

8. The plasma system of claim 7, wherein the first and second states are associated with a same power level of the primary RF generator.

9. The plasma system of claim 7, wherein the first, second, and third states are associated with different power levels of the primary RF generator.

10. The plasma system of claim 7, wherein the first state occurs during a time period that is equal to a time period of occurrence of the second state.

11. The plasma system of claim 7, wherein the first state occurs during a time period that is unequal to a time period of occurrence of the second state.

12. The plasma system of claim 7, wherein the second state occurs during a time period that is equal to a time period of occurrence of the third state.

13. The plasma system of claim 7, wherein the second state occurs during a time period that is unequal to a time period of occurrence of the third state.

14. The plasma system of claim 7, wherein the first primary quantitative level, the second primary quantitative level, the first secondary quantitative level, the second secondary quantitative level, and the third secondary quantitative level are power levels.

15. The plasma system of claim 7, wherein the first primary quantitative level, the second primary quantitative level, the first secondary quantitative level, the second secondary quantitative level, and the third secondary quantitative level are frequency levels.