Etch rate modeling and use thereof for in-chamber and chamber-to-chamber matching

• US 9,082,594 B2
• Filed: 06/27/2014
• Issued: 07/14/2015
• Est. Priority Date: 07/26/2013
• Status: Active Grant

• Current Assignee: Lam Research Corporation
• Original Assignee: Lam Research Corporation
• Inventors: Valcore, John C. Jr., Singh, Harmeet, Povolny, Henry
• Primary Examiner(s): VU, JIMMY T
• Application Number:
  US14/317,360
• Publication Number:
  US 20150028744A1
• Time in Patent Office: 382 Days
• Field of Search: 315/111.01, 315/111.21, 315/111.41, 315/111.51, 315/111.71, 156/345.21, 156/345.28, 156/345.48
• US Class Current: 1/1
• CPC Class Codes: G05B 19/418 Total factory control, i.e. centrally controlling a plurality of machines, e.g. direct or distributed numerical control [DNC], flexible manufacturing systems [FMS], integrated manufacturing systems [IMS] or computer integrated manufacturing [CIM]
• CPC Class Codes: H01J 37/32183 Matching circuits
• CPC Class Codes: H01J 37/32926 Software, data control or modelling
• CPC Class Codes: H01J 37/32935 Monitoring and controlling tubes by information coming from the object and/or discharge
• CPC Class Codes: H01J 37/3299 Feedback systems

Abstract

A method for performing chamber-to-chamber matching includes receiving a voltage and a current measured at an output of an RF generator of a first plasma system. The method further includes calculating a sum of terms. The first term is a first product of a coefficient and a function of the voltage. The second term is a second product of a coefficient and a function of the current. The third term is a third product of a coefficient, a function of the voltage, and a function of the current. The method further includes determining the sum to be the etch rate associated with the first plasma system and adjusting power output from an RF generator of a second plasma system to achieve the etch rate associated with the first plasma system.

Claims

1. A method comprising:

receiving a voltage and a current measured at an output of a radio frequency (RF) generator of a first plasma system;

calculating a sum of a first term, a second term, and a third term, wherein the first term is a first product of a coefficient and a function of the voltage, the second term is a second product of a coefficient and a function of the current, and the third term is a third product of a coefficient, a function of the voltage, and a function of the current;

determining the sum to be the etch rate associated with the first plasma system; and

adjusting power output from an RF generator of a second plasma system to achieve the etch rate associated with the first plasma system,

wherein the method is executed by a processor.

2. The method of claim 1, wherein the RF generator of the first plasma system is coupled to an impedance matching circuit via a cable, and wherein the impedance matching circuit is coupled to a plasma chamber via an RF transmission line.

3. The method of claim 1, wherein the function of the voltage in the first product or the third product includes a mathematical power function of the voltage measured at the output of the RF generator of the first plasma system, and the function of the current in the second product or the third product includes a mathematical power function of the current measured at the output of the RF generator of the first plasma system.

4. The method of claim 1, wherein receiving the voltage and the current measured at the output of the RF generator of the first plasma system is performed using a dummy wafer in a plasma chamber of the first plasma system.

5. The method of claim 1, wherein the output of the RF generator of the first plasma system is coupled to an input of an impedance matching circuit, wherein the output facilitates a transfer of an RF signal to a plasma chamber via the impedance matching circuit.

6. The method of claim 1, wherein adjusting the power output from the RF generator of the second plasma system is performed when the second plasma system is used to etch a semiconductor wafer.

7. The method of claim 1, wherein adjusting the power includes increasing or decreasing the power output from the RF generator of the second plasma system.

8. The method of claim 1, wherein the first plasma system includes a tool that is identical in function to a tool of the second plasma system and has a different identification than that of the second plasma system.

9. The method of claim 1, wherein the first plasma system includes a tool that is identical in structure to a tool of the second plasma system and has a different identification than that of the second plasma system.

10. The method of claim 1, wherein the first plasma system includes a tool that is identical in structure and function to a tool of the second plasma system and has a different identification than that of the second plasma system.

11. The method of claim 1, wherein the sum is a Taylor series.

12. A method comprising:

receiving a voltage and a current measured at a first time at an output of a radio frequency (RF) generator of a plasma system;

calculating a sum of a first term, a second term, and a third term, wherein the first term is a first product of a coefficient and a function of the voltage, the second term is a second product of a coefficient and a function of the current, and the third term is a third product of a coefficient, a function of the voltage, and a function of the current;

determining the sum to be the etch rate associated with the plasma system; and

adjusting power output at a second time from the RF generator of the plasma system to achieve the etch rate,

wherein the method is executed by a processor.

13. The method of claim 12, wherein the output of the RF generator is coupled to an input of an impedance matching circuit, wherein the output is used to facilitate transfer of an RF signal to a plasma chamber via the impedance matching circuit.

14. The method of claim 12, wherein the second time occurs after the first time.

15. The method of claim 12, wherein the function of the voltage in the first product or the third product includes a mathematical power function of the voltage measured at the first time, and the function of the current in the second product or the third product includes a mathematical power function of the current measured at the first time.

16. The method of claim 12, wherein receiving the voltage and the current measured at the first time at the output of the RF generator of the plasma system is performed using a dummy wafer in a plasma chamber of the plasma system.

17. The method of claim 12, wherein the output of the RF generator of the plasma system is coupled to an input of an impedance matching circuit, the impedance matching circuit used to match an impedance of a plasma chamber of the plasma system and an RF transmission line coupled to the plasma chamber with an impedance of an RF cable coupled to the RF generator and the RF generator.

18. The method of claim 12, wherein adjusting the power at the second time at the output of the RF generator of the plasma system is performed when the plasma system is used to etch a semiconductor wafer.

19. A plasma system for modeling an etch rate, the plasma system comprising:

a radio frequency (RF) generator for generating an RF signal, the RF generator including an output for facilitating transfer of the RF signal;

a complex impedance sensor coupled to the output of the RF generator for measuring a complex voltage and current of the RF signal;

a plasma chamber for generating plasma when the RF signal is received;

an impedance matching circuit coupled to the RF generator via a cable and coupled to the plasma chamber via an RF transmission line;

a processor coupled to the complex impedance sensor for receiving the measurement of the complex voltage and current from the complex impedance sensor, the processor for;

receiving a voltage and a current measured at an output of an RF generator of a second plasma system;

calculating a sum of a first term, a second term, and a third term, wherein the first term is a first product of a coefficient and a function of the voltage measured at the output of the second plasma system, and the second term is a second product of a coefficient and a function of the current measured at the output of the RF generator of the second plasma system, and the third term is a third product of a coefficient, a function of the voltage measured at the output of the RF generator of the second plasma system, and a function of the current measured at the output of the RF generator of the second plasma system;

determining the sum to be the etch rate associated with the second plasma system; and

adjusting power at the output of the RF generator of the first plasma system to achieve the etch rate associated with the second plasma system, wherein adjusting the power is based on the complex voltage and current.

20. The plasma system of claim 19, wherein the first plasma system includes a tool that is identical in function to a tool of the second plasma system and has a different identification than that of the second plasma system.