Granted Patent B2

US 12,626,895 · App. 17/907,067 · Granted May 12, 2026

Inventors: Sunil Kapoor (Vancouver, WA); David French (Fort Myers, FL); Gary Lemson (San Jose, CA); Liang Meng (Sherwood, OR)

Assignee: Lam Research Corporation

H01J37/32935G01R15/16G01R15/183G01R19/16528G01R19/2509G01R25/00G01R35/007H01J37/32183H01J37/32926H01L21/67161H01L21/67253

Abstract

Claims (28)

1 . An apparatus to estimate parameters of a radio frequency (RF) signal coupled to an integrated circuit fabrication chamber comprising a plurality of stations, comprising:

a plurality of voltage sensors, each configured to provide an indication of a voltage of the RF signal;

a plurality of current sensors, each configured to provide an indication of a current conducted by the RF signal;

a multiplexer configured to:

select a voltage sensor of the plurality of voltage sensors and a current sensor of the plurality of current sensors, wherein the selected voltage sensor and the selected current sensor correspond to a selected station of the plurality of stations; and

provide outputs of the selected voltage and the selected current sensor to an analog-to-digital converter,

the analog-to-digital converter configured to receive outputs from the voltage sensor and the current sensor and configured to provide digital representations of the voltage of the RF signal and the current conducted by the RF signal based on the outputs from the voltage sensor and the current sensor; and

one or more processors configured to determine, based on the digital representations of the voltage and the current of the RF signal: a peak voltage associated with the digital representation of the voltage, a peak current associated with the digital representation of the current, and power characteristics associated with the RF signal.

2 . The apparatus of claim 1 , wherein the one or more processors are further configured to determine phases associated with the digital representations of the voltage and the current.

3 . The apparatus of claim 2 , wherein the power characteristics are based on the determined phases.

4 . The apparatus of claim 1 , wherein the one or more processors are further configured to determine an impedance based on the peak voltage and the peak current.

5 . The apparatus of claim 1 , wherein the voltage sensor comprises a capacitive voltage sensor.

6 . The apparatus of claim 1 , wherein the current sensor comprises an inductive transformer.

7 . The apparatus of claim 1 , wherein the RF signal is provided by an RF power generator that provides at least 2 frequency components.

8 . The apparatus of claim 1 , wherein the RF signal is provided by an RF power generator that provides one frequency component.

9 . The apparatus of claim 1 , wherein the one or more processors comprise a Field Programmable Gate Array (FPGA).

10 . The apparatus of claim 1 , wherein the digital representations are at a sampling rate typically greater than about 100 MHz.

11 . The apparatus of claim 1 , wherein the power characteristics comprise a power factor.

12 . The apparatus of claim 1 , wherein the one or more processors are further configured to communicate data via a serial communication protocol, via Ethernet, or via another digital communication protocol.

13 . The apparatus of claim 1 , wherein the one or more processors are further configured to provide outputs to an Ethernet for Control Automation Technology (EtherCAT) system.

14 . The apparatus of claim 13 , wherein the EtherCAT system is configured to provide instructions to one or more elements in a matching network or other RF distribution system.

15 . The apparatus of claim 1 , wherein the one or more processors are configured to: 1) provide calibration coefficients to the voltage sensor for storage in memory associated with the voltage sensor; or 2) provide calibration coefficients to the current sensor for storage in memory associated with the current sensor.

16 . The apparatus of claim 15 , wherein the calibration coefficients are determined for a plurality of RF signal frequencies.

17 . The apparatus of claim 15 , wherein the calibration coefficients are determined using a modular calibration method that comprises: determining an effect of one or more cables that electrically couple the voltage sensor and the current sensor to the analog-to-digital converter; or determining an effect of a controller that receives outputs from the voltage sensor and the current sensor via the one or more cables.

18 . The apparatus of claim 15 , wherein the calibration coefficients are determined using an end-to-end calibration method that comprises determining transformation functions that relate outputs of the one or more processors to characteristics of the RF signal.

19 . The apparatus of any one of claim 15 , wherein: 1) the voltage sensor is configured to provide identifying information to the one or more processors; or 2) the current sensor is configured to provide identifying information to the one or more processors.

20 . The apparatus of claim 19 , wherein the identifying information comprises the calibration coefficients.

21 . The apparatus of claim 19 , wherein 1) the voltage sensor is configured to provide identifying information to the one or more processors at a system power on time or a system reset time; or 2) the current sensor is configured to provide identifying information to the one or more processors at the system power on time or the system reset time.

Assignments (1)

Continuity (2)

References Cited (400)