Granted Patent B1

US 12,584,942 · App. 19/384,994 · Granted Mar 24, 2026

Inventors: Hanaul Noh (Mountain View, CA); Chih-Chieh Hsieh (San Jose, CA); Myunghoon Choi (Santa Clara, CA); Stefan Kaemmer (Santa Barbara, CA)

Assignee: Park Systems Corp.

G01Q60/40G01N22/00G01Q60/34

Abstract

Claims (87)

1 . A measurement system comprising:

an excitation unit configured to generate a microwave excitation towards a sample;

a probe, coupled to the excitation unit, configured to:

scan the sample along a path at a first vertical position relative to the sample,

capture a first microwave response along the path at the first vertical position based on the microwave excitation,

scan the sample along the path at a second vertical position relative to the sample, and

capture a second microwave response along the path at the second vertical position based on the microwave excitation; and

an impedance detection unit, coupled to the probe, configured to:

generate a first channel voltage based on the first microwave response, and

generate a second channel voltage based on the second microwave response for determining a voltage difference between the first channel voltage based on the first vertical position and the second channel voltage based on the second vertical position for characterizing the sample.

2 . The measurement system as claimed in claim 1 wherein the probe is configured to:

capture the first microwave response relative to a first location along the path based on the microwave excitation; and

capture the second microwave response relative to a second location along the path based on the microwave excitation for determining the voltage difference between the first channel voltage and the second channel voltage based on the first location and the second location corresponding to a lateral location along the path within a lateral tolerance.

3 . The measurement system as claimed in claim 1 wherein:

the excitation unit is configured to generate the microwave excitation at a constant microwave frequency, a constant microwave power, or a combination thereof; and

the probe is configured to:

scan the sample along the path at the first vertical position relative to the sample based on the microwave excitation at the constant microwave frequency, the constant microwave power, or a combination thereof, and

scan the sample along the path at the second vertical position relative to the sample based on the microwave excitation at the constant microwave frequency, the constant microwave power, or a combination thereof.

4 . The measurement system as claimed in claim 1 wherein the impedance detection unit is configured to:

generate the first channel voltage by generating a first direct-current (DC) voltage based on the first microwave response; and

generate the second channel voltage by generating a second direct-current (DC) voltage based on the second microwave response for determining the voltage difference between the first DC voltage based on the first vertical position and the second DC voltage based on the second vertical position for characterizing the sample.

5 . The measurement system as claimed in claim 1 wherein the impedance detection unit is configured to:

generate the first channel voltage by generating a first alternating-current (AC) voltage based on the first microwave response; and

generate the second channel voltage by generating a second alternating-current (AC) voltage based on the second microwave response for determining the voltage difference between the first AC voltage based on the first vertical position and the second AC voltage based on the second vertical position for characterizing the sample.

6 . The measurement system as claimed in claim 1 wherein the probe is configured to:

capture the first microwave response in an approach portion of a z-modulation cycle in an atomic force microscope (AFM) off-resonance tapping mode; and

capture the second microwave response in a retract portion of the z-modulation cycle in the AFM off-resonance tapping mode.

7 . The measurement system as claimed in claim 1 wherein the probe is configured to capture, with a conductive cantilever, the first microwave response along the path at the first vertical position based on the microwave excitation, where the conductive cantilever is shielded, partially shielded, or non-shielded for determining the voltage difference between the first channel voltage based on the first vertical position and the second channel voltage based on the second vertical position in an AFM probe mode with the conductive cantilever.

8 . A method of operation of a measurement system comprising:

generating a microwave excitation towards a sample;

scanning the sample along a path at a first vertical position relative to the sample;

capturing a first microwave response along the path at the first vertical position based on the microwave excitation;

generating a first channel voltage based on the first microwave response;

scanning the sample along the path at a second vertical position relative to the sample;

capturing a second microwave response along the path at the second vertical position based on the microwave excitation;

generating a second channel voltage based on the second microwave response; and

determining a voltage difference between the first channel voltage based on the first vertical position and the second channel voltage based on the second vertical position for characterizing the sample.

9 . The method as claimed in claim 8 wherein:

capturing the first microwave response includes capturing the first microwave response relative to a first location along the path based on the microwave excitation;

capturing the second microwave response includes capturing the second microwave response relative to a second location along the path based on the microwave excitation; and

determining the voltage difference includes determining the voltage difference between the first channel voltage and the second channel voltage based on the first location and the second location corresponding to a lateral location along the path within a lateral tolerance.

10 . The method as claimed in claim 8 wherein:

generating the microwave excitation includes generating the microwave excitation at a constant microwave frequency, a constant microwave power, or a combination thereof;

scanning the sample along the path at the first vertical position includes scanning the sample along the path at the first vertical position relative to the sample based on the microwave excitation at the constant microwave frequency, the constant microwave power, or a combination thereof; and

scanning the sample along the path at the second vertical position includes scanning the sample along the path at the second vertical position relative to the sample based on the microwave excitation at the constant microwave frequency, the constant microwave power, or a combination thereof.

11 . The method as claimed in claim 8 wherein:

generating the first channel voltage includes generating a first direct-current (DC) voltage based on the first microwave response;

generating the second channel voltage includes generating a second direct-current (DC) voltage based on the second microwave response; and

determining the voltage difference includes determining the voltage difference between the first DC voltage based on the first vertical position and the second DC voltage based on the second vertical position for characterizing the sample.

12 . The method as claimed in claim 8 wherein:

generating the first channel voltage includes generating a first alternating-current (AC) voltage based on the first microwave response;

generating the second channel voltage includes generating a second alternating-current (AC) voltage based on the second microwave response; and

determining the voltage difference includes determining the voltage difference between the first AC voltage based on the first vertical position and the second AC voltage based on the second vertical position for characterizing the sample.

13 . The method as claimed in claim 8 wherein:

capturing the first microwave response includes capturing the first microwave response in an approach portion of a z-modulation cycle in an atomic force microscope (AFM) off-resonance tapping mode; and

capturing the second microwave response includes capturing the second microwave response in a retract portion of the z-modulation cycle in the AFM off-resonance tapping mode.

14 . The method as claimed in claim 8 wherein:

capturing the first microwave response includes capturing, with a conductive cantilever, the first microwave response along the path at the first vertical position based on the microwave excitation, where the conductive cantilever is shielded, partially shielded, or non-shielded; and

determining the voltage difference includes determining the voltage difference between the first channel voltage based on the first vertical position and the second channel voltage based on the second vertical position in an AFM probe mode with the conductive cantilever.

15 . A non-transitory computer-readable medium storing an instruction that, when executed by a control circuit of a measurement system, causes the control circuit to perform functions comprising:

generating a microwave excitation towards a sample;

scanning the sample along a path at a first vertical position relative to the sample;

capturing a first microwave response along the path at the first vertical position based on the microwave excitation;

generating a first channel voltage based on the first microwave response;

scanning the sample along the path at a second vertical position relative to the sample;

capturing a second microwave response along the path at the second vertical position based on the microwave excitation;

generating a second channel voltage based on the second microwave response; and

determining a voltage difference between the first channel voltage based on the first vertical position and the second channel voltage based on the second vertical position for characterizing the sample.

16 . The non-transitory computer-readable medium as claimed in claim 15 wherein:

capturing the first microwave response includes capturing the first microwave response relative to a first location along the path based on the microwave excitation;

capturing the second microwave response includes capturing the second microwave response relative to a second location along the path based on the microwave excitation; and

determining the voltage difference includes determining the voltage difference between the first channel voltage and the second channel voltage based on the first location and the second location corresponding to a lateral location along the path within a lateral tolerance.

17 . The non-transitory computer-readable medium as claimed in claim 15 wherein:

generating the microwave excitation includes generating the microwave excitation at a constant microwave frequency, a constant microwave power, or a combination thereof;

scanning the sample along the path at the first vertical position includes scanning the sample along the path at the first vertical position relative to the sample based on the microwave excitation at the constant microwave frequency, the constant microwave power, or a combination thereof; and

scanning the sample along the path at the second vertical position includes scanning the sample along the path at the second vertical position relative to the sample based on the microwave excitation at the constant microwave frequency, the constant microwave power, or a combination thereof.

18 . The non-transitory computer-readable medium as claimed in claim 15 wherein:

generating the first channel voltage includes generating a first direct-current (DC) voltage based on the first microwave response;

generating the second channel voltage includes generating a second direct-current (DC) voltage based on the second microwave response; and

determining the voltage difference includes determining the voltage difference between the first DC voltage based on the first vertical position and the second DC voltage based on the second vertical position for characterizing the sample.

19 . The non-transitory computer-readable medium as claimed in claim 15 wherein:

generating the first channel voltage includes generating a first alternating-current (AC) voltage based on the first microwave response;

generating the second channel voltage includes generating a second alternating-current (AC) voltage based on the second microwave response; and

determining the voltage difference includes determining the voltage difference between the first AC voltage based on the first vertical position and the second AC voltage based on the second vertical position for characterizing the sample.

20 . The non-transitory computer-readable medium as claimed in claim 15 wherein:

capturing the first microwave response includes capturing the first microwave response in an approach portion of a z-modulation cycle in an atomic force microscope (AFM) off-resonance tapping mode; and

capturing the second microwave response includes capturing the second microwave response in a retract portion of the z-modulation cycle in the AFM off-resonance tapping mode.

References Cited (21)

Cited By (1)

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