Johnson-noise-limited cancellation-free microwave impedance microscopy with monolithic silicon cantilever probes

Jun-Yi Shan; Nathaniel Morrison; Su-Di Chen; Feng Wang; Eric Y Ma

doi:10.1038/s41467-024-49405-8

Johnson-noise-limited cancellation-free microwave impedance microscopy with monolithic silicon cantilever probes

Nat Commun. 2024 Jun 13;15(1):5043. doi: 10.1038/s41467-024-49405-8.

Authors

Jun-Yi Shan^{1

2}, Nathaniel Morrison^{1

2}, Su-Di Chen^{1

2

3}, Feng Wang^{1

2

3}, Eric Y Ma^{4

5

6}

Affiliations

¹ Department of Physics, University of California, Berkeley, Berkeley, CA, 94720, USA.
² Lawrence Berkeley National Laboratory, Berkeley, CA, 94720, USA.
³ Kavli Energy NanoScience Institute, University of California, Berkeley, Berkeley, CA, 94720, USA.
⁴ Department of Physics, University of California, Berkeley, Berkeley, CA, 94720, USA. eric.y.ma@berkeley.edu.
⁵ Lawrence Berkeley National Laboratory, Berkeley, CA, 94720, USA. eric.y.ma@berkeley.edu.
⁶ Department of Electrical Engineering and Computer Sciences, University of California, Berkeley, Berkeley, CA, 94720, USA. eric.y.ma@berkeley.edu.

Abstract

Microwave impedance microscopy (MIM) is an emerging scanning probe technique for nanoscale complex permittivity mapping and has made significant impacts in diverse fields. To date, the most significant hurdles that limit its widespread use are the requirements of specialized microwave probes and high-precision cancellation circuits. Here, we show that forgoing both elements not only is feasible but also enhances performance. Using monolithic silicon cantilever probes and a cancellation-free architecture, we demonstrate Johnson-noise-limited, drift-free MIM operation with 15 nm spatial resolution, minimal topography crosstalk, and an unprecedented sensitivity of 0.26 zF/√Hz. We accomplish this by taking advantage of the high mechanical resonant frequency and spatial resolution of silicon probes, the inherent common-mode phase noise rejection of self-referenced homodyne detection, and the exceptional stability of the streamlined architecture. Our approach makes MIM drastically more accessible and paves the way for advanced operation modes as well as integration with complementary techniques.

Abstract

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