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arXiv · 2412.05729

Constant di/dz Scanning Tunneling Microscopy: Atomic Precision Imaging and Hydrogen Depassivation Lithography on a Si(100) - 2 x 1 : H Surface

Richa Mishra·S. O. Reza Moheimani
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Abstract

We introduce a novel control mode for Scanning Tunneling Microscopy (STM) that leverages di/dz feedback. By superimposing a high-frequency sinusoidal modulation on the control signal, we extract the amplitude of the resulting tunneling current to obtain a di/dz measurement as the tip is scanned over the surface. A feedback control loop is then closed to maintain a constant di/dz, enhancing the sensitivity of the tip to subtle surface variations throughout a scan. This approach offers distinct advantages over conventional constant-current imaging. We demonstrate the effectiveness of this technique through high-resolution imaging and lithographic experiments on several Si(100)-2x1:H surfaces. Our findings, validated across multiple STM systems and imaging conditions, pave the way for a new paradigm in STM control, imaging, and lithography.

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Richa Mishra, S. O. Reza Moheimani. 2024-12-07. Constant di/dz Scanning Tunneling Microscopy: Atomic Precision Imaging and Hydrogen Depassivation Lithography on a Si(100) - 2 x 1 : H Surface. https://arxiv.org/abs/2412.05729

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