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Figure from:Dissipation modulated Kelvin probe force microscopy method

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Fig. 1.9 (a) Topography and (b) dissipation images of a CCD image sensor with FM mode with no ac voltage and a constant Vpias = 50 mV applied. Af = —0.3 Hz. No contrast is observed in (b). (c) dissipation image with coherent ac voltage with FM mode with its amplitude, Vac = 100 mMVp_—p (wel = Wm). The similar contrast to that appears in the topography (a) is observed. (e) topography, (f) dissipation, (g) potential images with lwD-KPFM technique with Vac = 100 mVp—p, Wel = wm.

Figure 1 9 (a) Topography and (b) dissipation images of a CCD image sensor with FM mode with no ac voltage and a constant Vpias = 50 mV applied. Af = —0.3 Hz. No contrast is observed in (b). (c) dissipation image with coherent ac voltage with FM mode with its amplitude, Vac = 100 mMVp_—p (wel = Wm). The similar contrast to that appears in the topography (a) is observed. (e) topography, (f) dissipation, (g) potential images with lwD-KPFM technique with Vac = 100 mVp—p, Wel = wm.

Related Figures (12)

Fig. 1.1 Block diagram of dissipation modulated Kelvin probe force microscopy technique proposed by Fukuma et al. [10]. The induced dissipation is detected by measuring the change in the amplitude of tip oscillation. Reprinted from [10], with the permission of AIP Publishing
Fig. 1.1 Block diagram of dissipation modulated Kelvin probe force microscopy technique proposed by Fukuma et al. [10]. The induced dissipation is detected by measuring the change in the amplitude of tip oscillation. Reprinted from [10], with the permission of AIP Publishing
Yoichi Miyahara and Peter Grutter Fig. 1.2 Topography and CPD images of dimethylquinquethiophene monolayer formed on a Pt surface. (a) topography and (b) CPD images taken by FM-KPFM. (c) topography and (d) CPD images taken by DM-KPFM. From [10]. Reprinted from [10], with the permission of AIP Publishing
Yoichi Miyahara and Peter Grutter Fig. 1.2 Topography and CPD images of dimethylquinquethiophene monolayer formed on a Pt surface. (a) topography and (b) CPD images taken by FM-KPFM. (c) topography and (d) CPD images taken by DM-KPFM. From [10]. Reprinted from [10], with the permission of AIP Publishing
Fig. 1.3 (a) Schematic representation of tip position, z, restoring force, —kz, the in- phase fundamental Fourier component, Fin cos(wmt), and the total force. (b) Schematic representation of tip position, z, internal damping force, m7yo2, the quadrature fundamental Fourier component, Fguaa sin(wmt), and the instantaneous power delivered from the tip- sample interaction
Fig. 1.3 (a) Schematic representation of tip position, z, restoring force, —kz, the in- phase fundamental Fourier component, Fin cos(wmt), and the total force. (b) Schematic representation of tip position, z, internal damping force, m7yo2, the quadrature fundamental Fourier component, Fguaa sin(wmt), and the instantaneous power delivered from the tip- sample interaction
where C is the tip-sample capacitance, Vpias and Vepa are the applied dc voltage and the contact potential difference (CPD), and Vac, wei, @ are the amplitude, angular frequency, and phase of the applied ac bias voltage. Va. = Vbias — Vepa is the effective dc bias voltage. It is important to notice that although the three force component terms, Fo, Fy, Fo, are grouped by the frequency of we, harmonic component such as 0, w, 2w, they do not represent the frequency of harmonic components of the actual oscillating electrostatic wt gee. eee
where C is the tip-sample capacitance, Vpias and Vepa are the applied dc voltage and the contact potential difference (CPD), and Vac, wei, @ are the amplitude, angular frequency, and phase of the applied ac bias voltage. Va. = Vbias — Vepa is the effective dc bias voltage. It is important to notice that although the three force component terms, Fo, Fy, Fo, are grouped by the frequency of we, harmonic component such as 0, w, 2w, they do not represent the frequency of harmonic components of the actual oscillating electrostatic wt gee. eee
As we have seen in Sect. 1.2.1, the amplitude of cos(wmt) and sin(wyt) terms, Fi’ and F,4, determine the frequency shift, Af, and dissipation, g, respectively. Here the superscript, lw, refers to the case of we, = wm and thus lwD-KPFM.
As we have seen in Sect. 1.2.1, the amplitude of cos(wmt) and sin(wyt) terms, Fi’ and F,4, determine the frequency shift, Af, and dissipation, g, respectively. Here the superscript, lw, refers to the case of we, = wm and thus lwD-KPFM.
Fig. 1.4 Block diagram of the experimental setup for force sensitive (lwD-KPFM) and force-gradient sensitive (2uD-KPFM) dissipation modulated KPFM techniques. Reprinted from [9], with the permission of AIP Publishing
Fig. 1.4 Block diagram of the experimental setup for force sensitive (lwD-KPFM) and force-gradient sensitive (2uD-KPFM) dissipation modulated KPFM techniques. Reprinted from [9], with the permission of AIP Publishing
Fig. 1.5 Validation of lwD-KPFM theory. (a) Frequency shift, Af, and (b) dissipation signal, g, versus dc bias voltage, Vpias, curves taken with a coherent sinusoidally oscillating voltage with the amplitude, Vac = 100 mVp-—p and various phases, ¢, applied to a 200 nm thick SiO2 on Si substrate. The dissipation signal is normalized with the value without the ac bias voltage (indicated with the horizontal blue dashed line). In both figures, each of dashed lines represent fitted curves assuming a parabola for Af and a linear line for g as indicated in Eq. 1.18 and 1.19, respectively. The oscillation amplitude of the tip was 7.2nmMp—p and the quality factor of the cantilever was 9046. Reprinted with permission from [8]. Copyright 2016 by the American Physical Society
Fig. 1.5 Validation of lwD-KPFM theory. (a) Frequency shift, Af, and (b) dissipation signal, g, versus dc bias voltage, Vpias, curves taken with a coherent sinusoidally oscillating voltage with the amplitude, Vac = 100 mVp-—p and various phases, ¢, applied to a 200 nm thick SiO2 on Si substrate. The dissipation signal is normalized with the value without the ac bias voltage (indicated with the horizontal blue dashed line). In both figures, each of dashed lines represent fitted curves assuming a parabola for Af and a linear line for g as indicated in Eq. 1.18 and 1.19, respectively. The oscillation amplitude of the tip was 7.2nmMp—p and the quality factor of the cantilever was 9046. Reprinted with permission from [8]. Copyright 2016 by the American Physical Society
Fig. 1.6 Parabola maximum of the measured Af-Vijas curves (red circles) (Fig. 1.5(a)) and the dissipation slope of g-Vpias curves (blue circles) (Fig. 1.5(b)). Each solid line represents the fitted curve with the cosine function (Eq. 1.18) for the parabola minimum and with the sine function (Eq. 1.19) for the dissipation slope. The horizontal dashed line indicates the voltage for parabola maximum without the ac bias voltage. Reprinted with permission from [8]. Copyright 2016 by the American Physical Society
Fig. 1.6 Parabola maximum of the measured Af-Vijas curves (red circles) (Fig. 1.5(a)) and the dissipation slope of g-Vpias curves (blue circles) (Fig. 1.5(b)). Each solid line represents the fitted curve with the cosine function (Eq. 1.18) for the parabola minimum and with the sine function (Eq. 1.19) for the dissipation slope. The horizontal dashed line indicates the voltage for parabola maximum without the ac bias voltage. Reprinted with permission from [8]. Copyright 2016 by the American Physical Society
Fig. 1.7 (a) Frequency shift, Af, and (b) dissipation signal, g, versus dc bias voltage. Vbias, Curves taken with a coherent sinusoidally oscillating voltage with wey = 2wm, Vac = 1 V and various ¢, applied to a template stripped gold substrate. The vertical dashed line in (a) and (b) indicates Vepq which is measured as the voltage coordinate of the parabola vertex without Vac. The horizontal dashed line in (b) indicates the dissipation without Vac. In both figures, each of dashed lines represent fitted curves assuming a parabola fo1 Af and a linear line for g as indicated in Eqs. 1.26 and 1.27, respectively. The oscillation amplitude of the tip was 10 nmp—p and the quality factor of the cantilever was 25000
Fig. 1.7 (a) Frequency shift, Af, and (b) dissipation signal, g, versus dc bias voltage. Vbias, Curves taken with a coherent sinusoidally oscillating voltage with wey = 2wm, Vac = 1 V and various ¢, applied to a template stripped gold substrate. The vertical dashed line in (a) and (b) indicates Vepq which is measured as the voltage coordinate of the parabola vertex without Vac. The horizontal dashed line in (b) indicates the dissipation without Vac. In both figures, each of dashed lines represent fitted curves assuming a parabola fo1 Af and a linear line for g as indicated in Eqs. 1.26 and 1.27, respectively. The oscillation amplitude of the tip was 10 nmp—p and the quality factor of the cantilever was 25000
Fig. 1.8 (a) Voltage coordinate of the vertices of the measured Af-Vpias Curves (parabola maximum) (red circles) extracted from the results Fig. 1.7(a) and the slope of dissipation- Vpias Curves (blue triangles) extracted from Fig. 1.7(b) as a function of phase. Each solid line represents the fitted curve with the cosine function (Eq. 1.26) for the parabola maxi- mum and with the sine function (Eq. 1.27) for the dissipation slope. The horizontal dashed line indicates the voltage coordinate of the parabola measured without the ac bias voltage. (b) Af offset as a function of phase. The solid line represents the fitted curve with the second term of Eq. 1.26. Reprinted from [9], with the permission of AIP Publishing
Fig. 1.8 (a) Voltage coordinate of the vertices of the measured Af-Vpias Curves (parabola maximum) (red circles) extracted from the results Fig. 1.7(a) and the slope of dissipation- Vpias Curves (blue triangles) extracted from Fig. 1.7(b) as a function of phase. Each solid line represents the fitted curve with the cosine function (Eq. 1.26) for the parabola maxi- mum and with the sine function (Eq. 1.27) for the dissipation slope. The horizontal dashed line indicates the voltage coordinate of the parabola measured without the ac bias voltage. (b) Af offset as a function of phase. The solid line represents the fitted curve with the second term of Eq. 1.26. Reprinted from [9], with the permission of AIP Publishing
Fig. 1.10 Optical micrograph of the patterned MoS2 flakes exfoliated on SiO2/Si sub- strate.The flake in the circle is the one imaged by the KPFM imaging experiments. Scale bar is 20 pm.
Fig. 1.10 Optical micrograph of the patterned MoS2 flakes exfoliated on SiO2/Si sub- strate.The flake in the circle is the one imaged by the KPFM imaging experiments. Scale bar is 20 pm.
Fig. 1.11 Topography and CPD images of the patterned MoS2 flake. Topography images taken by (a) lwD-KPFM, (b) AM-KPFM, (c) 2uD-KPFM and (d) FM-KPFM techniques. CPD images taken by (e) lwD-KPFM, (f) AM-KPFM, (g) 2vD-KPFM and (h) FM-KPFM techniques. (i) Profiles of the CPD images by (e) lwD-KPFM and (f) AM-KPFM tech- niques. (j) Profiles of the CPD images by (g) 2uD-KPFM and (h) FM-KPFM techniques
Fig. 1.11 Topography and CPD images of the patterned MoS2 flake. Topography images taken by (a) lwD-KPFM, (b) AM-KPFM, (c) 2uD-KPFM and (d) FM-KPFM techniques. CPD images taken by (e) lwD-KPFM, (f) AM-KPFM, (g) 2vD-KPFM and (h) FM-KPFM techniques. (i) Profiles of the CPD images by (e) lwD-KPFM and (f) AM-KPFM tech- niques. (j) Profiles of the CPD images by (g) 2uD-KPFM and (h) FM-KPFM techniques