Search query: nonlinear dielectric and capacitance

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abstract: The time resolved measurement of capacitance is a powerful method in the evaluation of defects in semiconductors, carrier dynamics in quantum dots, and photo induced dynamics in photovoltaic materials. In this study, we demonstrate time resolved capacitance measurements at the nanoscale using scanning nonlinear dielectric microscopy. We detected the capacitance transient of SiO2/4H SiC interfaces triggered by the application of a 3 ns pulse, showing the high temporal resolution of the developed method. We exemplified the method with the evaluation of the density and activation energy of defects at SiO2/4H SiC interfaces that verified the quantitative capability and high sensitivity of the method. Two dimensional mapping of the interface states showed nanoscale inhomogeneous contrasts, implying that the physical origin of the defects at SiO2/4H SiC interfaces is microscopically clustered.
author_names: Yuji Yamagishi

Yasuo Cho
title: Nanosecond microscopy of capacitance at SiO2/4H SiC interfaces by time resolved scanning nonlinear dielectric microscopy
year: 2017

abstract: Noncontact scanning nonlinear dielectric microscopy (NC SNDM) is a microwave based scanning probe microscopy method detecting the variation in the tip sample capacitance. By detecting the second order nonlinear effect in dielectric polarization, this method enables imaging spontaneous polarization in materials. Although dielectric polarization is a material property formulated in a somewhat macroscopic sense, a series of the measurement results on cleaned semiconductor surfaces suggest that atomic scale polarization, or atomic dipoles, can be resolved by NC SNDM. Here we review unique capability of this method and mention its significance in solid state and surface physics. We also explain a novel extension of NC SNDM, called noncontact scanning nonlinear dielectric potentiometry (NC SNDP) and its application to the nanoscale evaluation of two dimensional materials. The results reviewed here show that these methods will be tools for the atomic scale investigation of surface and interface charge states even in a quantitative way.
author_names: K Yamasue

Yasuo Cho
title: Atomic Resolution Studies on Surface Dipoles by Noncontact Scanning Nonlinear Dielectric Microscopy and Potentiometry
venue: 2020 Joint Conference of the IEEE International Frequency Control Symposium and International Symposium on Applications of Ferroelectrics (IFCS ISAF)
year: 2020

abstract: Scanning nonlinear dielectric microscopy (SNDM) can be used to visualize the carrier distribution in semiconductors with high sensitivity and spatial resolution. We recently proposed a complementary method named C/z SNDM that avoids the problem of contrast reversal. This paper describes a methodology for calculating the signal intensity in C/z SNDM using examples. For the simulation, the capacitance of a conductive probe metal/oxide/semiconductor model was calculated and then the response signal for various probe sample distances was analyzed. The simulation results confirm that the C/z SNDM signal intensity increases monotonically with dopant concentration, avoiding contrast reversal. Moreover, in addition to the fundamental (1o) signal, higher harmonic (2o, 3o) signals have sufficient intensities to be detected. The results suggest that the detection sensitivity for low dopant concentrations can be improved by conducting the measurement under an appropriate dc bias.
author_names: Yoshiomi Hiranaga

Yasuo Cho
title: Carrier distribution imaging using C/z mode scanning nonlinear dielectric microscopy.
venue: The Review of scientific instruments
year: 2019

abstract: We discuss the feasibility of interface defect density estimation using scanning nonlinear dielectric microscopy (SNDM) With reference to the previous results on SiO2/SiC gate stacks, we evaluate the non uniformity in the microscopy images of SiO2/Si and high k/SiO2/Si gate stacks. The results suggest that a high k layer on a SiO2/Si gate stack has little impact on the quality of interface. Our procedure possibly gives a useful method for the nanoscale evaluation of interface quality at gate stacks with Si substrates. We also measure local capacitance voltage (CV) spectrum by newly developed time resolved SNDM, which show CV spectrum gradually changed during the measurement.
author_names: Koharu Suzuki

K Yamasue

Yasuo Cho
title: A Study on Evaluation of Interface Defect Density on High K/SiO2/Si and SiO2/Si Gate Stacks using Scanning Nonlinear Dielectric Microscopy
venue: 2019 IEEE International Integrated Reliability Workshop (IIRW)
year: 2019

abstract: Abstract The effect of Nb5+ on the crystallographic structure, electrical properties and the dielectric behaviour of Na 0.5 La 0.5 Cu 3 Ti 4 x Nb x O 12 ceramics prepared via the solid state reaction method were investigated. Rietveld refinement of the powder diffraction data confirmed a cubic, single phase structure with space group Im3. A low frequency Debye type relaxation is observed for the Nb doped samples in addition to the usually observed high frequency relaxation. The grain boundary resistance decreased significantly with increasing Nb5+ dopant. The reduced grain boundary resistivity was found to be responsible for the decrease in the potential barrier at the grain boundary as observed from the overall variation of current density electric field (J E) characteristics. The dielectric constant at low Frequency is increased with increasing Nb content. The dielectric behaviour of the compound is explained on the basis of the Internal Barrier Layer Capacitance (IBLC) model.
author_names: and K George Thomas

Merin K George

D Sajan

Kevin Abraham

Jini Thomas

K V Saban
title: Effect of niobium doping on the dielectric and nonlinear current voltage characteristics of Na0.5La0.5Cu3Ti4O12 ceramics
venue: Optical Materials
year: 2019

abstract: [Shi Yan toJie Guo nXing SiCJi Ban noSiMian ni20 nmnoRe Suan Hua Mo gaXing Cheng saretaShi Liao woPing Jia Dui Xiang toshiteYong ita. NOFen Wei Qi Xia dePOAChu Li saretaShi Liao toPOAChu Li nosareteinaiShi Liao noEr Zhong Lei noShi Liao niDui shiteSNDMCe Ding woXing tsuta. ma zuBian Diao Xin Hao noZhou Bo Shu wo1 MHz, Shi Liao niYin Jia surubaiasuDian Ya ha0 Vtoshite|dC/dV|Xiang woQu De shita. konoShi Qu De sa reta|dC/dV|Xiang woTu 1(a)toTu 1(b)nisorezoreShi su. Zou Cha Ling Yu noMian Nei deha|dC/dV|gaKong Jian De niBu Jun Yi niFen Bu shiteori, Te ni POA Chu Li sareteinaiShi Liao dehaMian Nei denoRong Liang Te Xing nobaratsukigaDa kiikotogaFen karu. Ci niTu 1(a)Nei noChi Xian toTu 1(b)Nei noQing Xian deShi shitaXian Shang deCe Ding sareta, |dC/dV|toBan Dao Ti Ceng henoYin Jia baiasunoGuan Xi woTu 1(c)niShi su. |dC/dV|nopikugaQue Ren dekiruga, konouchi POA Chu Li sareteinaiShi Liao dehapikunoZui Da Zhi |dC/dV|max)gaXiang Dui De niXiao saku, matapikunoBan Zhi Quan Fu (FWHM)haDa kii. korehaPOAChu Li sareteinaiShi Liao noJie Mian Zhun Wei Mi Du gaXiang Dui De niGao ku, Jin Shu Tan Zhen /Suan Hua Mo /Ban Dao Ti deGou Cheng sareruMOSGou Zao noC VTe Xing ga"stretch out"shiteirukotoni Dui Ying surutoKao erareru. saraniTu 1(b)noXian Fen ABShang niokeru|dC/dV|maxtoFWHMnoFen Bu woTu 1(d)niShi su. Xiang Dui De ni|dC/dV|maxgaDa kikuFWHMgaXiao saiLing Yu (i)to, sonoNi noQing Xiang woShi suLing Yu (ii)gaCun Zai shiteirukotogaQue Ren deki ruga, koreranoLing Yu hasorezoreJie Mian Zhun Wei Mi Du gaDi iLing Yu toGao iLing Yu niDui Ying shiteirutoKao erare, Jie Mian Zhun Wei Mi Du gaMian Nei deBu Jun Yi niFen Bu shiteirukotogaShi Suo sareru. [Xie Ci Ben Yan Jiu haSIP (Zhan Lue De inobeshiyonChuang Zao puroguramu)/Ci Shi Dai pawaerekutorokusuniyotsuteShi Shi sareta. [Can Kao Wen Xian [1] Y. Cho, A. Kirihara, T. Saeki, Rev. Sci. Instrum. 67 (1996) 2297
author_names: Yuji Yamagishi

N Chinone

Yasuo Cho
title: Evaluation of Local Capacitance Characteristics of SiO 2 /4H SiC Interface by Scanning Nonlinear Dielectric Microscopy
year: 2016

abstract: Outer hair cell (OHC) nonlinear capacitance (NLC) represents voltage sensor charge movements of prestin (SLC26a5) the protein responsible for OHC electromotility. Previous measures of NLC frequency response have employed methods which did not assess the influence of dielectric loss (sensor charge movements out of phase with voltage) that may occur, and such loss conceivably may influence prestin's frequency dependent activity. Here we evaluate prestin's complex capacitance out to 30 kHz and find that prestin's frequency response determined using this approach coincides with all previous estimates. We also show that membrane tension has no effect on prestin's frequency response, despite substantial shifts in its voltage operating range, indicating that prestin transition rate alterations do not account for the shifts. The magnitude roll off of prestin activity across frequency surpasses the reductions of NLC caused by salicylate treatments that are known to abolish cochlear amplification. Such roll off likely limits the effectiveness of prestin in contributing to cochlear amplification at the very high acoustic frequencies processed by some mammals.
author_names: Joseph Santos-Sacchi

Winston J T Tan
title: Complex nonlinear capacitance in outer hair cell macro patches: effects of membrane tension
venue: Scientific Reports
year: 2020

abstract: In this paper, the cracking fault occurred in the dynamic environment of the multi layer porcelain dielectric capacity used in a aerospace electronic product. The stress and deformation response in the PCB area where the multi layer porcelain dielectric capacity is located are reduced by a reasonable PCB layout. Damping materials are added to PCB to reduce vibration. The nonlinear damping characteristics of material damping and energy filtering are used to realize energy consumption in the area of multi layer porcelain dielectric capacity on PCB.
author_names: Zhang Yu

Liu Mi
title: Research on reliability Optimization design of multilayer porcelain dielectric capacitance of aerospace electronic products based on dynamic simulation
venue: 2020 7th International Forum on Electrical Engineering and Automation (IFEEA)
year: 2020

abstract: We demonstrate that scanning nonlinear dielectric microscopy (SNDM) can be used for the nanoscale characterization of dominant carrier distribution on atomically thin MoS2 mechanically exfoliated on SiO2. For stable imaging without damaging microscopy tips and samples, SNDM was combined with peak force tapping mode atomic force microscopy. The identification of dominant carriers and their spatial distribution becomes possible even for single and few layer MoS2 on SiO2 using the proposed method allowing differential capacitance (dC/dV) imaging. We can expect that SNDM can also be applied to the evaluation of other two dimensional semiconductors and devices.We demonstrate that scanning nonlinear dielectric microscopy (SNDM) can be used for the nanoscale characterization of dominant carrier distribution on atomically thin MoS2 mechanically exfoliated on SiO2. For stable imaging without damaging microscopy tips and samples, SNDM was combined with peak force tapping mode atomic force microscopy. The identification of dominant carriers and their spatial distribution becomes possible even for single and few layer MoS2 on SiO2 using the proposed method allowing differential capacitance (dC/dV) imaging. We can expect that SNDM can also be applied to the evaluation of other two dimensional semiconductors and devices.
author_names: K Yamasue

Yasuo Cho
title: Local carrier distribution imaging on few layer MoS2 exfoliated on SiO2 by scanning nonlinear dielectric microscopy
year: 2018

abstract: A nanoscale linear permittivity imaging method based on scanning nonlinear dielectric microscopy (SNDM) was developed. The C/z mode SNDM (C/z SNDM) technique described herein employs probe height modulation to suppress disturbances originating from stray capacitance and to improve measurement stability. This method allows local permittivity distributions to be examined with extremely low noise levels (approximately 0.01 aF) by virtue of the highly sensitive probe. A cross section of a multilayer oxide film was visualized using C/z SNDM as a demonstration, and numerical simulations of the response signals were conducted to gain additional insights. The experimental signal intensities were found to be in a good agreement with the theoretical values, with the exception of the background components, demonstrating that absolute sample permittivity values could be determined. The signal profiles near the boundaries between different dielectrics were calculated using various vibration amplitudes and the boundary transition widths were obtained. The beneficial aspects of higher harmonic response imaging are discussed herein, taking into account assessments of spatial resolution and quantitation.
author_names: Yoshiomi Hiranaga

N Chinone

Yasuo Cho
title: Nanoscale linear permittivity imaging based on scanning nonlinear dielectric microscopy.
venue: Nanotechnology
year: 2018