Charging effects in Si quantum dots for Non Volatile Memories applications monitored by Electrostatic Force Microscopy

2003 ◽  
Vol 794 ◽  
Author(s):  
R.A. Puglisi ◽  
G. Nicotra ◽  
S. Lombardo ◽  
C. Spinella ◽  
G. Ammendola ◽  
...  
Keyword(s):  
Silicon Oxide ◽  
Electrostatic Force ◽  
Chemical Vapour ◽  
Nanoscale Structures ◽  
Force Microscopy ◽  
Si Nanocrystals ◽  
Potential Applications ◽  
P Type ◽  
Mos Structures ◽  
Si Quantum Dots

ABSTRACTNanoscale structures have been recently proposed as charge storage nodes due to their potential applications for future nanoscale memory devices. Our approach is based on the idea of using Si nanodots as discrete floating gates. To experimentally investigate such potential, we have fabricated MOS structures with Si nanocrystals. The dots have been deposited onto an ultra-thin tunnel oxide by chemical vapour deposition, and then annealed at 1000 °C for 40 s, to crystallize all the dots. After deposition the dots have been covered by a CVD SiO2 layer, thus resulting in dots completely embedded in stoichiometric silicon oxide. The nanocrystal density and size have been studied by energy filtered TEM (EFTEM) analysis. An electrostatic force microscope has been used to locally inject the charge. By applying a relatively large tip voltage a few dots have been charged, and the shift in the tip phase has been monitored. The shift in the phase is attributed to the presence of the charge in the sample. A comparison between n and p type samples is also shown.

scholarly journals Quantitative phase‐mode electrostatic force microscopy on silicon oxide nanostructures

2020 ◽  
Vol 280 (3) ◽  
pp. 252-269
Author(s):  
C. ALBONETTI ◽  
S. CHIODINI ◽  
P. ANNIBALE ◽  
P. STOLIAR ◽  
R. V. MARTINEZ ◽  
...  
Keyword(s):  
Silicon Oxide ◽  
Electrostatic Force ◽  
Electrostatic Force Microscopy ◽  
Force Microscopy ◽  
Quantitative Phase ◽  
Oxide Nanostructures

scholarly journals Nanofriction characteristics of h-BN with electric field induced electrostatic interaction

Friction ◽  
2020 ◽  
Author(s):  
Kemeng Yu ◽  
Kun Zou ◽  
Haojie Lang ◽  
Yitian Peng
Keyword(s):  
Electric Field ◽  
Electrostatic Interaction ◽  
Hexagonal Boron Nitride ◽  
Electrostatic Force ◽  
Solid Lubricants ◽  
Conductive Atomic Force Microscopy ◽  
Force Microscopy ◽  
Atomic Force ◽  
Graphene Devices ◽  
P Type

AbstractThe nanofriction properties of hexagonal boron nitride (h-BN) are vital for its application as a substrate for graphene devices and solid lubricants in micro- and nano-electromechanical devices. In this work, the nanofriction characteristics of h-BN on Si/SiO2 substrates with a bias voltage are explored using a conductive atomic force microscopy (AFM) tip sliding on the h-BN surface under different substrate bias voltages. The results show that the nanofriction on h-BN increases with an increase in the applied bias difference (Vt−s) between the conductive tip and the substrate. The nanofriction under negative Vt−s is larger than that under positive Vt−s. The variation in nanofriction is relevant to the electrostatic interaction caused by the charging effect. The electrostatic force between opposite charges localized on the conductive tip and at the SiO2/Si interface increases with an increase in Vt−s. Owing to the characteristics of p-type silicon, a positive Vt−s will first cause depletion of majority carriers, which results in a difference of nanofriction under positive and negative Vt−s. Our findings provide an approach for manipulating the nanofriction of 2D insulating material surfaces through an applied electric field, and are helpful for designing a substrate for graphene devices.

Fabrication of SiNWs-FET Nanostructure Via Atomic Force Microscopy Lithography

2020 ◽  
Vol 301 ◽  
pp. 103-110
Author(s):  
Nurain Najihah Alias ◽  
Khatijah Aisha Yaacob ◽  
Kuan Yew Cheong
Keyword(s):  
Atomic Force Microscopy ◽  
Relative Humidity ◽  
Silicon Nanowires ◽  
Silicon Oxide ◽  
Silicon Layer ◽  
Silicon On Insulator ◽  
Force Microscopy ◽  
Atomic Force ◽  
Effect Transistor ◽  
P Type

The unique electrical properties of silicon nanowires (SiNWs) is one of the reasons it become an attractive transducer for biosensor nowadays. Positive (holes) and negative (electron) charge carriers from SiNWs can simply interact with either positive or negative charge of sensing target. In this paper, we have studied the fabrication of silicon nanowires field effect transistor (SiNWs-FET) nanostructure patterned on 15 Ω resistivity of p-type silicon on insulator (SOI) wafer fabricated via atomic force microscopy lithography technique. To fabricate SiNWs-FET nanostructure, a conductive AFM tip, Cr/Pt cantilever tip, was used then various value of applied voltage, writing speed and relative humidity were studied. Subsequent, followed by wet etching processes, admixture of tetramethylammonium hydroxide (TMAH) and isopropyl alcohol (IPA) were used to remove the undesired of silicon layer and diluted hydrofluoric acid (HF) was used to remove the oxide layer. From the results, it shows that, cantilever tip at 9 V with 0.4 μm/s writing speed and relative humidity between 55% - 60% gives the best formation of silicon oxide to fabricate SiNWs-FET nanostructure.

Quantitative Charge Imaging of Silicon Nanocrystals by Atomic Force Microscopy

2002 ◽  
Vol 737 ◽  
Author(s):  
Tao Feng ◽  
Harry A. Atwater
Keyword(s):  
Atomic Force Microscopy ◽  
Nonvolatile Memory ◽  
Electrostatic Force ◽  
Contact Mode ◽  
Force Microscopy ◽  
Atomic Force ◽  
Si Nanocrystals ◽  
Nonvolatile Memory Devices ◽  
Quantitative Understanding ◽  
Simulated Images

ABSTRACTQuantitative understanding of charging and discharging of Si nanocrystals in SiO2 films on Si substrate is essential to their application in floating gate nonvolatile memory devices. Charge imaging by atomic force microscopy (AFM) or electrostatic force microscopy (EFM) can provide qualitative information on such system, while a further step is needed. We have developed a generalized method of images, which can solve Poisson equation for multiple dielectric layers, to simulate the charge imaging of Si nanocrystals by non-contact mode AFM under different sample geometries. Simulated images can be compared with experimental images thoroughly to estimate the total amount and distributions of trapped charges, which is also useful in the study of time evolution of charges or dissipation problems.

Imaging of stored charges in Si quantum dots by tapping and electrostatic force microscopy

2002 ◽  
Vol 59 (4) ◽  
pp. 566-571 ◽  
Author(s):  
C Guillemot ◽  
P Budau ◽  
J Chevrier ◽  
F Marchi ◽  
F Comin ◽  
...  
Keyword(s):  
Quantum Dots ◽  
Electrostatic Force ◽  
Electrostatic Force Microscopy ◽  
Force Microscopy ◽  
Si Quantum Dots

scholarly journals Sizing single nanoscale objects from polarization forces

2019 ◽  
Vol 9 (1) ◽  
Author(s):  
H. Lozano ◽  
R. Millán-Solsona ◽  
R. Fabregas ◽  
G. Gomila
Keyword(s):  
Silver Nanowires ◽  
Electrostatic Force ◽  
Electric Polarization ◽  
Scanning Probe ◽  
Force Microscopy ◽  
Wide Range ◽  
Potential Applications ◽  
Nanoscale Object ◽  
Topographic Imaging ◽  
Microscopic Techniques

Abstract Sizing natural or engineered single nanoscale objects is fundamental in many areas of science and technology. To achieve it several advanced microscopic techniques have been developed, mostly based on electron and scanning probe microscopies. Still for soft and poorly adhered samples the existing techniques face important challenges. Here, we propose an alternative method to size single nanoscale objects based on the measurement of its electric polarization. The method is based on Electrostatic Force Microscopy measurements combined with a specifically designed multiparameter quantification algorithm, which gives the physical dimensions (height and width) of the nanoscale object. The proposed method is validated with ~50 nm diameter silver nanowires, and successfully applied to ~10 nm diameter bacterial polar flagella, an example of soft and poorly adhered nanoscale object. We show that an accuracy comparable to AFM topographic imaging can be achieved. The main advantage of the proposed method is that, being based on the measurement of long-range polarization forces, it can be applied without contacting the sample, what is key when considering poorly adhered and soft nanoscale objects. Potential applications of the proposed method to a wide range of nanoscale objects relevant in Material, Life Sciences and Nanomedicine is envisaged.

Spatial separation mechanism in Si quantum dots deposited by chemical vapour deposition on SiO2

2003 ◽  
Vol 788 ◽  
Author(s):  
Rosaria A. Puglisi ◽  
Giuseppe Nicotra ◽  
Salvatore Lombardo ◽  
Corrado Spinella ◽  
Cosimo Gerardi
Keyword(s):  
Silicon Oxide ◽  
Chemical Vapour ◽  
Spatial Separation ◽  
Separation Mechanism ◽  
Transmission Electron ◽  
Oxide Substrates ◽  
Average Size ◽  
New Si ◽  
Region Size ◽  
Si Quantum Dots

ABSTRACTA systematic study on the Si inter-dot distance after nucleation on silicon oxide substrates is presented. The process has been followed from the very early stages of the dot formation up to 25% of coverages. Structural characterization has been performed by means of energy filtered transmission electron microscopy, which allowed us to observe dot sizes down to 0.5 nm in radius. Silicon nanodots are shown to be surrounded by a depleted zone, where no new Si dots are observed to nucleate. The average size of such a zone ranges between 4 and 9 nm, depending on the deposition conditions. The dot radius is shown to be proportional to the depleted region size, thus indicating the scaling behaviour of the process.

Optical Band Gaps and Electrical Conductance of Si Nanocrystals in SiO2 Matrix for Optoelectronic Applications

2013 ◽  
Vol 545 ◽  
pp. 134-140 ◽  
Author(s):  
Thipwan Fangsuwannarak ◽  
K. Khunchana ◽  
S.T. Rattanachan
Keyword(s):  
Silicon Oxide ◽  
Energy Gap ◽  
Electrical Conductance ◽  
Oxide Phase ◽  
Considerable Effect ◽  
Density Level ◽  
Optical Energy Gap ◽  
Force Microscopy ◽  
Tauc Plot ◽  
Si Nanocrystals

In this study, silicon nanocrystal (Si-nc) films were synthesized by compositing of Si-nc powder embedded in silicon oxide phase. The Si-nc film produced by the spin-coating methode using Tetraethylorthosilicate, ethanol, phosphoric acid, and Si-nc powder as suspension precursors. The variation in structural and optical properties of Si-nc sol films with the amounts of Si-nc powder have been characterized. Atomic force microscopy (AFM) shows that low density level of Si-nc power can result in the amount of porosity in the Si-nc films. It is found that when the Si-nc films have the higher Si-nc density, the small pores in the SiO2 phase were removed. In addition, optical energy gap (Eg) of Si-nc samples was evaluated by the Tauc plot method. It is a crucial attribute for a promising photonic device. The obtained optical bang gap values were extended from 1.10 eV to 1.40 eV as compared with the typical Si bulk. In addition, density of Si-nc clusters has a considerable effect on the electrical conductance of the Si-nc films measured at room temperature.

Enhancements of Non-contact Measurements of Electrical Waveforms on the Proximity of a Signal Surface Using Groups of Pulses

2002 ◽  
Author(s):  
Fenglei Du ◽  
Greg Bridges ◽  
D.J. Thomson ◽  
Rama R. Goruganthu ◽  
Shawn McBride ◽  
...  
Keyword(s):  
Integrated Circuits ◽  
Integrated Circuit ◽  
Signal To Noise Ratio ◽  
Electrostatic Force ◽  
Single Pulse ◽  
Electric Signal ◽  
Measurement Instruments ◽  
Cycle Times ◽  
Force Microscopy ◽  
And Performance

Abstract With the ever-increasing density and performance of integrated circuits, non-invasive, accurate, and high spatial and temporal resolution electric signal measurement instruments hold the key to performing successful diagnostics and failure analysis. Sampled electrostatic force microscopy (EFM) has the potential for such applications. It provides a noninvasive approach to measuring high frequency internal integrated circuit signals. Previous EFMs operate using a repetitive single-pulse sampling approach and are inherently subject to the signal-to-noise ratio (SNR) problems when test pattern duty cycle times become large. In this paper we present an innovative technique that uses groups of pulses to improve the SNR of sampled EFM systems. The approach can easily provide more than an order-ofmagnitude improvement to the SNR. The details of the approach are presented.

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