The evolution of microelectronics to nanoelectronics is discussed based on the device figure of merit( power delay product), while an overview of their current development situation is given. In the same time, it is indicated that in the course of SOC ( system on a chip) development the introduction of new, much powerful than the conventional, information processing system is inevitable. Finally, some expectations of the main differences between microelectronics and nanoelectronics are given.
There are beauties in the nanoscale world. Artistic patterns in nanoscale thin films are formed as a result of phase transformations. There are only a few combined materials that can produce artistic patterns in a nanoscale thin film for ultrahigh density information storage. The patterns produced by far-from-Equilibrium self-organization growth can be divided into three categories, i. e. , growth with demarcating synergetic atomic or molecular diffusion, growth with demarcating nonsynergetic atomic diffusion, and growth with non-demarcating synergetic atomic diffusion. Three pictures for each category will be shown as representatives. These patterns can not be produced as repeatable growth. An additional example as the repeatable growth will also be given.
In the last decade of the 20th century, a brand-new field of nano scale science and technology has emerged in the World. The fundamental and applications of nano scale science and technolgy are intrOduced. The applications of nanotechnology Which include uantum function devices, film sensors, nanodisplay, nanometer scale materials, micrOelectrOmechanical systems ( MEMS , nanobiological technology and atomic engineering, etc. are prospected. Some e perimental results are given.
People are now endeavoring to develop nanoelectronic devices to the third generation of electron devices. Compared With their two predecessors vacuum electronic devices and microelectronic devices, the newly emerging nanoelectronic devices have such principal distinguishing characteristics as: ( 1) single-electron behaviors, ( 2) phase retaining, ( 3) quantum resistance (h /e2), ( 4) quantum bit (qubit) and ( 5) universal conductance fluctuation. The essential elements ofan electronic device are triodes with the capability of signal amplification. At present two types of nanoelectronic triode amplifiers, namely nanodot triode and carbon nanotube triode, have been proposed. The structures and properties of carbon-based nano-materials which are used for the constraction of future nanoelectronic triodes are discussed.
Molecular electronics is a developing direction for microelectronics. The developing history, main achievements taken place in recent years, key problems and future trend are introduced briefly.
ReSearch advance about molecular assembly and its application in fabrication of nanostructures and devices is systematically summarized. In addition, research, which is proceeded at the Center for Nano-Scale Science and Technology in Southeast University, in this field is introduced. The main work includes fabrication of electrodes with nanogap based on the combination of molecular self-assembly and photolithography, preperation of ordered two-dimensional metal nanoparticle arrays, fabrication and simulation of Single-electron devices, and preparation of core-shell composite materials by Using molecular assembly.
In the framework of the effective mass envelop function theory, we got the amiltonian of the quantum ellipsoid after a coordinate transition. The energies wave functions are calculated as functions of the aspect ratio. With an overall consideration of the transition matrix element and the Boltzmann distribution, we explained why the polarization factor increases with increasing e and approaches a saturation value which tallies quite well with the experiment reported. The effects of the crystal field splitting energy temperature and transverse radius to the polarization are also considered. We discussed the band gap variation with the size and shape of the quantum ellipsoid at last.
By means of modified rate Equations We inVestigate the influence of the transVerse interdot coupling on the AharonoV-Bohm ( AB) structure, Which is composed of two coupled quantum dots ( GDs) sandWiched betWeen source and drain. The numerical results show that the interdot coupling betWeen the two GDs can cause a temporal oscillation in electronoccupation at the initial stage of the quantum dynamics, While the source-drain current decays monotonically to a stationary Value. On the other hand, the interdot coupling diVides the AB ring into two coupled subrings. That destroys the normal AB oscillation and generates a new and complex periodic oscillation With its period related to the magnetic flux ratio.
A solid-state quantum computer scheme Using electron-nucleon double spins is proposed. The addressing of gubit, single gubit operation and the control-not gate between any two gubits are realized by Using an STM tip. The technique involved in this scheme is either current available or very close to the present technical expectation. Thus the scheme may be realized Using existing technologies.
For researching on the thermal characteristics of silicon nitride thin membrane such as heat capacity, radiation, convection, and so on, a kind of floating membrane is designed. And thermal transfer mechanism of the floating membrane is analyzed. Si3N4 floating membranes with different areas and thicknesses are fabricated by Using micro-fabrication techniques, and their several thermal parameters of them are obtained from experiments.
Photoluminescence ( PLD and electrolumineScence (ELD properties of strained self-assembled InAS/GaAS quantum dots ( GDSD structure grown by molecular-beam epitaxy technique are presented. A comparative analysis is made of optical characteristics for laSer diodes emitting at 1. 08pm With InAS/GaAS GDS in the active region. The maximum CW output of 2. 74W ( two facets and internal quantum efficiency of 87% are achieved at room temperature in 100pm Wide Strips and 1. 6mm cavity length laser diode with uncoated facets.
Initial nucleation stage of 2D Ge islands during the self-assembled groWth of Ge islands in Si/Ge mismatch system is studied by Kinetic Monte Carlo ( KMC) simulation. The diffusion barrier is corrected by introducing a strain field induced by adsorbed atoms. The influence of stain and substrate temperature on nucleation sites and size is investigated. The nucleation of 2D islands is determined by strain field and the self-assembled growth can be controlled by modulating the stain on the surface.
A microcavity prepared by PE VD is proposed. Its distributed Bragg ref1ectors are composed of periodica11y stacked a-SiO2 = H/ a-Si= H 1ayers and the active 1ayer is filled With a-Si I= H. The structure ofa microcavity is determined through simu1ating. In eXperiment, a microcavity is prepared at 250 and annea1ed at different temperatures. Ref1ectance and Pl spectra are recorded on as-deposited and annea1ed samp1es. It is indicated that the as-deposited samp1e performs We11 and even better after annea1ed at 350 , however Worse after annea1ed at 450 .
Al/Al203 multilayers with nanometer scale are fabricated by thermal evaporation and natural oxidization techniques. The detection of X-ray and photoelectron spectroscopy (XPS) and ultraviolet photoelectron spectroscopy (UPS) is performed, and the curve ofei (ki ) is got. The properties of the negative resistance for the multilayers are found.
The nanoindention physical model ofatomic force microscopy between its tip and sample surface is established. The nanoindention adhesive force eXpression is obtained based on Hamaker hypothesizes and Lennard-Jones potential function by the continuous method. The Hamaker constant approXimate formula is established based on the principle of Lif shitz, followed by the Hamaker constant ofau, Cu, Al, Ag. The result is in agreement with experiments.
The 5nm Pt films are deposited on p-Si (111) substrate by magnetron sputtering. After annealing, Pt films turn into PtSi. The characteristic of surface and interface of Ptsi films are studied by AFM and -RTEM. The results show that the technology conditions influence the interface structure and surface morphology of Ptsi films. With an increase of substrate temperature, the columnar clusters on the surface become into the flat ones, and multi-layer films to be the single ones. If the substrate are heated, there are only PtSi phase in the single layer film that is uniform and sound and has a smooth, clear and coherent interface.
The self-assembled InGaAs/GaAs quantum dots superlattices for 8 ~ 12pm infrared photodetector working at atmospheric window are grown by MBE. It is demonstrated that the intersublevel absorption wavelength of InGaAs/GaAs quantum dot superlattices can be ad usted by varying the shape and size of quantum dots and the thickness of InGaAs layer. It is observed that as the thickness of InGaAs layer increased the infrared absorption peak blue-shifts from 15 to 10pm. The changes can be attributed to the enhanced effect of coupling between quantum dots.
The surfactant-mediated solution method is employed to synthesize nano-scale magnesium hydroxide. The poWder products have the sizes of diameter 3 ~ 6nm and length 50 ~ 100nm for needle-like nanoparticles. The photoluminescence intensity of Mg( O~) 2 nanocrystallites increases rapidly With decrease of the size of particle. Mg( O~) 2 /Ethylene-vinyl-acetate ( 1= 1) nanocomposite is also prepared. Its value of the limiting oxygen index (LOI) is 38. 3. The high-resolution transmission electron microscope images show that the Mg( O~) 2 nanopaticles disperse homogenously in EVA matrix.
The preparations of silica antireflective coating on glass by sol-gel process and RF sputtering process are discussed and compared. The effects of sol concentration, aging and annealing on antireflectivity are investigated. While the sol concentration is 0.4M, aging time is 6 days and annealing temperature is 450℃, the transmittance of the coated glass can reach up to 99.3%. The structure of sol and gel is studied Using IR spectroscopy, and it is found that the Si-O-Si bonds were strengthened after aging and annealing.
Nanometer thin film strain resistance is manufactured directly on the metallic elastic substrate by ion-beam sputtering technology and semiconductor micro-machining technology, Which achieve atomic union betWeen sensitive element and elastic substrate. This effectively solves the technical problem about Nzero drift H of the traditional pressure sensors, and makes pressure sensors be stable and reliable for long-term on condition of harsh environment, such as high temperature and vibration and so on.
Anatase TiO2 thin films on glass substrates are obtained in an aqueous solution of ( N~4 ) 2TiF6 and ~3BO3 supersaturated With nano-crystalline TiO2 . Transparent anatase TiO2 thin films is obtained at 35 When the concentration of TiF2-6 in the aqueous solution is 0. 1mol /L , and the TiF2-6 /~3BO3 molar ratio is 1= 2~ 4. The film thickness increases with deposition time. The film thickness is 260nm at a deposition time of 9h. AFM micrographs of films calcined at various temperatures are all smooth and uniform. The FTIR spectra of the as-deposited film shows that the TiO2 film has formed the Ti-O-Si bond With the glass. Photocatalytic actiVity of the TiO2 thin films is eValuated by methylene blue degradation. The TiO2 thin films prepared by calcination at 300 show the highest photocatalytic actiVity, Which is 5 times of the actiVity of the films prepared by deposition at 35 .
The effect of different amount of TiO2 and thermal-treatment on the fabrication of nanocrystalline spinel glassceramics from the Li2O-MgO-Al2O3 -SiO2 system With the aid of DSC XRD and SEM is analysed. Nucleating mechanism is also discussed to find that enough TiO2 content ( no less than 7~ 5% D is the key to obtain nanocrystalline. Experiment results show that glass-ceramics with uniformly dispersed spinel crystals about 80nm in size can be produced when TiO2 content is 10% and such glass are heat-treated under appropriate conditions. The result glass-ceramics are suitable for substrates of high-performance hard-disk according to the characteristic test.
A method of thin film etching and the relevant Equipment are introduced. A way of fabricating large-area suspending ultra-thin films (thickness of them, 50~ 500nm, 1~ 5Mm; area of them, 3mm × 2mm, 10mm × 5mm) with metal electrodes is provided. Rate of finished products will increase by 30 per cent. The equipment has many advantages such as simple structure, small volume, light weight, low cost, easy to process, convenient to operate, and is capable of design and manufacture its form according to the need of devices.
Nano-cholesteryl liguid crystal material is synthesized by condensation polymerization. Changing the chiral components content and chiral temperature and ad usting the intermolecular nano-pitch lead the polymer to different optical and spectrum behaviour. The sample is synthesized, which has even surface. Its colour changes with the incident ray angle and observation situation. The eXperiments show that the material has an potential application in the field of printing, adornment, false proofand so on.
Nanocrystalline tin oxide transparent conducting thin films are prepared by the method of the direct current magnetron sputtering in a mixture gas ofar and O2 , and at substrate temperature 150~ 400C . The films show preferred orientation in [110] and [211] plane by X-ray diffraction. The crystalline properties of nanocrystalline SnO2 Sb thin films depends on the substrate temperature. The surface and section morphology are obtained at loW and high substrate temperature by FE-SEM.
Characterization and surface modification of electric property are carried out on the organmetallic compleX AgTCNG thin film by scanning tunneling microscope ( STM). The resistance ofan organmetallic complex Ag-TCNG thin film Will be changed from a high resistance state to a loW resistance state When the bias voltage between the tip of STM and the bottom electrode is in excess ofa certain threshold voltage. The two states can be defined as S07 and S17 of a memory unit, respectiVely. Change of electric property is recorded in the conventional mode of STM. In order to avoid the effect of tunneling junction, which is not the intrinsic property of the material, betWeen the tip and the sample, a test in so-called Scontact7 mode of STM is carried out, and the result is compared with that in the conVentional mode.
A new nanomaterial has the novel electrical bistable effects. This organic thin film is applied to excite the tapered slot antennas9and the nanomaterial makes the operation of the antennas more security and save the energy, which is applied in the micrometer and millimeter measurements. It is the first time to utilize the nanomaterial in the antennas structure. The finite difference time domain ( FDTD) was used in this paper to analyze the important performances of the tapered slot antennas ( TSA) , which applied the novel nanomaterial as the feeding material. The measured results are in good agreement with the calculation ones, which verifies the validity of the calculating program.
Pt particles With size ofapproximate 6 ~ 8nm are prepared by the method of microemulsion reaction. Through controlling suitable conditions such as deposited temperature of Pt particles, pressed pressure of carrier and heated treat process of catalysts, Pt/C/PTFE nano-hydrophobic catalyst are prepared. In the hydrogen isotope gas-liguid exchange process, its catalystic actiVities are tested. The results show that the catalystic actiVities data Kya of nanohydrophobic is high one times than that of Pt/C/PTFE by the immersion method.
P-type double-barrier quantum well resonant tunnelling diodes is realiZed by ultra high vacuum epitaxy tool GS400. A peak to valley current ratio of 1. 13 and a peak current density of 1. 589kA/cm2 at room temperature ( 293K D from continuous dc current-voltage measurements are recorded while at 77K With pulsed current-voltage measurements the corresponding values are 1. 24 and 1. 086kA/cm2 . The loW PVCR in both cases are attributed to the energy band features and thermal effects of Si1-IGeI/Si heterostructures.
The Non-Equilibrium-Green's-Function ( NEGFD based model of resonant tunneling diode ( RTDD is studied. By calculating the distribution ofelectron densities inside the devices Using the NEGF method I-V characteristics of the RTD is depicted. A AlGaAs/GaAs/AlGaAs sandwiched RTD structure is the chosen as the ob ect of the calculation. By varying parameters comparison is made to explicate the influence of the width of the barrier and well. The correctness of the results are explained theoretically and compared with a analytical model based on Wigner function.
Using a P8510( C) network analyzer, the scattering parameter ( S22 ) Of AlAs/ InGaAs/AlAs resonant tunneling diodes (RTD) is measured. Equivalent circuit parameters are obtained by curve fit. The RTD switching time is estimated by Using the measured capacitance and aVerage negatiVe differential resistance. The minimum rise time of the sample is estimated to be 21ps.
The characteristics of mutil-gate MOSFET ( double gates and trible gates FINFET) are simulated systemically by Using 3D simulation prsgram ISE. The I-V characteristics are investigated. The results show that the performances of Tri gate MOSFET are generally superior to ones of double gate's. However, With the decreasing of the FIN's width, double gate's performances trend to Tri gatre's.
The performance of sub 50nm double gate MOSFET with different channel-length is simulated by the hydrodynamic simulation software developed. The distribution of electron temperature and drift velocity is compared in the channel direction. The short channel effect is also analyzed.
A novel scheme for incorporating quantum effect in classical hydrodynamic model is proposed. No additional Equations are needed to solve quantum potential with this scheme, so the complexity ofEquations is largely reduced. Based on this, a HD simulation program is developed. The 25nm gate length MOSFET and 30nm FinFET are simulated.
20~ 50nm CMOS device structure and the key technologies are investigated. By these innovations of technologies, high performance 42nm gate length CMOS devices and 48nm gate 1ength CMOS ring oscillators are fabricated successfully. At supply power voltage VDD of 1. 5V, the drive current lon of 42nm gate length CMOS are 745pA/pm for NMOS and 530pA/pm for PMOS at off-state leakage loff of 3. 5 nA/pm for NMOS and 15pA/pm for PMOS. The Sub-threshold slope of 72mV/ Dec and DIBL of 34mV/V for NMOS and Sub-thresho1d S1ope of 82mV/Dec and DIBL of 57mV/V for PMOS are obtained. 48nm gate length 57 Stage CMOS ring oscillator exhibits per-stage delay of 19. 9ps at 1. 5V.
The screen-prinring merhod of fabricarion fie1d emission carhode( FEC) Wirh poWder carbon naonrubes( CNTs) is reporred. Afrer annea1ing and hydrogen p1asma surface rrearmenr, e1ecrron fie1d emission properries of rhese CNT carhodes are obVious1y increased. The resu1rs show rhar rhe rhresho1d fie1d decreases form 4V/ pm ro 1V/ pm; e1ecrron emission currenr densiry is 2. 53mA/ cm2 ar an e1ecrric fie1d of 4. 5V/ pm; emission sire densiry dramarica11y increases form 103 / cm2 ro 105 / cm2 . Based on rhose achieVemenrs, rhe rhree-color carbon nanorube fie1d emission 1ighr prororype Wirh rriode-rype srrucrure is successfu11y designed and packaged.
Carbon nanotube has its advantages as a cathode material for field emission. Good adhesion between the carbon nanotubes and the substrate is obtained by thermal treatment. Testing curves are obtained by measuring the properties of field emission . In addition, the experimental results are analysed, and methods for improving uniformity of the carbon nanotubes are reported.
Metal particle modulated car on nanotu e devices are fa ricated Using the conventional lithography and nanotechnologies, and their field effect and single electron characteristics are measured for varying temperatures.
A calculation method for the value of planar inductor is presented. The effects that determine the merit of planar spiral inductor are analyzed. Based on an electrical model of the micromachined inductor, eddy current effect induced parasitic resistance and the capacitance due to the lossy substrate are carefully studied. The obtained theoretical result shows the value is related to both the inductor geometric size and the operating frequency. An optimized planar inductor can be realized through the theoretical analysis and calculation.
Based on the analysis to the traditional parallel-plate capacitor We present a novel MEMS tunable capacitor with a wide tuning range. Different from the conventional parallel-plate capacitors this capacitor consists of three pairs of plates. One pair of them is used as capacitor plates and the other two are used as controlling plates. AC signal passes through the capacitor plates while DC controlling voltage is applied between the controlling plates. By simulation with Ansys softWare We get the tuning range is up to 214% largely beyond the theoretical tuning range limit ( 50% D of conventional two-parallel-plate capacitors. It can be easily integrated in RF circuits for this simple process of fabrication.
A novel sensor used in pCT(micro-computed tomography) is studied. Mathematical methods for follow the tracks ofenergy and geometry are used as signal processing while imaging, accounting for problem of center of brightness With circle eXisted in linear array scanning by means ofarea array CCD to be used as sensor in pCT. This new sensor has such some properties as high space resolution, structure of flexibility, high efficiency with light transmitted and light coupled, etc. This new sensor can be applied in micro-computed tomography.
A new technology for the fabrication of silicon condenser microphones is presented. The technology is based on the use of porous silicon as sacrificial layer for the acoustic holes and the polyimide diaphragm for the acoustic membrane. The microphone with an open-circuit sensitivity of -107. 8dB and a flatter frequency response between 400Hz and 10kHz has been fabricated with this technology. The microphone can be used for acoustic communication.
The nanocrystalline silicon films ( nc-Si= D by PECVD method possess a series of novel properties. With the nc-Si = film depositiod on the opposite type of single silicon ( c-SiD wafers nc-Si/ c-Si heterojunclion diodes are fabricated. It is found there are a lot of unique features which are no exist in common silicon diodes. The possibility of other silicon devices fabricated by nc-Si= films such as Schottky diodes TFT transistors and so on is discussed.
A novel material porous silicon is used as diffusion layer in pPEMFC (micro proton eXchange membrane fuel cells) for its loose and porous structure and compatibility with IC process. Study of the formation of porous silicon and metal sputter deposition on the porous silicon is performed. A fabrication process of pPEMFC based on the technology of MEMS and film deposition is presented.
A new magnetic sensor utiliZing the magneto-impedance effect in nanocrystalline materials is developed, which has advantageous features in high sensitivity, temperature stability, and long operation life comparing with conventional magnetic sensors such as Flux-Gate magnetometer, ~all devices, magneto-resistance sensors. They have generated successful applications in car speed measuring, engine s time ignition and other industy control system etal.
A simulator based on orthodox theory and Monte Carlo method is depicted. The simulator is suitable for a kind of quantum device-- single electron transistors (SET). It simulates the propagation of electrons through a network consisting of quantum tunnel junctions, capacitors and ideal voltage sources. The simulation of the SET which is comprised of coulomb single island and multi-islands are done using the simulator.
Recent progress in organic electroluminescence diSplay technology has led to a new stage of the research of organic Semiconductors. Application in electroluminescence displays photovoltaic devices thin film transistors solar cells and memory units will spur the development of the organic electronic industry.
Effect on luminance-homogeneity of projection screen by the fineness of SiO2 nano-particle is studied. The results show that With the decrease of the fineness of SiO2 , luminance-homogeneity can be improVed. Finally the reasons are discussed from the nano-structure point of VieW and the scattering principle.
Effect on optical properties of projection screen by fine carbon powder is studied. The results show that with the additiVe of microcrystalline graphite and fishbone-like carbon tube, luminance of projection screen can not be fallen; furthermore, luminance and luminance-homogeneity of projection screen which is added with fishbone-like carbon tube are better. Finally, the possible reasons are discussed from the additiVe structure and the scattering principle.
The electron scattering processes are simulated by Monte Carlo method. The production mechanism of proximity effect and effective approaches of proximity effect correction are inVestigated. The experimental results show that proximity effect is a comprehensive phenomenon. It can be reduced and expectant purpose of proximity effect correction can be achieved through optimizing processes.
Electron beam lithography (EBL) is a specialized technique for creating the extremely fine patterns by the modern electronics industry for integrated circuits. In this research, the main attention is focused on the technology of positive resistPMMA and chemically amplified negative resist-SAL6O1. The nano-level patterns are exposed by the above resists. E-beam/optical mix and match lithography is employed to improve the efficiency ofe-beam lithography. Both resize the pattern and dose modulation are devised to minimize the proximity effect.
two classes of nanoscale fabrication techniques, including high-resolution techniques and process induced techniques, are introduced. High-resolution techniques, as the extension of microelectronics lithography, include the efficient but expensive Extreme Ultraviolet lithography, the very efficient and low-cost, immature nano-imprint lithography, and the fine but low-output Scanning Probe lithography. Process induced techniques use some routinely used process and principle, such as sidewall, anisotropic etching and porous anodic aluminum oxide template to form local or self-assemble well-controlled nanostructure. Although the nanostructure is beyond the resolution of photolithography used in process, the integrated density is restricted by photolithography.