基于LabVIEW的光耦低频噪声成分估计研究

半导体的噪声成分估计是利用噪声进行器件可靠性筛选的前提条件。为此,组建了一套基于虚拟仪器的半导体噪声测试系统,在应用该系统对大量的光电耦合器件（OCD）进行测试基础上,提出了采用LabVIEW对实测噪声功率谱进行噪声成分估计及参数拟合的新方法。该方法的特点是不需要被测器件低频噪声的先验知识,为改进OCD及其他半导体器件的生产工艺和提高器件的可靠性提供了指导性的数据。     

A New Method for RTS Noise of Semiconductor Devices Identification

In this paper, a new method, called the noise scattering pattern method (NSP method), for random telegraph signal noise identification in the inherent noise of semiconductor devices is described. A block diagram of a noise measurement system based on the NSP method is presented. Examples of patterns of the NSP method are included.     

Automatic semiconductor parameter analyzers

An automatic semiconductor parameter analyzer based on an IBM AT personal computer is described. The results of measurements are used to compile banks of mathematical models of various semiconductor devices (bipolar and field-effect transistors, junction and Zener diodes) for use in circuit simulating programs such as PSpice. Translated from Izmeritel'naya Tekhnika, No. 9, pp. 31–34, September 1998.     

Electrical characterization of semiconductor materials and devices—review

Semiconductor materials and devices continue to occupy a pre-eminent technological position because of their importance in building integrated electronic systems for wide ranging applications from computers, cell-phones, personal digital assistants, digital cameras and electronic entertainment systems, to electronic instrumentation for medical diagnostics and environmental monitoring. A key ingredient of this technological dominance has been the rapid advances in the quality and processing of materials—semiconductors, conductors and insulators—thus providing the complementary metal-oxide-semiconductor device technology with its important characteristics of negligible standby power dissipation, good input–output isolation, surface potential control and reliable operation. However, in assessing the material quality and device reliability, it is important to have non-destructive, accurate and easy-to-use electrical characterization techniques available, so that important parameters such as carrier doping density, type and mobility of carriers, interface quality, oxide trap density, semiconductor bulk defect density, contact and other parasitic resistances and oxide electrical integrity can be rapidly determined. This article describes some of the more widely used and popular techniques that are used to determine these important parameters. The techniques presented in this paper range in complexity and requirements for test structures. It ranges from the simple current–voltage measurements, to the more sophisticated low-frequency noise and deep-level transient spectroscopy techniques.     

Hybrid organic on inorganic semiconductor heterojunction

Hybrid organic on inorganic semiconductor heterojunctions with a sandwich structure have been fabricated and studied using conjugated polymers. The inorganic semiconductor was n-type silicon substrate. The conjugated polymers used include poly(2-methoxy-5-(2-ethylhexyloxy)-1,4-phenylenevinylene) containing polyhedral oligomeric silsesquioxanes (MEH-PPV POSS), regioregular poly(3-hexylthiophene) (RR-P3HT) and poly(3,4-ethylenedioxythiophene) (PEDOT). Current density–voltage and capacitance–voltage measurements were performed. All of the devices displayed a rectifying characteristic. Among these devices, the first ever reported PEDOT doped with BF₃ on n-Si heterojunction devices showed the best performance with a rectification ratio around 5.7 × 10⁵ at ± 2 V and an ideality factor of 2.3. The results showed better device performance with decreased potential barrier height at the organic–inorganic interface. Results also suggested that smaller energy level offset between the HOMO of the conjugated polymer and the work function of anode metal will improve device performance.     

Present trends and realisations in readout electronics for semiconductor detectors in high energy physics

Design criteria of signal processors for semiconductor detectors in high energy physics experiments are reviewed.Choice of input active devices of preamplifiers, detector-device capacitive matching, preamplifier configurations, variant and invariant signal processors are discussed.Several examples of processors for microstrip silicon detectors and for silicon detector telescopes, are reviewed with particular emphasis on noise performance and high rate capabilities.     

Effect of electrostatic discharge on semiconductor devices and subsequent annealing of electrostatic defects

The effect of electrostatic discharge on semiconductor devices and of subsequent annealing of electrostatic defects by electrical loading and (or) at high temperatures is discussed. The effect of electrostatic discharge has been described in terms of the human body phantom. Translated from Izmeritel’anaya Tekhnika, No. 1, pp. 45–46, January, 1998.     

Strain oriented microstructural change during the fabrication of free-standing PbSe micro-rods

In this work, we are reporting fabrication of micro-rods based on epitaxially grown lead selenide (PbSe) on (111) oriented barium fluoride (BaF₂). The micro-rods were formed by folding back action of PbSe and their dimension was determined by the initial layer thickness and etching parameters. The micro-rods scattered throughout the surface were measured to have diameters mainly in the range of ∼14–18 μm and lengths ∼40–300 μm. These robust micro-rods can be used for future research on semiconductor microstructures and mid infrared opto-electronic devices.     

On the possibility of eliminating the energy threshold for electron detection in semiconductor detectors

A method of eliminating the energy threshold for electron detection in semiconductor devices is described. The class of devices used for the detection and measurement of electron emission is sufficiently large, including electrostatic analyzers, gas-filled devices, microchannel plates, etc. An alternative to these types of devices for electron detection is offered by semiconductor radiation detectors based on the p-n junctions, which are widely used in the spectrometry of nuclear particles including medium-and high-energy electrons (10² keV and above). These detectors are obviously advantageous in comparison to the devices of other types, but there are several factors hindering the use of semiconductor detectors for the detection and analysis of low-energy electrons (in the kiloelectronvolt range). We propose an approach that allows the energy threshold for electron detection in semiconductor detectors to be eliminated by means of preliminary acceleration of the detected particles in an electrostatic field created between the emitter and the detector. This approach removes the basic factor limiting the use of semiconductor detectors in a number of diagnostic methods based on the analysis of electron emission, such as the extended X-ray absorption fine structure (EXAFS), surface EXAFS, and X-ray absorption near-edge structure (XANES) techniques.     

Efficient optical packet-generation and -compression scheme

An efficient optical packet-generation and -compression scheme is proposed. Packet compression is achieved when the packet is sent through a series of semiconductor optical amplifiers, which have either a transmitting or an absorbing state. The proposed scheme requires no fast electronics and uses exceptionally simple devices such as a tapped series of D flip-flops and frequency dividers. A detailed performance analysis on the system size limitations is also provided by the consideration of pulse-spreading effects and semiconductor optical-amplifier noise.     

Synthesis of multilayered composite nanotube heterostructure; SiC–SiO2, C–SiO2, and C–SiC–SiO2 nanotubes

Three types of composite nanotube heterostructures (two double-layered and one triple-layered structure) are synthesized by simple heat treatment, forming SiC–SiO₂, C–SiO₂, and C–SiC–SiO₂ composite coaxial nanotubes. These multilayered composite nanotubes consist of several components with different electrical properties, for example, metal, semiconductor, and insulator components. In particular, C–SiC–SiO₂ triple-layered nanotubes with metallic, semiconducting, and insulating layers are synthesized for the first time. These multilayered nanotubes can be expected to find applications in nanoscale heterostructure electronic and optical devices.     

The influences of technological conditions and Au cluster islands on morphology of Ga<Subscript>2</Subscript>O<Subscript>3</Subscript> nanowires grown by VLS method on GaAs substrate

The synthesis of semiconductor nanowires is more and more interested to the applications for building blocks of the innovative nano-sized devices and circuits, but the research and fabrication of these nanowires are also holding a number of difficulties and challenges. Among many different kinds of semiconductor nanowires, Ga₂O₃ is increasingly grown for many promising applications in nano-device production, namely nanowire LED and Laser. So far there are many synthesizing methods of semiconductor nanowires, among them the vapor–liquid–solid (VLS) method is simple, cheap and popular. However, when we use the VLS method for nanowire growth, various technological problems exist. This paper aims at investigating some influences of the growth technological conditions and Au metal catalyst on the morphology of Ga₂O₃ nanowire grown by VLS on GaAs substrate. The main considering factors include the different growing temperatures and times, the effects of Au diffusion, Au droplets formation, Au cluster islands formation, and gas volume of the growing tube/ampoule at the 10⁻¹ torr low air pressure. The obtained experimental results regarding the structural properties of nanowires under these effects investigated by scanning electron microscopy, field emission scanning electron microscopy, high angle annular dark field and bright field, scanning transmission electron microscopy, energy-dispersive X-ray techniques, and focus ion beam are presented and discussed.     

Electrical characteristics and inhomogeneous barrier analysis of aniline green/p-Si heterojunctions

In this study, we identically prepared the aniline green/p-Si organic–inorganic devices (total 27 diodes) formed by direct evaporation of an organic compound solution on to a p-Si semiconductor wafer, and then studied the current–voltage (I–V) and capacitance–voltage (C–V) characteristics of these devices. It was seen that the aniline green organic thin film on the p-Si substrate showed a good rectifying behavior. The barrier heights (BHs) and ideality factors of all devices were extracted from the electrical characteristics. Mean BH and ideality factor were calculated as 0.582 eV and 2.999, respectively from the I–V characteristics. Additionally, the mean barrier height and mean acceptor doping concentration from C–V measurements were calculated as (0.61 ± 0.10) eV and (5.54 ± 0.68) × 10¹⁴ cm⁻³, respectively. The discrepancy in the BH values obtained from I–V and C–V characteristics has been attributed to different nature of the measurements. This can also be due to the existence of the interfacial native oxide and the organic aniline green thin layer between the semiconductor and contacting top metal.     

Ferromagnetism of ZnO and GaN: A Review

The observation of ferromagnetism in magnetic ion doped II–VI diluted magnetic semiconductors (DMSs) and oxides, and later in (Ga,Mn)As materials has inspired a great deal of research interest in a field dubbed “spintronics” of late, which could pave the way to exploit spin in addition to charge in semiconductor devices. The main challenge for practical application of the DMS materials is the attainment of a Curie temperature at or preferably above room temperature to be compatible with junction temperatures. Among the studies of transition-metal doped conventional III–V and II–VI semiconductors, transition-metal-doped ZnO and GaN became the most extensively studied topical materials since the prediction by Dietl et al., based on mean field theory, as promising candidates to realize a diluted magnetic material with Curie temperature above room temperature. The underlying assumptions, however, such as transition metal concentrations in excess of 5% and hole concentrations of about 10²⁰ cm⁻³, have not gotten as much attention. The particular predictions are predicated on the assumption that hole mediated exchange interaction is responsible for magnetic ordering. Among the additional advantages of ZnO-and GaN-based DMSs are that they can be readily incorporated in the existing semiconductor heterostructure systems, where a number of optical and electronic devices have been realized, thus allowing the exploration of the underlying physics and applications based on previously unavailable combinations of quantum structures and magnetism in semiconductors. This review focuses primarily on the recent progress in the theoretical and experimental studies of ZnO- and GaN-based DMSs. One of the desirable outcomes is to obtain carrier mediated magnetism, so that the magnetic properties can be manipulated by charge control, for example through external electrical voltage. We shall first describe the basic theories forwarded for the mechanisms producing ferromagnetic behavior in DMS materials, and then review the theoretical results dealing with ZnO and GaN. The rest of the review is devoted to the structural, optical, and magnetic properties of ZnO- and GaN-based DMS materials reported in the literature. A critical review of the question concerning the origin of ferromagnetism in diluted magnetic semiconductors is given. In a similar vein, limitations and problems for identifying novel ferromagnetic DMS are briefly discussed, followed by challenges and a few examples of potential devices.     

Computer-aided system for measuring the static parameters of semiconductor devices

A computer-aided system for measuring the static parameters of semiconductor devices is described. The system is controlled by a personal computer. A hierarchy of models is formed from the results of the measurements from the simplest behavioral models to the accurate physical models used in computer-aided design systems. Translated from Izmeritel'naya Tekhnika, No. 12, pp. 49–52, December, 1996.     

Characterizing the Superconducting-to-Normal Transition in Mo/Au Transition-Edge Sensor Bilayers

We are developing arrays of Mo/Au bilayer transition-edge sensors (TES’s) for future X-ray astronomy missions such as NASA’s Constellation-X. The physical properties of the superconducting-to-normal transition in our TES bilayers, while often reproducible and characterized, are not well understood. The addition of normal metal features on top of the bilayer are found to change the shape and temperature of the transition, and they typically reduce the unexplained ‘excess’ noise. In order to understand and potentially optimize the properties of the transition, we have been studying the temperature, widths and current dependence of these transitions. We report on the characterization of devices both deposited on silicon substrates and suspended on thin silicon nitride membranes. This includes key device parameters such as the logarithmic resistance sensitivity with temperature α, and the logarithmic resistance sensitivity with current β, and their correlation with excess noise.      

Experimental unit for measuring angular oscillation in precision roller bearings

A unit is described for measuring the play of the precision spindles of instruments such as theodolites. The unit differs from similar devices not only in its high sensitivity (0.01 μm), but also in the fact that the readings of the counter are not influenced by external fields. It is found that the coordinates u of displacements can potentially be measured with a high degree of accuracy by using coordinate-sensitive photodetectors and semiconductor lasers. Angular positioning is measured with a minimum error of ±0.06°. Translated from Izmeritel'naya Tekhnika, No. 7, pp. 29–31, July, 1996.     

In-band noise suppression using novel monolithically integrated semiconductor optical amplifier-based ultra-compact interferometers

Novel all-optical noise suppressors based on the nonlinear transfer function properties of monolithically integrated active waveguide interferometers are proposed and demonstrated. Through a power map imbalance between the two arms of the interferometers, each of which contains multi-contact semiconductor optical amplifiers, a nonlinear transfer function is created, which can then be exploited to achieve in-band noise suppression. The authors demonstrate the use of such a mechanism in ultra-compact Mach-Zehnder and Michelson interferometers (MIs). Experimental work demonstrates a 5.0-dB optical signal-to-noise ratio improvement for the Mach-Zehnder and an 8.4-dB improvement for the MIs, respectively. It is shown that for input data the Mach-Zehnder is capable of providing a Q factor improvement of 4.1 dB. To the authors knowledge, these devices constitute the smallest integrated interferometer structures reported to date demonstrating in-band noise suppression.