The study of the charge collection of the normal‐collector configuration

Charge collection is one of the crucial processes to collect the induced current when a semiconductor sample is subjected to some external excitations such as the electron or photon beams. The charge collection probability is the basis in the study of this induced current particularly in the field of photonic devices, photovoltaic cells as well as in the characterization of semiconductor materials and devices. In this paper, the analytical expressions for the charge collection probability of the finite‐dimension normal‐collector configuration, with and without surface recombination at the free surfaces are presented. An excellent agreement has been found between the charge collection probability profiles computed using the presently derived analytical expressions and those obtained using a device simulator. The results have been used to study the effects of the various physical parameters on the charge collection probability. These analytical expressions are expected to enhance our understanding of the charge collection process. Copyright © 2012 John Wiley & Sons, Ltd.     

Ultra‐Smooth and Ultra‐Strong Ion‐Exchanged Glass as Substrates for Organic Electronics

The introduction of new substrate materials into the world of electronics has previously opened up new possibilities for novel applications and device designs. Here, the use of ion‐exchanged sodium aluminosilicate (NAS) glass is presented as a new type of substrate that is not only highly damage resistant, but also allows the fabrication of high performance organic electronic devices. The smoothness of the NAS glass surface enables favorable growth of the semiconductor layer, enabling high charge carrier mobilities for typical organic semiconductors, such as pentacene or C60, and a polymer semiconductor. No degradation of the device performance is observed as a result of ion migration into the active device region, and no compromise in substrate strength due to the processing conditions is made. This work suggests the possibility of new, highly durable electronic devices on glass in large area format.     

The interaction between semiconductors and acoustic surface waves—A review

Recent developments in acoustic surface wave (ASW) device applications are based on a coupling between an ASW and charge carriers in a semiconductor. The problems related to such devices are similar to those encountered in MOS and CCD work since the wave-charged particle interaction occurs within a Debye length of the surface. This paper presents a brief review of ASW-semiconductor devices.     

用EBIC法观察InSb半导体器件中的p-n结

能够直观地\     

Optical Noninvasive Diagnostic of Semiconductor Devices by Using Laser Beam Probe

The optical noninvasive diagnostic of characteristic of silicon semiconductor de-vices by using a InGaAsP/InP semiconductor laser as an optical probe is reported.The princi-ple of experimental method is based on the dependence of the optical refractive index on the carrier charge density in the active region of devices and detection of variation of refractive index by two laser beam interferometric techniques.     

Charge carrier recombination and generation analysis in materials and devices by electron and optical beam microscopy

Electron beam induced current (EBIC) and optical beam induced current (OBIC) methods of scanning microscopy are here described in view of their applications in the analysis of recombination and generation of carriers in devices and materials. These analyses allow to evidence peculiarities in the charge carriers transport and/or failure in devices charge collection, measuring electrical parameters in the micrometer range, such as potential distribution within the sample, diffusion length and surface recombination velocity. This review will illustrate some case studies relevant to devices and material investigations in the two geometrical configurations: normal and planar. Literature results are reviewed in order to show capabilities and effectiveness of these methods in the investigation of the defect electrical activity and resulting localized minority carrier recombination and generation in devices under operating conditions, as well as in native semiconductor materials such as silicon, gallium arsenide and gallium nitride.     

Infrared Focal Planes in Intrinsic Semiconductors

In this paper, we review the state-of-the-art of intrinsic semiconductor detector arrays and project future areas of development. Infrared focal planes in intrinsic semiconductors offer advantages over extrinsic semiconductor structures in both operating temperature and quantum efficiency. Although the device function of spectral filtering and detection of the incident photon flux is now well understood in intrinsic semiconductors, the function of signal processing has only recently been investigated. As a result, research is directed toward implementation of both hybrid devices, in which the signal processing is accomplished in a silicon multiplexer which is physically and electrically interfaced with an intrinsic semiconductor detector array, and monolithic charge transfer devices in which detection and signal processing are accomplished in the same semiconductor. In the monolithic approach, charge transfer devices have been demonstrated in InSb, and it is likely that similar devices will be realized in InSb related alloys and HgCdTe in the near future. Demonstration of a non-MIS charge transfer design would open up the monolithic approach to the IV-VI alloys. Hybrid focal planes incorporating /spl lsim/1000 element photodiode arrays have been realized in the III-V and the IV-VI alloys; the detector-multiplexer interface circuit will remain one of the key technical issues in the achievement of a high-performance hybrid focal plane.     

Infrared focal planes in intrinsic semiconductors

In this paper, we review the state-of-the-art of intrinsic semiconductor detector arrays and project future areas of development. Infrared focal planes in intrinsic semiconductors offer advantages over extrinsic semiconductor structures in both operating temperature and quantum efficiency. Although the device function of spectral filtering and detection of the incident photon flux is now well understood in intrinsic semiconductors, the function of signal processing has only recently been investigated. As a result, research is directed toward implementation of both hybrid devices, in which the signal processing is accomplished in a silicon multiplexer which is physically and electrically interfaced with an intrinsic semiconductor detector array, and monolithic charge transfer devices in which detection and signal processing are accomplished in the same semiconductor. In the monolithic approach, charge transfer devices have been demonstrated in InSb, and it is likely that similar devices will be realized in InSb related alloys and HgCdTe in the near future. Demonstration of a non-MIS charge transfer design would open up the monolithic approach to the IV-VI alloys. Hybrid focal planes incorporating ≳ 1000 element photodiode arrays have been realized in the III-V and the IV-VI alloys; the detector-multiplexer interface circuit will remain one of the key technical issues in the achievement of a high-performance hybrid focal plane.     

Direct determination of doping concentration and built-in voltage from extraction current transients

We have extended the analytical framework of the charge extraction by linearly increasing voltage (CELIV) theory to the case with doping, taking the effect of built-in voltage, diffusion and band-bending into account. Not taking the built-in voltage into account in dark CELIV will lead to an underestimation of the charge carrier density, while the mobility is overestimated. Furthermore, based on the analysis we propose to use CELIV in the doping-induced capacitive regime for direct determination of doping concentration and built-in voltage from extraction current transients in the time-domain of doped thin-film semiconductor devices. The analytical framework is confirmed numerically with a one-dimensional drift–diffusion model and experimentally on aged P3HT:PCBM bulk heterojunction solar cell devices. An excellent agreement between the experimental extraction current transients and the analytical prediction is found. The presented analytical treatment is not limited to sandwich-type thin-film devices, but is more general and the technique can also be extended to pn-junctions.     

Charge current polarization and magnetoresistance in ferromagnetic/organic semiconductor/ferromagnetic devices

Spin-polarized injection and transport in ferromagnetic/organic semiconductor/ferromagnetic devices are studied theoretically. Based on the spin diffusion theory and Ohm’s law, we obtain the charge current polarization and the magnetoresistance, which takes into account the special carriers in organic semiconductors. From the calculation, it is found that the charge current polarization decreases exponentially from the ferromagnetic layer into the organic layer and polarons are effective spin carriers in organic semiconductors for polarized charge current. To get an apparent magnetoresistance in an organic device, it is better to adopt a spin-dependent interface, and the thickness of the organic interlayer is much smaller than the spin diffusion length. Spin polarons are effective carriers for gaining remarkable magnetoresistance in ferromagnetic/organic semiconductor/ferromagnetic devices.     

电荷耦合器件信号电荷转移的数值模拟

建立了线阵埋沟CCD的器件物理模型和数值模拟方法;运用半导体器件模拟软件MEDICI,数值模拟了CCD信号电荷在三相时序脉冲驱动下动态转移过程;模拟计算了CCD电荷转移效率随信号电荷包大小的变化以及暗电子数随埋沟掺杂浓度大小的变化情况。数值模拟结果与理论分析、实验测试结果吻合较好。     

Simulation for signal charge transfer of charge coupled devices

Physical device models and numerical processing methods are presented to simulate a linear buried channel charge coupled devices (CCDs). The dynamic transfer process of CCD is carried out by a three-phase clock pulse driver. By using the semiconductor device simulation software MEDICI, dynamic transfer pictures of signal charges cells, electron concentration and electrostatic potential are presented. The key parameters of CCD such as charge transfer efficiency (CTE) and dark electrons are numerically simulated. The simulation results agree with the theoretic and experimental results.     

Growth of Large Crystalline Grains of Vanadyl‐Phthalocyanine without Epitaxy on Graphene

The performance of organic semiconductor thin films in electronic devices is related to their crystal structure and morphology, with charge transport mobility dependent on the degree of crystallinity and on the crystallographic orientation. Here organic molecular beam deposition of vanadyl phthalocyanine is studied on graphene and it is shown that crystalline grains up to several micrometers across can be formed at substrate temperatures of 155 °C, compared to room temperature grain sizes of ≈30 nm. Transmission electron microscopy confirms the presence of long range order at elevated substrate temperatures and reveals that the molecules are stacked in an edge‐on orientation, but are not epitaxially aligned to the graphene. The crystalline grain sizes are significantly larger on graphene than on disordered substrates such as graphene oxide and silicon oxide. The effect on charge transport is probed by conducting atomic force microscopy, with the high temperature films on graphene showing increased mobility and uniformity and decreased trap density. These results illustrate an important advantage for the integration of graphene electrodes with organic semiconductor devices: the homogeneous surface of graphene results in high diffusion and low nucleation rates for thin film growth, encouraging the formation of highly crystalline films even with nonepitaxial growth.     

扫描静电力显微镜及其电荷捕获/释放技术

介绍扫描静电力显微测量及其用实现电荷捕获释放的技术现状，发展动向，以及关键技术的一些最新成果，前者已被广泛应用于测量半导体表面电荷密度分布，表面电势以及铁电材料铁电体结构的研究中，后者可望用于研制速度和存贮容量都比现在提高成千上万倍的量子器件。最后，本文探讨了基于微晶振的静电力显微测量的关键技术及其解决方案。     

半导体器件内离子有效LET值测量方法研究

提出了一种基于电荷收集测试技术的离子有效LET值测量方法.首先对半导体器件内收集电荷量与入射离子有效LET值之间的关系进行了分析,根据二者之间的关系提出通过测量电荷收集量从而测量离子有效LET值的方法;然后建立了半导体器件电荷收集测试系统,利用PN结和SRAM对测量方法进行了验证;最后成功利用该方法解释了以往单粒子效应实验中出现的数据异常.     

Lattice vibration, optical, and mechanical properties of aluminum phosphide (AlP) compound under the influence of temperature

<正>We have studied the lattice vibrations, optical and mechanical characteristics of the zinc-blende aluminum phosphide(Al P) compound. Investigations have been done into the effect of temperature on refractive index, optical dielectric constant, static dielectric constant, longitudinal and transversal sound velocities, reflectivity, susceptibility, phonon frequencies, micro-hardness, ionicity, and transverse effective charge. Al P is a wide-indirect band gap semiconductor and has a wide r...     

Novel SONOS – type nonvolatile memory device with stacked tunneling and charge trapping layers

Operation properties of polysilicon–oxide–nitride–oxide–silicon (SONOS)-type nonvolatile semiconductor memory (NVM) devices with stacked tunneling and charge trapping layers were investigated in this work. Clear enhancement on operation speed and satisfactory retention of NVM device were achieved by adopting stacked tunneling oxide. Enhancement on programming speed but degradation on erasing operation was observed for device with stacked charge trapping layer. Finally, operating characteristics of devices with stacked tunneling oxide, stacked charge trapping layer, and combining both stacked tunneling oxide and charge trapping layer were compared and discussed.     

Reliability of new semiconductor devices for long-distance opticalsubmarine-cable systems

Results from reliability tests conducted on three types of semiconductor devices used in optical repeaters are reported. The devices tested are: two types of 1.3-μm-band InGaAsP/InP laser diodes: a Ge avalanche photodiode; and monolithic integrated circuits. The devices have proved to be suitable for use in a long-distance optical submarine-cable system, such as the third transpacific cable system     

Microstrip Transmission On Semiconductor Dielectrics

As a result of both a larger number of microwave functions performed by semiconductor devices and a larger number of functions required in modern systems, it has become highly desirable from both the system and the device standpoint to fabricate multiple microwave semiconductor devices on a common substrate. The use of multiple devices in a single package has system and reliability advantages, but there is also offered the possibility of improved performance of the microwave components. This results from the elimination of packaging of each individual element and the ability to place the package interface in a more advantageous position in the circuit. To effect such an improvement, an efficient means of microwave interconnection must be available. The interconnections must have not only low dissipative losses through the microwave region, but be capable of providing the impedances necessary for transformations by the various microwave functions and for circuit resonating elements. The range of impedance commonly required is of the order of 20 /spl Omega/ to 80/spl Omega/. To be compatible with semiconductor materials and processing, the choice of dielectric material was limited to film dielectrics, possibly SiO/sub 2/, or the use of the semiconductor material itself as a dielectric. For both semi-insulating gallium arsenide and silicon of resistivity greater than 1000 /spl Omega/-cm, the loss is sufficiently low to perform efficient interconnection of devices on a common substrate and is considered even suitable for other components such as directional couplers and hybrids where extremely high Q is not required.