Investigation of a new InGaP-InGaAs pseudomorphic double doped-channel heterostructure field-effect transistor (PDDCHFET)

An interesting new InGaP-InGaAs pseudomorphic double doped-channel heterostructure field-effect transistor (PDDCHFET) is fabricated and demonstrated. Due to the employed InGaAs double doped channel (DDC) structure and Schottky behaviors of InGaP "insulator," good dc properties including higher turn-on voltage, lower leakage current, better linearity, and good RF performances are obtained. In addition, the experimental results are fitted well with theoretical simulation data based on a two-dimensional (2-D) simulator. Moreover, the studied device exhibits relatively negligible temperature-dependent characteristics over a wide operating temperature region (300相似文献   

Degradation of DC characteristics of InGaAs/InP singleheterojunction bipolar transistors under electron irradiation

The effects of high-energy (~1 MeV) electron irradiation on the dc characteristics of InGaAs/InP single heterojunction bipolar transistors (SHBT's) are investigated. The device characteristics do not show any significant change for electron doses <10¹⁵/cm². For higher doses, devices show a decrease in collector current, a degradation of common-emitter current gain, an increase in collector saturation voltage and an increase in the collector output conductance. A simple SPICE-like device model is developed to describe the dc characteristics of SHBT's. The model parameters extracted from the measured dc characteristics of the devices before and after irradiation are used to get an insight into the physical mechanisms responsible for the degradation of the devices     

4×288 TDI CCD信号读出电路

采用硅工艺设计、制作了4×288 TDI CCD红外焦平面HgCdTe阵列专用信号读出电路。文章详细介绍了4×288 TDI CCD信号读出电路的设计及制作,并给出了测试结果。     

一种高性能InP基谐振隧穿二极管的研制

设计并用分子束外延技术生长了InP基InGaAs/AlAs体系RTD材料,采用传统湿法腐蚀、光学接触式光刻、金属剥离、台面隔离和空气桥互连工艺,研制出了具有优良负阻特性和较高阻性截止频率的InP基RTD单管，器件正向PVCR为17.5,反向PVCR为28,峰值电流密度为56kA/cm^2,采用RNC电路模型进行数据拟合后得到阻性截止频率为82.8GHz，实验为今后更高性能RTD单管的研制,以及RTD与其他高速高频三端器件单片集成电路的设计与研制奠定了基础。     

“GAMBIT: GAte Modulated BIpolar Transistor”

A planar, interdigitated, integrated device structure is described whose characteristics show a voltage controlled negative resistance between two of its terminals. This negative resistance can be controlled by the applied bias to a third terminal. Devices have been fabricated with this structure to achieve negative resistance values ranging from a few hundred thousand ohms down to less than a hundred ohms. The physical mechanisms that give rise to this negative resistance are described and a dc analysis of its behavior is presented. The analysis shows excellent agreement with the observed device characteristics.     

Modulation-doped AlGaAs/GaAs heterostructure charge coupled devices

The advantages of the modulation-doped heterostructure over conventional materials structures for high speed CCD applications are outlined. In addition, the first demonstration of charge transfer in a modulation-doped AlGaAs/GaAs heterojunction is reported. A ten cell, three phase Schottky barrier gate CCD was fabricated using this structure and operated as a shift register. The details of the device fabrication and characterization are presented.     

Micromachined Display Device Using Sheet Waveguide and Multicantilevers Driven by Electrostatic Force

A new structure for display devices is proposed and fabricated by the microelectromechanical systems process. The device is based on physical contact and evanescent coupling between a sheet waveguide and electrostatically driven multicantilevers. When incident light is propagated into the waveguide and the cantilevers contact the waveguide by applying a dc voltage, the switched light is emitted from the side edges of the contacted multicantilevers, resulting in a display device. The device contributes to the expansion of the switching area, the removal of unnecessary scattered light, and high contrast due to the simple fabrication and structure with corner spacers for the optical separation between the cantilevers and the waveguide. Based on the experimental results with the device, a contrast of 0.9 is obtained at 170 V, and a stable drive is realized up to 1 kHz. Therefore, the device can be expected to be used for display devices by the fabrication of an array structure.     

Device performance improvement of InGaP/InGaAs doped-channel FETs

Partial drain/source ohmic recess InGaP/InGaAs/GaAs doped-channel field-effect transistors (OR-DCFETs) are proposed and fabricated in this study. The proposed ohmic recess process reduces the parasitic ohmic alloyed resistance caused by the undoped Schottky layer and therefore improves the device performance in terms of dc and source resistance, as well as RF characteristics. We compare the proposed devices with the DCFETs using the conventional process by means of experiments, where the Yang-Long method is used to analyze the effect of parasitic source resistances.     

0.25μm GaAs基MHEMT器件

采用普通接触曝光研制成栅长为0 .2 5 μm的Ga As基In Al As/ In Ga As变组分高电子迁移率晶体管(MHEMT) ,测得其跨导为5 2 2 m S/ m m,沟道电流密度达4 90 m A/ mm,截止频率为75 GHz,比同样工艺条件下Ga As基In Ga P/ In Ga As PHEMT的性能有很大的提高.对该器件工艺及结果进行了分析,提取了器件的交流小信号等效电路模型参数,并提出了进一步得到高稳定性、高性能器件的方法.     

High-density 3-D packaging technology based on the sidewall interconnection method and its application for CCD micro-camera visual inspection system

High-density three-dimensional (3-D) packaging technology for a charge coupled device (CCD) micro-camera visual inspection system module has been developed by applying high-density interconnection stacked unit modules. The stacked unit modules have fine-pitch flip-chip interconnections within Cu-column-based solder bumps and high-aspect-ratio Cu sidewall footprints for vertical interconnections. Cu-column-based solder bump design and underfill encapsulation resin characteristics were optimized to reduce the strain in the bump so as to achieve fine-pitch flip-chip interconnection with high-reliability. High-aspect-ratio Cu sidewall footprints were realized by the Cu-filled stacked vias at the edge of the substrate. High-precision distribution of sidewall footprints was achieved by laminating the multiple stacked unit substrates simultaneously. The fabricated high-density 3-D packaging module has operated satisfactorily as the CCD imaging data transmission circuit. The technology was confirmed to be effective for incorporating many large scale integrated (LSI) devices of different sizes at far higher packaging density than it is possible to attain using conventional technology. This paper describes the high-density 3-D packaging technology which enables all of the CCD imaging data transmission circuit devices to be packaged into the restricted space of the CCD micro-camera visual inspection system interior.     

Characterization of ultra-high-speed pseudomorphic AlGaAs/InGaAs(on GaAs) MODFETs

The authors report a detailed characterization of ultrahigh-speed pseudomorphic AlGaAs/InGaAs (on GaAs) modulation-doped field-effect transistors (MODFETs) with emphasis on the device switching characteristics. The nominal 0.1-μm gate-length device exhibit a current gain cutoff frequency (f_t) as high as 152 GHz. This value of f_t corresponds to a total delay of approximately 1.0 ps and is attributed to the optimization of layer structure, device layout, and fabrication process. It is shown that the electron transit time in these very short gate-length devices still accounts for approximately 60% of the total delay, and, as a result, significant improvements in switching speed are possible with further reductions of gate length. The results reported clearly demonstrate the potential of the pseudomorphic AlGaAs/InGaAs MODFET as an ultrahigh-speed device. Its excellent switching characteristics are attributed to the high saturation velocity (~2×10⁷ cm/s), 2DEG sheet density (2.5×10¹² cm^-2), and current drive capability (>200 mA/mm at the peak transconductance)     

Thermal-oxide gate GaAs MOSFET's

The first thermal-oxide gate GaAs MOSFET of the deep-depletion mode is reported. The gate oxide, which has been grown by the new GaAs oxidation technique in the As2O3vapor, is so chemically stable that it can be subjected to the fabrication process. Measurement of some dc characteristics of the device fabricated has shown a strikingly suppressed hysteresis.     

All-refractory GaAs FET using amorphous TiWSixsource/drain metallization and graded-InxGa1-xAslayers

We report on the fabrication of an all-refractory GaAs field-effect transistor having non-alloyed source and drain ohmic contacts and a TiW/Au refractory gate metallization. The ohmic contacts consist of amorphous TiWSi_x metallization and intervening graded InGaAs layers grown by low pressure organometallic vapor phase epitaxy (LPOMVPE). The amorphous TiWSi_x, is formed using alternating layers of TiW(10 Å) and Si(1.5 Å) deposited by an RF magnetron sputtering technique. The resulting all-refractory FET devices exhibited excellent dc transistor characteristics with measured transconductance of 140 mS/mm. The dc performance of these devices was comparable to conventional devices with AuGe/Ni/Au contacts fabricated using similar material structures     

Design, Fabrication, and Operation of Two-Dimensional Conveyance System With Ciliary Actuator Arrays

In this paper, we present the design, fabrication, and operation of a two-dimensional (2-D) microconveyance system. Conceptually, this system was designed as a mechanical part of an autonomous decentralized system composed of integrated micro actuator–sensor–controller cells. The presented system is a 2-D ciliary motion system (2-D CMS) composed of arrayed cantilever actuators. The actuators are made of two types of polyimide with different thermal expansion coefficients. They are thermally driven by flowing current in laminated heaters between the polyimide layers. We investigated the 2-D conveyance characteristics of the 2-D CMS consisting of $20 times 20$ cells. Each cell has a pitch of 1420 $mu$m consisting of four actuators of 500 $mu$m in length. The conveyance was performed in a voltage range of 19–32 V, which corresponds to approximately 48–136 mW/cell, in a frequency range of 1–100 Hz, which corresponds to approximately 2–18 $mu$m of minimum step size. We operated it in a feedback control scheme. In feedback operation mode, the 2-D CMS was controlled with a charge-coupled device (CCD) camera regulated by a PC and a programmable logic device (PLD). We succeeded to convey an object to a predetermined target point on the surface of the CMS.      

InGaAs探测器片上集成滤光膜的微结构与性能

为了适应未来红外焦平面探测器系统小型化、集成化和高精度的发展要求,采用了热蒸发方法分别在InP衬底和InGaAs探测器上实现了中心波长为1.38μm滤光膜的片上集成。利用偏光显微镜、原子力显微镜(AFM)和扫描电子显微镜(SEM)以及红外傅里叶光谱(FTIR)等实验手段研究了滤光膜的表面界面形貌和光学性能,结果显示,滤光膜为法布里-珀罗三谐振腔结构,与膜系设计一致;滤光膜中心波长为1.38μm,透射率在60%左右。对集成滤光膜InGaAs器件的电学和光学性能测试分析表明,滤光膜制备工艺对器件的电流电压特性和噪声基本没有影响;而集成滤光膜器件的响应要优于滤光膜分离器件的性能。     

A Programmable Lens-Array Antenna With Monolithically Integrated MEMS Switches

This paper describes a reconfigurable millimeter-wave lens-array antenna based on monolithically integrated microelectromechanical systems (MEMS) switches. This device is constructed as a planar array of 2-bit programmable MEMS antenna–filter–antenna (AFA) unit cells that are used to provide a 1-D programmable “aperture transfer function” between the input and output wavefronts. The fully integrated device consists of 484 (22 $times$ 22) AFA elements and 2420 switches. Switches, bias lines, antennas, and the rest of the RF structure are fabricated on two quartz wafers ($varepsilon_{ r}=3.8$, $tandelta=0.002$) that are subsequently stacked using adhesive bonding to form the tri-layer metal structure of the AFA array. The bonded structure also forms a package for the MEMS switches. This paper investigates the design and fabrication issues and presents the measured data related to yield and frequency response of this lens-array. It also characterizes the performance of this device as a steerable antenna. Measured results show that this lens-array can be used to steer the beam of a low gain horn antenna to $pm {hbox{40}}^{circ}$ in either the $E$- or the $H$-plane. For the fabricated prototype, the yield is estimated to be 50% for the best region of the array, resulting in a relatively high insertion loss and sidelobe level.      

A high-current metal—Semiconductor rectifier

Schottky-barrier diodes have been in use for some time, but, in the main, only for small-signal applications. Now a large area (17K mils²) Schottky-barrier diode has been successfully fabricated for use as a high-current rectifier. The device has a rated Io of 50 amperes. Measured values of forward voltage drop at 50 amperes (dc) are typically less than 500 mV. The inherent speed characteristics of this majority carrier device were indicated in the measurement of rectification efficiency versus frequency. The efficiency of the device remained unchanged through 500 kHz. A brief theoretical review of metal-semiconductor junctions is presented and applied to the empirical characteristics of the rectifier. Chip geometry, fabrication techniques, and complete device characteristics are discussed. Specific device applications are covered with emphasis on performance and limitations.     

AlGaAs／InGaAs功率PHEMT用异质材料的计算机优化与器件实验结果

借助一新的工艺模拟与异质器件模型用ＣＡＤ软件──ＰＯＳＥＳ（Ｐｏｉｓｓｏｎ－ＳｃｈｒｏｅｄｉｎｇｅｒＥｑｕａｔｉｏｎＳｏｌｖｅｒ），对以ＡｌＧａＡｓ／ＩｎＧａＡｓ异质结为基础的多种功率ＰＨＥＭＴ异质层结构系统（传统、单层与双层平面掺杂）进行了模拟与比较，确定出优化的双平面掺杂ＡｌＧａＡｓ／ＩｎＧａＡｓ功率ＰＨＥＭＴ异质结构参数，并结合器件几何结构参数的设定进行器件直流与微波特性的计算，用于指导材料生长与器件制造。采用常规的ＨＥＭＴ工艺进行ＡｌＧａＡｓ／ＩｎＧａＡｓ功率ＰＨＥＭＴ的实验研制。对栅长０．８μｍ、总栅宽１．６ｍｍ单胞器件的初步测试结果为：ＩＤｓｓ２５０～４５０ｍＡ／ｍｍ；ｇｍ０２５０～３２０ｍＳ／ｍｍ；Ｖｐ－２．０－２．５Ｖ；ＢＶＤＳ５～１２Ｖ。７ＧＨｚ下可获得最大１．６２Ｗ（功率密度１．０Ｗ／ｍｍ）的功率输出；最大功率附加效率（ＰＡＥ）达４７％。     

量子共振隧穿二极管的频率特性与分析

用HP8510C网络分析仪测量了AlAs/InGaAs/AlAs共振隧穿二极管的S参数,通过实测曲线拟合提取器件等效电路参数,计算出所研制器件的阻性截止频率为54GHz,并分析了影响器件工作频率的因素.     

Broadband InGaAs PIN Traveling-Wave Switch Using a BCB-Based Thin-Film Microstrip Line Structure

This letter describes the design and fabrication of a broadband InGaAs PIN traveling wave switch. A new thin-film microstrip line structure integrated with InGaAs PIN diodes has been used to enhance the switch performance at higher frequencies. The developed InGaAs PIN switch has an insertion loss of less than 3.2 dB and an isolation of greater than 40 dB in a broadband frequency range from 25 to 95 GHz. The BCB-based multi-layer technology effectively reduces the chip size of the fabricated SPDT MMIC switch to 1.05 times 0.58 mm². To our knowledge, this is the first InGaAs PIN traveling-wave switch demonstrated up to 95 GHz.