Pb_(1-X)Ge_XTe(0.05≤X≤0.11)扩散结光伏红外探测器

用P型Pb_(1-x)Ge_xTe(0.05≤x≤0.11)通过锑杂质扩散形成n-p结已制成光伏红外探测器。在77和195K之间的温度下进行了测量,其长波响应截止是3.5～4.5微米。禁带宽度温度系数在低于铁电居里温度时为正而在高于该温度时即转变为负。     

新型Pathwork~(TM) RF放大器

一产品具有远端、本地监控和易于调整与维护的数字式控制的无线新技术的特点ＡＤＣ电讯公司的ＡＤＣ宽带通信部开发出全新的ＲＦ放大器和线路延伸器系列产品。ＰａｔｈｗｏｒｘｒＴＭ新型放大器提供经济有效的ＲＦ性能。１．专门为数据、电话和双向业务设计的ＲＦ放大器。其可靠性、可扩展性和易于维护融合于一个放大器系列中，为网络运营商提供可靠传送视频、话音和数据所需的性能。ＰａｔｈｗｏｒｘＴＭ系列还可以减少资金，降低运行及维护的费用。２．优良的ＲＦ性能可减少网络初始投资，并提供优良的网络可用性。Ｐａｔｈｗｏｒｘｒｕ系…     

Optical transitions of Al0.35Ga0.65As/GaAs asymmetric double quantum wells grown on GaAs(n11)A (n≤4) substrates

The optical transitions in Al_0.35Ga_0.65As/GaAs asymmetric double quantum wells (ADQWs) grown on GaAs(n11)A (n≤4) substrates were studied by photoluminescence at low temperatures. The redshift of two PL peaks for substrate orientation far from the (100) plane is attributed to the large anisotropy of the heavy-hole band in the different GaAs orientations. The energy difference of the two transitions also shows a similar shift. By comparing the PL measurements with a simple effective mass calculation, the effective mass of the heavy hole on GaAs(n11)A (n=1, 2, 3, 4) planes is found to be about 0.95, 0.73, 0.54 and 0.41m₀, respectively. The effect of As pressures on PL peak energies in ADQWs is also studied. The As pressure-dependence of PL peak energies is attibuted to a decrease of the Ga desporption rate with increasing As pressures on GaAs(n11)A substrates.     

MBE生长InGaAs/In_(0.32≤x≤0.52)Al_(1-x)As MM-HEMT材料

在GaAs衬底上利用分子束外延技术生长了不同In组分的MetamorphicHEMT(简称MM-HEMT)。通过对MM-HEMT材料中台阶式缓冲层材料种类、台阶宽度、初始组分以及生长温度等生长参数、生长条件和结构参数进行优化,得到了具有良好电学性能的MM-HEMT材料,其二维电子气迁移率和浓度指标与国外同期水平相当。     

900MHz砷化镓射频(RF)集成功率放大器

摩托罗拉半导体部宣布推出MRFIC0913砷化镓集成功率放大器。该款用于蜂窝电话的器件是经过专门设计以适合全球移动系统(GSM)手机。MRFIC0913放大器供电电压力4.8V,最小功率效益为48％,输出功率为2.8W。其输入/输出和干扰耦合是在片外完成的,允许器件在可用频率800MHz到1000MHz以上运行。     

铜过量对CuxAlO2(1≤x≤1.06)电学性能的影响

采用溶胶.凝胶法制备了铜铁矿结构CuxAlO2陶瓷体材.当1≤x＜1.04时,样品为纯铜铁矿相,当x≥1.04时,样品中出现了微弱的CuO相.样品Cu1.04AlO2的室温电导率比名义组分CuAlO2大了近一个数量级.研究表明,替位式缺陷CuAl(Cu2+离子取代Al3+离子)是导致电导增加的主要受主缺陷机制,Cu过量CuxAlO2的分子式可更准确地表示为Cu(Al1-yCuy)O2.     

铜过量对CuxAlO2(1≤x≤1.06)电学性能的影响

采用溶胶.凝胶法制备了铜铁矿结构CuxAlO2陶瓷体材.当1≤x＜1.04时,样品为纯铜铁矿相,当x≥1.04时,样品中出现了微弱的CuO相.样品Cu1.04AlO2的室温电导率比名义组分CuAlO2大了近一个数量级.研究表明,替位式缺陷CuAl(Cu2 离子取代Al3 离子)是导致电导增加的主要受主缺陷机制,Cu过量CuxAlO2的分子式可更准确地表示为Cu(Al1-yCuy)O2.     

Synthesis and Microwave Dielectric Properties of SrLa4−x Pr x Ti5O17 (0 ≤ x ≤ 4) Ceramics

Single-phase ceramics in the SrLa_4?x Pr _x La₄Ti₅O₁₇ (0 ≤ x ≤ 4) series were processed via a solid-state sintering route. X-ray diffraction analysis revealed single-phase ceramics for all the compositions. The molar volume (V _m) decreased while the theoretical density (ρ _th) increased with increase in the Pr content. Substitution of Pr³⁺ decreased the relative permittivity (ε _r) and temperature coefficient of resonant frequency (τ _f) due to its smaller ionic polarizability (α _d) and ionic radius than La³⁺. In the present study, ε _r ≈ 54.2, Q _u f ₀  ≈ 7935 GHz, and τ _f  ≈ ?20.3 ppm/°C were achieved for the composition with x = 2 (i.e., SrLa₂Pr₂Ti₅O₁₇).     

RF CMOS蓝牙收发器的设计(连载二)

该文介绍了一种设计方法,它是通过使用晶片厂模型、论证测试模板以及与测试仪器的链接,实现RFIC设计并很快获得原型芯片。描述了蓝牙收发器的设计,其中包括,在统一EDA环境下的仿真结果和硬件验证。     

Shallow–Deep InGaN Multiple-Quantum-Well System for Dual-Wavelength Emission Grown on Semipolar ($$ 11\bar{2}2 $$) Facet GaN

We report growth and characterization of a shallow–deep InGaN/GaN multiple-quantum-well (MQW) system for dual-wavelength emission grown on semipolar (11[`2]2 11\bar{2}2 ) facet GaN. Structural and optical properties of the InGaN multiple-quantum-well system were investigated by scanning electron microscopy (SEM), cross-sectional scanning transmission electron microscopy (XSTEM), photoluminescence (PL), photoluminescence excitation (PLE), and time-resolved photoluminescence (TRPL) measurements. Cross-sectional transmission electron microscopy (XTEM) revealed that the growth rate of the InGaN well layers on the (0001) flat top microfacet (~500 nm) was about six times as fast as on the (11[`2]2 11\bar{2}2 ) inclined facet, whereas the growth rate of GaN barrier layers on the (0001) flat top facet was roughly 4.5 times as large as that on the (11[`2]2 11\bar{2}2 ) facet. A room-temperature PL spectrum showed dual-wavelength light emission of the shallow–deep InGaN multiple-quantum-well system situated at 2.720 eV (455 nm) and 2.967 eV (418 nm). The Stokes shifts between the two PL peaks and the two “effective bandgaps” were ~260 meV in energy for the deep quantum wells and ~233 meV for the shallow quantum wells. The TRPL decay demonstrated the short radiative recombination lifetime on the order of several nanoseconds in the InGaN MQW system. Realization of the shallow–deep InGaN multiple-quantum-well system with emission wavelength controllability would be useful to achieve III-nitride-based multicolor light-emitting devices for displays.     

RF CMOS蓝牙收发器的设计(连载一)

该文介绍了一种设计方法,它是通过使用晶片厂模型、论证测试模板以及与测试仪器的链接,实现RFIC设计并很快获得原型芯片。描述了蓝牙收发器的设计,其中包括,在统一EDA环境下的仿真结果和硬件验证。     

RF CHOS蓝牙收发器的设计(连载二)

该文介绍了一种设计方法，它是通过使用晶片厂模型、论证测试模板以及与测试仪器的链接，实现RFIC设计并很快获得原型芯片。描述了蓝牙收发器的设计，其中包括，在统一EDA环境下的仿真结果和硬件验证。     

Semiconductor Yield Analysis and Multi-Chip Package(MCP) Dic Pairing Optimization using Machine Learning

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Comparative analysis of long-wavelength (1.3 µm) VCSELs on GaAs substrates

Two designs of vertical-cavity surface-emitting lasers (VCSELs) for the 1.3 μm spectral range on GaAs substrates with active regions based on InAs/InGaAs quantum dots and InGaAsN quantum wells are considered. The relationship between the active region properties and optical microcavity parameters required for lasing has been investigated. A comparative analysis is made of VCSELs with active regions based on InAs/InGaAs quantum dots or on InGaAsN quantum wells, which are fabricated by MBE and demonstrate room-temperature CW operation. Optimization of the vertical microcavity design provides single-pass internal optical losses lower than 0.05%. __________ Translated from Fizika i Tekhnika Poluprovodnikov, Vol. 35, No. 7, 2001, pp. 881–888. Original Russian Text Copyright ? 2001 by Maleev, Egorov, Zhukov, Kovsh, Vasil’ev, Ustinov, Ledentsov, Alferov.     

吉时利(Keithley)引进第三代晶圆射频(RF)测量功能

吉时利仪器公司(NYSE:KEI)一家为不断增长的测量需求提供解决方案的市场领导者,最近发布了用于半导体生产过程中参数测试的第三代晶圆射频(RF)测量功能。对于吉时利公司第三代射频(RF)参数测量系统方案(是一个选配件),其独特的新内容是能提供连续、自动、实时的测试质量监控,在提供优等质量结果的同时,也获得了最高测量产能、最低运行成本,以及易于使用的特点。此外,吉时利公司的射频(RF)参数测量选项是目前惟一一个在全球范围内获得验证的,适合于200m m和300m m晶圆制造工厂的半导体参数射频(RF)测试系统,适用于包括高性能逻辑电路生…