GaAs MMIC应用展望

ＧａＡｓ　ＭＭＩＣ应用展望本刊主编林金庭中图分类号：ＴＮ４５４ＰｅｒｓｐｅｃｔｉｖｅｏｆＧａＡｓＭＭＩＣｓＡｐｐｌｉｃａｔｉｏｎ￥ＬｉｎＪｉｎｔｉｎｇ１９９０年以前，砷化镓（ＧａＡｓ）技术的８０％是用于军事，随着冷战结束，高性能的ＧａＡｓＩＣ向何处去...     

GaAs单片电路封装

简述了微波在封装中的传输特性，以及不同封装型式和材料的ＧａＡｓＭＭＩＣ封装，介绍了多层共烧陶瓷在ＭＭＩＣ封装中的应用。最后，综述了国外ＧａＡｓＭＭＩＣ的最新封装与互连技术。     

X和Ku波段GaAs MMIC低噪声放大器的测量及其研究

讨论了微波电性能测量在ＧａＡｓＭＭＩＣ研制和开发中的重要作用，研究了Ｘ和Ｋｕ波段ＧａＡｓＭＭＩＣＬＮＡ微波电性能测量及其测量系统设计所要注意的有关问题。给出了相关增益、噪声系数、输入和输出驻波比的测试结果，并介绍了这两个频段ＧａＡｓＭＭＩＣＬＮＡ的应用情况。     

GaAs器件及MMIC的可靠性研究进展

介绍了国外ＧａＡｓ微波器件及ＭＭＩＣ的可靠性研究进展情况，给出ＧａＡｓＭＥＳＦＥＴ、ＨＥＭＴ和ＭＭＩＣ的主要失效模式和失效机理以及在典型沟道温度下的平均寿命代表值。     

GaAs IC CAD及其在通信电路中的应用技术

介绍了自主开发的多个完整实用的ＧａＡｓ ＩＣ ＣＡＤ软件,包括微波无源元件建模、微波有源器件测试建模、微波毫米波ＩＣ ＣＡＤ、光电集成电路ＣＡＤ、ＧａＡｓ ＶＨＳＩＣ ＣＡＤ、微波高速ＭＣＭ ＣＡＤ等,并简要介绍了针对ＧａＡｓ工艺线的建库工作。以上软件和库已用于多个通信电路的设计。     

GaAs MMIC在移动通信中的应用

便携式无线通信系统是ＧａＡｓＭＭＩＣ潜在的民用大户。在简要陈述该新兴市场现状及前景的基础上，着重讨论ＧａＡｓＭＭＩＣ占据该市场并成为其核心技术的策略。     

高速GaAs驱动器

报道了和于驱动ＧａＡｓＭＭＩＣ射频开关的高速ＧａＡｓ驱动器的设计与制作。测试结果为：同相输出时，上升时间６ｎｓ，延迟时间４．８ｎｓ，下降时间６ｎｓ，延迟时间４ｎｓ；反相输出时，上升时间６．５ｎｓ，延迟时间３ｎｓ，下降时间１０ｎｓ，延迟时间６．７ｎｓ。与ＧａＡｓＭＭＩＣ射频开关进行了联试，结果不仅没有影响开关的射频特性，而且开关速度仍保持原来的水平。     

高速GaAs驱动器

报道了用于驱动ＧａＡｓＭＭＩＣ射频开关的高速ＧａＡｓ驱动器的设计与制作。测试结果为：同相输出时，上升时间６ｎｓ，延迟时间４．８ｎｓ，下降时间６ｎｓ，延迟时间４ｎｓ；反相输出时，上升时间６．５ｎｓ，延迟时间３ｎｓ，下降时间１０ｎｓ，延迟时间６．７ｎｓ。与ＧａＡｓＭＭＩＣ射频开关进行了联试，结果不仅没有影响开关的射频特性，而且开关速度仍保持原来的水平     

GaAs IC CAD方法

本文重点论述ＧａＡｓ ＩＣ ＣＡＤ方法，包括：精确的ＧａＡｓ ＭＥｓＦＥＴ、ＨＥＭＴ和ＨＢＴ等有源器件模型；大、小信号模型参数提取；噪声模型；成品优化；高频、高速微带传输线模型；电路模拟与优化；砷化镓门阵等。还评述了ＧａＡｓ ＩＣ ＣＡＤ集成软件包及进一步工作。     

GaAs MMIC射频开关设计与研制

介绍了ＧａＡｓ ＭＭＩＣ ＲＦ开关的设计方法,在这种方法中,把ＭＥＳＦＥＴ当作一个两端口网络处理,直接提取开与关两种状态下网络的Ｓ参数,应用Ｓ参数进行开关电路的ＣＡＤ。这种设计方法更准确,更简单,容易实现。文中还给出了ＧａＡｓ ＭＭＩＣ ＲＦ开关的研制结果。     

Application of low temperature GaAs to GaAs/Si

Low Temperature grown GaAs (LT-GaAs) was incorporated as a buffer layer for GaAs on Si (GaAs/Si) and striking advantages of this structure were confirmed. The LT-GaAs layer showed high resistivity of 1.7 × 10⁷ ω-cm even on a highly defective GaAs/Si. GaAs/Si with the LT-GaAs buffer layers had smoother surfaces and showed much higher photoluminescence intensities than those without LT-GaAs. Schottky diodes fabricated on GaAs/Si with LT-GaAs showed a drastically reduced leakage current and an improved ideality factor. These results indicate that the LT-GaAs buffer layer is promising for future integrated circuits which utilize GaAs/Si substrates.     

Effects of low temperatures and intensities on GaAs and GaAs/Gesolar cells

GaAs and GaAs/Ge solar cells grown by metalorganic chemical vapor deposition (MOCVD) were characterized at very low temperature (-185°C) and solar intensity (0.25 suns) to simulate the cell behavior in a severe interplanetary environment. A comparison is also made with GaAs cells grown with the liquid-phase-epitaxy (LPE) technique. The analysis carried out from -185 to +50°C shows, in particular, different behaviors for GaAs/Ge cells with active and passive Ge substrates; the GaAs/Ge passive cell behaves as a GaAs on GaAs cell, indicating that from the thermal and optical point of view, Ge acts only as a mechanical support. The GaAs cell with an active Ga substrate is affected by a notch in the I-V curves, which is more evident at low temperatures but reduces at low intensities. The GaAs/GaAs MOCVD cell shows the best performance at low temperature and intensity with a conversion efficiency of 27.2%     

Lateral ordering of GaAs nanowhiskers on GaAs(111)As and GaAs (110) surfaces during molecular-beam epitaxy

Possibilities of obtaining laterally ordered arrays of GaAs nanowhiskers on GaAs (110) and GaAs(111)As surfaces during the molecular beam epitaxy are considered. As in the case of the GaAs(111)As substrate, nanowhiskers are formed in the hexagonal phase on the GaAs(110) surface, which is also confirmed by the patterns of the reflection high-energy electron diffraction (obtained during the growth of nanowhiskers) and by the photoluminescence spectra.     

Characterization of interface stress at InGaPAs/GaAs by cr-related luminescence line in GaAs

The interface stress at InGaPAs/GaAs heterostructure has been investigated using the energy shift and splitting of the Cr-related zero-phonon photoluminescence line at 0.839 eV observed in GaAs. It has been found that the GaAs substrate suffers both compressive uniaxial stress and tensile hydrostatic pressure at the InGaPAs/GaAs heterointerface. These shifts and splittings of the 0.839 eV line have been systematically examined as a function of the lattice mismatch between InGaPAs and GaAs, and the thicknesses of the epitaxial-layer and substrate. The amount of the interface stress existing at InGaPAs/GaAs heterostructure has been estimated, based on uniaxial stress data for GaAs: Cr wafers.     

Sidegating effect of GaAs MESFETs in carbon doped GaAs substrate

The sidegating effect of GaAs MESFETs in carbon doped semi-insulating GaAs substrate was investigated. Measurement results suggest that both the hole injection at one part of the gate electrode, and the modulation of the width of the depletion layer near the interface between the channel and substrate, cause the sidegating effect of GaAs MESFETs. Also, with the increase of carbon concentration, the latter cause becomes dominant in the sidegating effect.<>     

Comparison of GaAs MESFET and GaAs p-i-n diodes as switch elements

The Kurokawa-Schlosser quality factor Q̂ is used to compare the GaAs MESFET switch with the GaAs p-i-n diode switch. The MESFET device parameters are governed by the power handling capability and the specified pinchoff voltage, and the switch Q̂ is calculated from an approximate expression. The GaAs p-i-n has been characterized using a simple diode model which is derived from detailed simulations. The comparison for typical devices shows that the GaAs pin has the higher Q̂ and therefore should have improved characteristics as a switch in terms of insertion loss and isolation.     

砷化镓集成电路CAD系统

介绍了一个在ＳＵＮ工作站上自主开发的砷化镓集成电路ＣＡＤ系统。该系统可完成微波、毫米波集成电路ＣＡＤ及砷化镓超高速数字集成电路ＣＡＤ。应用该系统已完成１５０余种砷化镓集成电路的优化设计，取得良好效果。     

砷化镓毫米波器件

叙述了GaAs MESFET、GaAs HEMT和GaAs耿氏器件等新一代GaAs毫米波器件的发展现状。     

GaAs MESFET's fabricated on monolithic GaAs/Si substrates

GaAs MESFET's have been fabricated for the first time on monolithic GaAs/Si substrates. The substrates were prepared by growing single-crystal GaAs layers on Si wafers that had been coated with a Ge layer deposited by e-beam evaporation. The MESFET's exhibit good transistor characteristics, with maximum transconductance of 105 mS/mm for a gate length of 2.1 µm.     

A dc and microwave comparison of GaAs MESFET's on GaAs and Si substrates

In order to assess GaAs on Si technology, we have made a performance comparison of GaAs MESFET's grown and fabricated on Si and GaAs substrates under identical conditions and report the first microwave results. The GaAs MESFET's on Si with 1.2-µm gate length (290-µm width) exhibited transconductances (gm) of 180 mS/mm with good saturation and pinchoff whereas their counterparts on GaAs substrates exhibited gmof 170 mS/mm. A current gain cut-off frequency of 13.5 GHz was obtained, which compares with 12.9 GHz observed in similar-geometry GaAs MESFET's on GaAs substrates. The other circuit parameters determined from S-parameter measurements up to 18 GHz showed that whether the substrate is Si or GaAs does not seem to make a difference. Additionally, the microwave performance of these devices was about the same as that obtained in devices with identical geometry fabricated at Tektronix on GaAs substrates. The side-gating effect has also been measured in both types of devices with less than 10-percent decrease in drain current when 5 V is applied to a pad situated 5 µm away from the source. The magnitude of the sidegating effect was identical to within experimental determination for all side-gate biases in the studied range of 0 to -5 V. The light sensitivity of this effect was also very small with a change in drain current of less that 1 percent between dark and light conditions for a side gate bias of -5 V and a spacing of 5 µm. Carrier saturation velocity depth profiles showed that for both MESFET's on GaAs and Si substrates, the velocity was constant at 1.5 × 10⁷cm/s to within 100-150 Å of the active layer-buffer layer interface.