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1.
Lattice-Matched InP-Based HEMTs with fT of 120GHz   总被引:3,自引:3,他引:0       下载免费PDF全文
Lattice-matched InP-based InAlAs/InGaAs HEMTs with 120GHz cutoff frequency are reported.These devices demonstrate excellent DC characteristics:the extrinsic transconductance of 600mS/mm,the threshold voltage of -1.2V,and the maximum current density of 500mA/mm.  相似文献
2.
截止频率为120GHz的晶格匹配InP基HEMT   总被引:1,自引:0,他引:1  
报道了具有良好直流特性的晶格匹配InP基HEMT,器的跨导为600mS/mm,阈值电压为-1-2V,最大电流密度为500mA/mm,截止频率为120GHz.  相似文献
3.
我们成功研制了栅长88 nm, 栅宽2 50 μm, 源漏间距为2.4 μm 的InP基In0.53Ga0.47As/In0.52Al0.48As高电子迁移率器件(HEMT)。栅是使用PMMA/Al/UVⅢ,通过优化电子束曝光时间及其显影时间的方式制作的。这些器件有比较好的直流及其射频特性:峰值跨导、最大源漏饱和电流密度、开启电压、ft和fmax 分别为765 mS/mm, 591 mA/mm, -0.5 V, 150 GHz 和201 GHz。这些器件将非常适合于毫米波段集成电路。  相似文献
4.
An analytical parasitic resistance dependent model for the current voltage characteristics for InAlAs/InGaAs/InP HEMT is proposed. The model uses a new polynomial dependence of sheet carrier concentration on gate voltage to calculate IdVd characteristics and has been extended to obtain transconductance, output conductance and cut-off frequency of the device. A maximum cut-off frequency of 83 and 175 GHz was obtained for channel length of 0.25 and 0.1 μm, respectively. Close agreement with published results confirms the validity of our approach.  相似文献
5.
In the proposed work the model has been formulated for discretized doped HEMT, where the conventional uniformly doped, pulsed doped and delta doped structure are the special cases. An expression for sheet carrier density has been formulated considering the effect of doping-thickness product and has been extended to calculate drain current, transconductance, capacitance and cut-off frequency of the device. The model also takes into account the non-linear relationship between sheet carrier density and quasi Fermi energy level to validate it from subthreshold region to high conduction region. The results so obtained have been compared with pulsed doped structure to validate the model. The analysis concentrates on the distance of doping from the heterojunction and gate electrode. Different design criteria have been given to dope the carriers (amount and distance) in different regions to optimize the performance for higher sheet carrier density/parallel conduction voltage/effective parallel conduction voltage (Vc−Voff) to increase the transconductance, cut-off frequency and reliability of the device.  相似文献
6.
Effectively atomically flat interfaces over a macroscopic area (“(411)A super-flat interfaces”) were successfully achieved in In0.53Ga0.47As/In0.52Al0.48As quantum wells (QWs) grown on (411)A InP substrates by molecular beam epitaxy (MBE) at a substrate temperature of 570°C and V/III=6. Surface morphology of the In0.53Ga0.47As/In0.52Al0.48As QWs was smooth and featureless, while a rough surface of those simultaneously grown on a (100) InP substrate was observed. Photoluminescence (PL) linewidths at 4.2 K from the (411)A QWs with well width of 0.6–12 nm were 20–30 % narrower than those grown on a (100) InP substrate and also they are almost as narrow as each of split PL peaks for those of growth-interrupted QWs on a (100) InP substrate. In the case of the (411)A QWs, only one PL peak with very narrow linewidth was observed from each QW over a large distance (7 mm) on a wafer.  相似文献
7.
We have achieved a self-controlled asymmetrical etching in metalorganic chemical vapor deposition-grown InAlAs/InGaAs heterostructures, which can be suitable for fabricating modulation-doped field-effect transistors (MODFETs) with gate-groove profiles for improved performance. The technology is based on electrochemical etching phenomena, which can be effectively controlled by using different surface metals for ohmic electrodes. When surface metals of Pt and Ni are deposited on the source and the drain, respectively, the higher electrode potential of Pt results in slower etching on the source side than on the drain side. Thus, asymmetry of gate grooves can be formed by wet-chemical etching with citric-acid-based etchant. This represents a new possibility to conduct “recess engineering” for InAlAs/InGaAs MODFETs.  相似文献
8.
Low temperature photoluminescence (PL) has been used to characterize InAlAs/InGaAs/InP heterojunction field-effect transistor (HFET) structure material. A phenomenological lineshape model has been applied to the PL spectrum to derive energy levels and the position of the Fermi-energy and hence the channel carrier concentration. The data is compared with results from low-temperature Hall and Shubnikov-de Hans (SdH) measurements, and fit with a charge-control model of the conduction band. Values for the sheet density are derived from PL for channel-doped structures where SdH measurements are difficult. Changes in the quantum well symmetry through variations in the dopant distribution are shown to be reflected in the PL lineshape.  相似文献
9.
We have investigated, as a function of indium content x, the galvanomagnetic and Shubnikov de Haas (SdH) properties of two-dimensional electron gases (2DEG) formed at lattice matched, strain relaxed InAlAs/InGaAs heterojunctions. These were grown by molecular beam epitaxy on GaAs misoriented substrates with a two degree offcut toward the nearest (110) plane. Variable temperature resistivity and Hall measurements indicate an increase in the electron sheet density ns from 0.78×1012cm−2 for x=0.15 to 1.80×1012 cm−2 for x=0.40 at 300K, and from 0.75×1012cm−2 to 1.67×1012cm−2 at T=1.6K. The room temperature electron mobility, measured along the in plane [110], direction is independent of indium content and equals approximately 9500 cm2/Vs. For T<50K, the mobility is independent of temperature decreasing with increasing x from 82000 cm2/Vs for x=0.15 to 33000 cm2/Vs for x=0.40. The ratios (τtq) at 1.6K between the electron relaxation time τt and the single particle relaxation time τq, for the strain relaxed specimens, as well as for pseudomorphically strained Al0.35Ga0.65As/In0.15Ga0.85As structures grown on GaAs substrates, and In0.52Al0.48As/In0.53Ga0.47As heterostructures grown lattice matched on InP substrates. Such a study indicates the presence of inhomogeneities in the 2DEGs of the strain relaxed specimens which appear to be related to the process of strain relaxation. Such inhomogeneities, however, have little effect on the electron relaxation time τt which, at low temperatures, is limited principally by alloy scattering.  相似文献
10.
报道了用 MBE技术生长的 Ga As基 In Al As/In Ga As改变结构高电子迁移率晶体管 (MHEMT)的制作过程和器件的直流性能。对于栅长为 0 .8μm的器件 ,最大非本征跨导和饱和电流密度分别为 3 5 0 m S/mm和1 90 m A/mm。源漏击穿电压和栅反向击穿电压分别为 4V和 7.5 V。这些直流特性超过了相同的材料和工艺条件下 Ga As基 PHEMT的水平 ,与 In P基 In Al As/In Ga As HEMT的性能相当  相似文献
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