共查询到20条相似文献,搜索用时 15 毫秒
1.
Abrokwah J.K. Lucero R. Hallmark J.A. Bernhardt B. 《Electron Devices, IEEE Transactions on》1997,44(7):1040-1045
Submicron p-channel (Al,Ga)As/(In,Ga)As HIGFETs have been optimized for application to high-performance complementary GaAs circuits. Major issues with submicron and deep submicron (Lg⩽0.5-μm) P-channel HIGFETs have been the severe short-channel effects, such as high subthreshold leakage currents and high output conductances. With optimization of the p-type self-aligned implant schedule, control of impurity contamination at the substrate/buffer interfaces and increase of the resistivity of the unintentionally-doped GaAs buffers, high-performance submicron devices have been realized. Typically, 0.5-μm P-HIGFETs yielded room temperature transconductances of 90 mS/mm, drain currents at Vgs =Vds=-1.5 V of 63 mA/mm, and subthreshold leakage currents near 1 nA. Subthreshold slope of 90 mV/decade and output conductances under 5 mS/mm were realized 相似文献
2.
Transconductance as high as 676 mS/mm at 300 K was observed to 0.7×10-μm2 n-channel devices (HIGFETs) made on epilayers with Al0.3Ga0.7As insulator thickness of 200 Å and In0.15Ga0.85As channel thickness of 150 Å. An FET K value (K =W g U ε/2aL g) as large as 10.6 mA/V 2 was also measured from another device with transconductance of 411 mS/mm. The high K values are achieved under normal FET operation without hole-injection or drain-avalanche breakdown effects. These results demonstrate the promise of pseudomorphic (Al,Ga)As/(In,Ga)As HIGFETs for high-performance circuit applications 相似文献
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陈培杖 《固体电子学研究与进展》1987,(4)
采用n-(AI,Ga)As/GaAs异质结构材料制作的高电子迁移率晶体管(HEMT)在微波与超高速器件中已逐步成熟,并已开始出现实用化产品。 本简讯首次报导采用汽相外延方法在半绝缘GaAs衬底上生长N-GaAs/(I,Ga八s异质结构材料制作的HEMT,并已证实器件在低温下未出现陷附中心造成的异常。(国外均采用MBE生长的材料)。 所用材料结构为半绝缘GaAs衬底上汽相外延约1卜m In人a1.仲s层(X=0.15)及o.2~0.3urn N-GaAs层,(In,Ga八s层不掺杂,而GaAs层掺杂浓度约 5 x 10‘”cm-‘。为研制HEMT,采用厚度监控技术使顶部N-GaAs层减薄至1000A以内。… 相似文献
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采用低压金属有机化学气相沉积(LP-MOCVD)技术,在InP衬底上外延生长In0.82Ga0.18As.研究生长温度对In0.82Ga0.18As表面形貌、结晶质量和Ⅲ族源铟镓比的影响.扫描电子显微镜观察样品的表面形貌.X射线衍射用于表征材料的组分和结晶质量.结果表明,生长温度强烈地影响In0.82Ga0.18As材料的表面形貌和结晶质量.样品的表面形貌随生长温度的增加由典型的2D生长模式过渡到3D生长模式.X射线衍射曲线半峰全宽为1224、1454、2221、2527 S,分别对应于生长温度为410、430、450、470℃四个样品.此外,Ⅲ族源铟镓比值也随生长温度的增加从0.42增大到4.62. 相似文献
6.
Zhao Zhen D. A. Bedarev B. V. Volovik N. N. Ledentsov A. V. Lunev M. V. Maksimov A. F. Tsatsul’nikov A. Yu. Egorov A. E. Zhukov A. R. Kovsh V. M. Ustinov P. S. Kop’ev 《Semiconductors》1999,33(1):80-84
The optical properties of structures containing InGaAs quantum dots in GaAs and AlGaAs matrices grown by molecular-beam epitaxy
are investigated. It is shown that increasing the In content in the quantum dots has the effect of raising the energy of carrier
localization and increasing the energy distance between the ground state and the excited states of carriers in the quantum
dots. An investigation of the influence of postgrowth annealing on the optical properties of the structures shows that the
formation of vertically coupled quantum dots and the use of a wide-gap AlGaAs matrix enhances the thermal stability of the
structures. Moreover, high-temperature (830 °C) thermal annealing can improve the quality of the AlGaAs layers in structures
with vertically coupled InGaAs quantum dots in an AlGaAs matrix. The results demonstrate the feasibility of using postgrowth
annealing to improve the characteristics of quantum dot lasers.
Fiz. Tekh. Poluprovodn. 33, 91–96 (January 1999) 相似文献
7.
Anthony P. Zilko J. Pawlik J. Swaminathan V. Hartman R. 《Quantum Electronics, IEEE Journal of》1982,18(7):1094-1100
Device characteristics of double heterostructure lasers with Al0.4 Ga0.6 As confinement layers and GaAs0.99 Sb0.01 active layers are presented. Average emission wavelengths have been increased from 0.87 μm for undoped active layers to 0.88 μm for2 times 10^{17} cm-3Ge doped active layers with a "wash" melt preceding the growth of the active layer and to 0.89 μ for1 times 10^{18} cm-3Mg doped active layers grown following a "wash" melt. Threshold currents for lasers from 21 wafers are examined for several growth conditions and compared with Al0.08 Ga0.92 As active layer devices. Device resistance, external quantum efficiency, device degradation, and pulsed and CW threshold currents as a function of temperature are also discussed. 相似文献
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A reduction in indium incorporation during the MBE growth of In(Al,Ga)As at moderate temperatures has been observed by RHEED oscillations and confirmed by X-ray diffractometry. The cause is believed to be surface segregation which can result in an under-estimate of the indium flux calculated from InAs RHEED oscillations, and the growth under non-optimum conditions of In-deficient In(Al,Ga)As with poor morphology.<> 相似文献
10.
B. C. Tousley S. M. Mehta A. I. Lobad P. J. Rodney P. M. Fauchet P. Cooke 《Journal of Electronic Materials》1993,22(12):1477-1480
A femtosecond, tunable color center laser was used to conduct degenerate pump-probe transmission spectroscopy of thin film
low temperature grown molecular beam epitaxy In0.53Ga0.47As samples. Low temperature molecular beam epitaxy In0.53Ga0.47As exhibits a growth-temperature dependent femtosecond optical response when probed near the conduction band edge. Below Tg=250°C, the optical response time of the material is subpicosecond in duration, and we observed induced absorption, which
we suggest is due to the formation of a quasi-“three-level system”. 相似文献
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Sandall I.C. Smowton P.M. Hui-Yun Liu Hopkinson M. 《Quantum Electronics, IEEE Journal of》2007,43(8):698-703
The segmented contact technique has been used to study the effects on nonradiative recombination of stacking multiple quantum-dot layers. As the number of stacked layers is increased a shift in the balance of dots in the bimodal dot distribution is observed due to a reduction in the number in the smaller dot size subset. This is attributed to an increase in the density of defect islands, as the number of layers is increased, that preferentially take material from the smaller dots, and lead to an increased level of nonradiative recombination per layer at low injection level. A second nonradiative process is apparent at higher injection level, which is related to the population of the small dot size subset. Spontaneous radiative efficiency was improved in a five-layer sample where the large to small dot size energy separation and relative density of the large dot size subset were increased. 相似文献
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G. B. Galiev S. S. Pushkarev I. S. Vasil’evskii E. A. Klimov A. N. Klochkov P. P. Maltsev 《Semiconductors》2014,48(1):63-68
The results of studies of the effect of GaAs (100) substrate misorientation on the electrical parameters and surface morphology of high electron mobility In0.7Al0.3As/In0.75Ga0.25As/In0.7Al0.3As/GaAs nanoheterostructures are reported. Using molecular-beam epitaxy, two identical structures with a stepped compositional profile of the metamorphic In x Al1 ? x As (Δ x = 0.05) buffer are grown on substrates of two types: a singular GaAs substrate with the orientation (100) ± 0.5° and a GaAs (100) substrate misoriented by (2 ± 0.5)° in the $\left[ {0\bar 1\bar 1} \right]$ direction. It is found that, in the case of the misoriented substrate, the concentration of the two-dimensional electron gas is ~40% higher. Broadening of the photoluminescence spectra and a shift of the peaks to lower photon energies, as experimentally observed in the case of the misoriented substrate, are attributed to the increased roughness of the heterointerfaces and strengthened fluctuations of the quantum-well width. 相似文献
15.
Injected carriers were found to reduce the dielectric constant of the active layer by the unexpectedly high value of 0.4. This is a factor of approximately four greater than measured for GaAs/(Ga, Al)As lasers and also higher than other reported values for (In,Ga)(As,P) lasers operating at a wavelength of 1.6 ?m. The technique employed was the observation of the spectral shift of individual Fabry-Perot modes of oxide insulated stripe lasers down to very low currents below threshold. 相似文献
16.
Photoluminescence (PL) was investigated as functions of the excitation intensity and temperature for a coupling surface quantum dots (SQDs) structure which consists of one In0.3Ga0.7As SQDs layer being stacked on multi-layers of In0.3Ga0.7As buried quantum dots (BQDs). Accompanied by considering the localized excitons effect induced by interface fluctuation, carrier transition between BQDs and SQDs were analyzed carefully. The PL measurements confirm that there is a strong carrier transition from BQDs to SQDs and this transition leads to obvious different PL characteristics between BQDs and SQDs. These results are useful for future application of SQDs as surface sensitive sensors. 相似文献
17.
The operation of (In,Ga)As quantum well lasers prepared on [112]-oriented GaAs substrates is reported. Threshold current densities as low as 187 A/cm2 for a 1.57 mm-long device have been obtained under pulsed-mode operation. The demonstration of laser action in a heterostructure grown on the [112]-oriented substrate is important for the design of blue-green light emitters by second harmonic generation 相似文献
18.
We determine the reduced mass of heavy-hole exciton and the heavy-hole in-plane mass for a series of (In, Ga)As/GaAs strained layer quantum wells using the magnetoluminescence measurements of the exciton ground state and the modified perturbation approach. In the theoretical calculation of the magnetoexciton ground state, the exciton reduced mass is considered as an adjustable parameter, and two variation parameters are used in the unperturbed wave function which is expressed in terms of subband wave functions in the growth axis and the product of two-dimensional hydrogen and oscillatorlike wave functions for the in-plane component. We take into account the energy dependence of transverse and in-plane electron masses in the two-band effective mass approximation. The electron effective mass decreases as either quantum-well width or indium composition increases, and so does the heavy-hole in-plane mass down to the value at the decoupling limit (mhh, p = 0.11m0). 相似文献
19.
电流密度分布对GaAs/GaAlAs条形激光器的瞬态温度特性的影响 总被引:1,自引:0,他引:1
本文将电流密度的侧向分布考虑到热传导模型中去,对一般条形半导体激光器的体内瞬态温度分布进行了计算,同时,利用光谱法对一些条形激光器的瞬态温度进行了实验测量.计算结果同测量结果一致. 相似文献
20.
《Electron Device Letters, IEEE》1981,2(2):50-52
Double-heterostructure injection lasers with additions of 1% Sb to the GaAs active layer have been found to have significantly improved reliability compared to lasers with binary GaAs active layers. Lasers with extrapolated room temperature median lifetimes of 105hours have Ga(As,Sb) active layers that are lattice matched to the Al0.4 Ga0.6 As confinement layers. Furthermore, the addition of Sb to the LPE active layer growth melt apparently improves the initial nucleation and growth uniformity of the active layer. 相似文献