共查询到20条相似文献,搜索用时 15 毫秒
1.
Wen-Chau Liu Lih-Wen Laih Cheng-Zu Wu Shiou-Ying Chen Jung-Hui Tsai 《Electron Device Letters, IEEE》1997,18(4):129-131
An interesting multiple negative-differential-resistance (MNDR) device, based on an AlGaAs-InGaAs-GaAs metal-insulator-semiconductor (MIS)-like structure, has been fabricated and demonstrated. Three and six switching phenomena have been observed at room temperature and -105°C, respectively. The impressive MNDR behaviors are believed to be caused by the sequential accumulation process of carriers at Inx Ga1-xAs subwells and the successive barrier lowering and potential redistribution effects. These effects yield the step by step enhancement of tunneling through the “insulated” AlGaAs barrier. It is known that, from experimental results, the temperature variation plays an important role on carriers transport and experimental current-voltage (I-V) characteristics 相似文献
2.
The mobility due to misfit dislocation scattering in n-type modulation doped Al0.3Ga0.7As/InxGa1-xAs/Al 0.3Ga0.7As quantum wells is discussed. Initially, the dislocations are modeled as an array of orthogonal charged lines. The scattering potential is introduced, including both the coulombic and piezoelectric components. The expression for the mobility limited by dislocation scattering is established, and the anisotropic characteristics of mobility and its variation with various material and device parameters are presented and discussed 相似文献
3.
Kim J.W. Chen C.W. Vogt T.J. Woods L.M. Robinson G.Y. Lile D.L. 《Photonics Technology Letters, IEEE》1993,5(9):987-989
The first results on low-power p-i-n diode modulator structures using strained multiple quantum wells (MQW's) of InGaAs/InGaP grown by gas-source molecular beam epitaxy (MBE) on GaAs are presented. A comparison of transmission, reflection, and photocurrent spectra for these nonresonant devices with those fabricated from InGaAs/GaAs indicates larger modulation, with a maximum change in reflection of >42% observed at 5-V bias at a wavelength of 0.96 μm 相似文献
4.
5.
Hir-Ming Shieh Wei-Chou Hsu Rong-Tay Hsu Chang-Luen Wu Tien-Shou Wu 《Electron Device Letters, IEEE》1993,14(12):581-583
A δ-doped GaAs/InGaAs/GaAs pseudomorphic high electron mobility transistor (HEMT) utilizing a graded In composition InGaAs channel grown by low-pressure metalorganic chemical vapor deposition was demonstrated. This structure had an extrinsic transconductance as high as 175 (245) mS/mm and a saturation current density a high as 500 (690) mA/mm at 300 (77) K for a gate length of 2 μm. The maximum transconductance versus gate bias extended over a broad and flat region of more than 2 V at 300 K. A low gate leakage current (<10 μA at -7 V) at 300 K was obtained 相似文献
6.
Lau C.L. Feng M. Schellenberg J. Brusen P. Lepkowski T. Hwang T. Ito C. 《Electron Device Letters, IEEE》1991,12(5):244-245
The authors report the 60-GHz noise performance of low-noise ion-implanted InxGa1-xAs MESFETs with 0.25 μm T-shaped gates and amplifiers using these devices. The device noise figure was 2.8 dB with an associated gain of 5.6 dB at 60 GHz. A hybrid two-state amplifier using these ion-implanted InxGa1-x As MESFETs achieved a noise figure of 4.6 dB with an associated gain of 10.1 dB at 60 GHz. When this amplifier was biased at 100% I dss, it achieved 11.5-dB gain at 60 GHz. These results, achieved using low-cost ion-implantation techniques, are the best reported noise figures for ion-implanted MESFETs 相似文献
7.
Ahmari D.A. Fresina M.T. Hartmann Q.J. Barlage D.W. Mares P.J. Feng M. Stillman G.E. 《Electron Device Letters, IEEE》1996,17(5):226-228
A self-aligned InGaP/GaAs heterojunction bipolar transistor with a compositionally graded InxGa1-xAs base has been demonstrated with fT=83 GHz and fmax=197 GHz. To our knowledge, these results are the highest reported for both parameters in InGaP/GaAs HBT's. The graded base, which improves electron transport through the base, results in a DC current gain and a cutoff frequency which are 100% and 20% higher, respectively, than that achieved by an identical device with a nongraded base. The high fmax results from a heavily doped base, self-aligned base contacts, and a self-aligned collector etch. These results demonstrate the applicability of InGaP/GaAs HBT's in high-speed microwave applications 相似文献
8.
An anisotype heterojunction field-effect transistor (A-HJFET) for GaAs digital integrated circuit applications is proposed. A thin, highly doped, strained InxGa1-xAs (x ⩽0.2) n-channel is employed for improved transconductance while a p+-GaAs cap is used to enhance the dynamic gate voltage range of the device. Prototype devices with 5-μm gate lengths show a maximum transconductance of 80 mS/mm at V ds=2 V and a forward gate bias voltage of up to +2 V without significant leakage current 相似文献
9.
《Electron Device Letters, IEEE》1999,20(11):548-550
This letter reports a new and high-performance InGaP/InxGa1-xAs high electron mobility transistor (HEMT) with an inverted delta-doped V-shaped channel. Due to the presence of V-shaped inverted delta-doped InGaP/InxGa1-x As structure, good carrier confinement and a flat and wide transconductance operation regime are expected. Experimentally, the fabricated device (1×100 μm2) shows a high gate-to-drain breakdown voltage of 30 V and a high output drain saturation current density of 826 mA/mm at VGS=2.5 V. The high transconductance expands over a very broad operation range with the maximum value of 201 mS/mm at 300 K. Meanwhile, the studied device exhibits a good microwave frequency linearity 相似文献
10.
Yong Sun Wei Zhang Shuang Han Ran An Xin-Sheng Tang Xin-Lei Yu Xiu-Juan Miao Xin-Jun Ma Xianglian Pei-Fang Li Cui-Lan Zhao Zhao-Hua Ding Jing-Lin Xiao 《半导体学报》2024,(3):76-83
Excitons have significant impacts on the properties of semiconductors.They exhibit significantly different properties when a direct semiconductor turns in to an indirect one by doping.Huybrecht variational method is also found to influence the study of exciton ground state energy and ground state binding energy in AlxGa1-xAs semiconductor spherical quantum dots.The AlxGa1-xAs is considered to be a direct semiconductor at AI concentration below 0.45,and... 相似文献
11.
Monolithic wide-band amplifiers have been demonstrated using AlGaAs/InxGa1-xAs/GaAs pseudomorphic two-dimensional electron-gas field-effect transistors. The amplifiers have yielded an 18.0 GHz bandwidth and a 41.8 dBΩ transimpedance gain with a feedback resistance of 100 Ω. In addition, the dependence of In mole fraction for an InxGa1-xAs channel layer on device and amplifier performance has been also investigated. The gm and the fT in a device, along with the bandwidth, the gain, and the noise performance in an amplifier, have improved as the In mole fraction is varied from 0 to 0.25 相似文献
12.
Ng G.-I. Pavlidis D. Jaffe M. Singh J. Chau H.-F. 《Electron Devices, IEEE Transactions on》1989,36(10):2249-2259
Strained In0.52Al0.48 As/InxGa 1-xAs (x >0.53) HEMTs (high electron mobility transistors) are studied theoretically and experimentally. A device design procedure is reported that is based on band structure and charge control self-consistent calculations. It predicts the sheet carrier density and electron confinement as a function of doping and thickness of layers. The DC performance at 300 K is presented. Wafer statistics demonstrate improvement of device characteristics with excess indium in the channel (g¯m, intr=500 and 700 mS/mm for x=0.60 and 0.65). Microwave characterization shows the f T improvement (f T=40 and 45 GHz for x =0.60 and 0.65, respectively) and the R ds limitations of the 1-μm-long-gate HEMTs 相似文献
13.
用宽度为300微微秒的电脉冲驱动质子轰击条形的Al_xGa_(1-x)As双异质结激光器,产生12微微秒光脉冲。并已经用来检测快速光电二极管的响应速率。 相似文献
14.
Chandra A. Garbinski P.A. Shah N.J. Kuo J.-M. Kopf R.F. Smith P.R. 《Electron Device Letters, IEEE》1990,11(7):306-308
Short-pulse drain current versus gate voltage transfer characteristics measured for modulation-doped HFETs (MODFETs) with four donor-layer-channel-layer combinations-(1) Al0.3Ga0.7 As-GaAs, (2) Al0.2Ga0.8As-GaAs, (3) Al0.3Ga0.7As-In0.2Ga0.8As, and (4) Al0.2Ga0.8As-In0.2 a0.8 As-are compared with the DC transfer characteristics. The measurements are relevant to high-speed switching in HFET circuits. Significant shifts in threshold voltage are observed between the DC and short-pulse characteristics for the structures with n+-Al0.3Ga0.7As donor layers, while the corresponding shifts for structures with n+-Al0.2Ga0.8As donor layers are relatively small or virtually nonexistent 相似文献
15.
Young-Jin Jeon Yoon-Ha Jeong Bumman Kim Young-Gi Kim Won-Pyo Hong Myung-Sung Lee 《Electron Device Letters, IEEE》1995,16(12):563-565
Si-delta-doped Al0.25Ga0.75As/InxGa1-xAs (x=0.15-0.28) P-HEMT's, prepared by LP-MOCVD, are investigated. The large conduction band discontinuity leads to 2-DEG density as high as 2.1×1012/cm2 with an electron mobility of 7300 cm2/V·s at 300 K. The P-HEMT's with 0.7×60 μm gate have a maximum extrinsic transconductance of 380 mS/mm, and a maximum current density of 300 mA/mm. The S-parameter measurements indicate that the current gain and power gain cutoff frequencies are 30 and 61 GHz, respectively, The RF noise characteristics exhibit a minimum noise figure of 1.2 dB with an associated gain of 10 dB at 10 GHz. Due to the efficient doping technique, the electron mobility and transconductance obtained are among the best reported for MOCVD grown P-HEMT's with the similar structure 相似文献
16.
The DX-center-related short-pulse threshold voltage shifts (SPTVS) in AlxGa1-xAs-based MODFETs is modeled using CBAND, a simulator that solves Poisson equations self-consistently with Schrodinger equations and donor statistics. Using values given in the literature for the DX energy level in AlxGa1-xAs this technique gives good agreement between measured and simulated SPTVS for Al0.3Ga0.7As/GaAs and Al0.3Ga0.7As/In0.2Ga0.8As MODFETs. Both simulation and experiment show that the use of Al0.2 Ga0.8As in the donor layer reduces the SPTVS relative to the structures using Al0.3Ga0.7As. However, the measured shifts at this composition are considerably lower than the simulated values, indicating a DX energy level that may be higher than the value extrapolated from the literature, possibly due to the existence of multiple trap levels. Despite this discrepancy, these results support the use of strained-channel layers and lower Alx Ga1-xAs compositions in MODFETs for digital and other large-signal applications requiring good threshold stability 相似文献
17.
Happy H. Bollaert S. Foure H. Cappy A. 《Electron Devices, IEEE Transactions on》1998,45(10):2089-2095
A numerical model describing the influence of InAs mole fraction on metamorphic HEMT structures (MM-HEMT) is proposed. The material properties are calculated using the Monte Carlo method, while the charge control law is calculated using a self-consistent solution of Poisson's and Schrodinger's equations. The modeling of the dc, ac, noise and high frequency performance of a device with 0.25-μm gate length is performed using the quasi-two-dimensional (Q2D) approach. This analysis shows that an InAs mole fraction of about 0.40 is an optimum composition for manufacturing high gain, low noise amplifiers. In this range of composition, the performance of MM-HEMT structures is similar to that obtained for lattice-matched HEMTs on InP substrates 相似文献
18.
Wen-Chau Liu Wen-Lung Chang Wen-Shiung Lour Kuo-Hui Yu Kun-Wei Lin Chin-Chuan Cheng Shiou-Ying Cheng 《Electron Devices, IEEE Transactions on》2001,48(7):1290-1296
A newly designed inverted delta-doped V-shaped GaInP/InxGa1-xAs/GaAs pseudomorphic high electron mobility transistor (PHEMT) has been successfully fabricated and studied. For a 1×100 μm2 device, a high gate-to-drain breakdown voltage over 30 V at 300 K is found. In addition, a maximum transconductance of 201 mS/mm with a broad operation regime for 3 V of gate bias (565 mA/mm of drain current density), a very high output drain saturation current density of 826 mA/mm, and a high DC gain ratio of 575 are obtained. Furthermore, good temperature-dependent performances at the operating temperature ranging from 300 to 450 K are found. The unity current gain cutoff frequency fT and maximum oscillation frequency fmax up to 16 and 34 GHz are obtained, respectively. Meanwhile, the studied device shows the significantly wide and flat gate bias operation regime (3 V) for microwave performances 相似文献
19.
The authors have grown In0.22Ga0.78As/AlAs resonant tunnelling diodes (RTDs) on relaxed InxGa1-x As buffers on GaAs substrates, which show the largest peak-to-valley current ratio (PVCR), 13:1, ever reported for GaAs-based RTDs. X-ray diffraction and photoluminescence (PL) studies confirm the composition and relaxation of the buffers. The intrinsic device performance is excellent despite the presence of some dislocations in the active layers. However, it appears that the relaxed buffers do add series resistance to the intrinsic device 相似文献
20.
The DC and microwave properties of In0.52Al0.48 Al/InxGa1-xAs (0.53⩽x ⩽0.70) heterostructure insulated gate field-effect transistors (HIGFETs) with a quantum well channel design are presented. DC and microwave transconductances (g m) are enhanced as the In content is increased in the InGaAs channel. An intrinsic microwave g m value of 428 mS/mm and a K -factor of 1140 mS/mm-V have been obtained for 1.0-μm gate length with the 65% In channel devices. The sheet charge density, drift mobility, transconductance, current-gain cutoff frequency (f T), and maximum oscillation frequency (f max) all show a continuous improvement up to 65% In content ( f T=22.5 GHz with 53% and f T=27 GHz with 65% In; the corresponding f max change is from 6.5 to 8 GHz). The device performance degrades as the In content is increased to 70%. DC and microwave characteristics show the presence of negative differential resistance (NDR) up to 2.7 GHz 相似文献