共查询到20条相似文献,搜索用时 15 毫秒
1.
Ren F. Chand N. Chen Y.-K. Pearton S. Tennant D.M. Resnick D.J. 《Electron Device Letters, IEEE》1989,10(12):559-561
High-performance AlGaAs/GaAs selectively doped heterojunction transistors (SDHTs) and 19-stage oscillators fabricated on silicon substrates are discussed. Epitaxial layers of AlGaAs/GaAs were grown by MBE on Si substrates. The mobility of two-dimensional electron gas (2DEG) in the SDHTs was as high as 53000 cm2/V-s at 77 K for a sheet charge density of 10×112 cm-2. For 1-μm-gate-length devices, maximum transconductances of 220 and 364 mS/mm were measured at 300 and 77 K, respectively, for the SDHTs. A minimum propagation delay time of 27 ps/stage at room temperature was obtained for a 19-stage direct-coupled FET logic ring oscillator with a power dissipation of 1.1 mW/stage. The propagation delay time was reduced to 17.6 ps/stage at 77 K. From microwave S-parameter measurements at 300 K, current gain and power gain cutoff frequencies of 15 and 22 GHz, respectively, were measured. These results are comparable to those obtained for SDHT technology on GaAs substrates 相似文献
2.
Yong-Xun Liu Plotka P. Suto K. Oyama Y. Nishizawa J. 《Electron Devices, IEEE Transactions on》1998,45(12):2551-2554
The I-V characteristics of ultrathin GaAs n++-p++ -n++ barrier structures with a 45 Å thick p++ layer grown by molecular layer epitaxy (MLE) have been measured at room temperature and 77 K. The tunneling probability for this structure has been calculated as a function of effective tunneling width. It was found that good agreement between experiment and calculation is obtained when the effective tunneling width is assumed to be 75 Å, which is much smaller than the depletion width about 190 Å measured by C-V method. This fact indicates that the depletion width approximation cannot be used to measure the exact tunneling width for ultrathin barrier devices 相似文献
3.
Jeong-Soo Lee Kwang-Ho Ahn Yoon-Ha Jeong Dae Mann Kim 《Electron Devices, IEEE Transactions on》1996,43(10):1665-1670
Characterized herein are quantum-well Hall devices in Si-delta-doped Al0.25Ga0.75As/GaAs and pseudomorphic Al0.25Ga0.75As/In0.25Ga 0.75As/GaAs heterostructures, grown by low-pressure metal organic chemical vapor deposition method. The Si-delta-doping technique has been applied to quantum-well Hall devices for the first time. As a result high electron mobilities of 8100 cm-2/V·s with a sheet electron density of 1.5×1012 cm-2 in Al0.25Ga0.75As/In0.25Ga0.75 As/GaAs structure and of 6000 cm-2/V·s with the sheet electron density of 1.2×1012 cm-2 in Al0.25Ga0.75As/GaAs structure have been achieved at room temperature, respectively. From Hall devices in Al0.25Ga0.75As/In0.25Ga0.75 As structure, the product sensitivity of 420 V/AT with temperature coefficient of -0.015 %/K has been obtained. This temperature characteristic is one of the best result reported. Additionally, a high signal-to-noise ratio corresponding to the minimum detectable magnetic field of 45 nT at 1 kHz and 75 nT at 100 Hz has been attained. These resolutions are among the best reported results 相似文献
4.
P. P. Lee R. J. Hwu L. P. Sadwick H. Balasubramaniam B. R. Kumar R. Alvis R. T. Lareau M. C. Wood 《Journal of Electronic Materials》1998,27(5):405-408
There is a significant interest in the area of improving high temperature stable contacts to III-V semiconductors. Two attractive
material systems that offer promise in this area are dysprosium phosphide/gallium arsenide (DyP/GaAs) and dysprosium arsenide/gallium
arsenide (DyAs/GaAs). Details of epitaxial growth of DyP/GaAs and DyAs/GaAs by molecular beam epitaxy (MBE), and their characterization
by x-ray diffraction, transmission electron microscopy, atomic force microscopy, Auger electron spectroscopy, Hall measurements,
and high temperature current-voltage measurements is reported. DyP is lattice matched to GaAs, with a room temperature mismatch
of less than 0.01% and is stable in air with no sign of oxidation, even after months of ambient exposure. Both DyP and DyAs
have been grown by solid source MBE using custom designed group V thermal cracker cells and group III high temperature effusion
cells. High quality DyP and DyAs epilayer were consistently obtained for growth temperatures ranging from 500 to 600°C with
growth rates between 0.5 and 0.7 μm/h. DyP epilayers are n-type with electron concentrations of 3 × 1020 to 4 × 1020 cm−3, room temperature mobilities of 250 to 300 cm2/V·s, and a barrier height of 0.81 eV to GaAs. DyAs epilayers are also n-type with carrier concentrations of 1 × 1021 to 2 × 1021 cm−3, and mobilities between 25 and 40 cm2/V·s. 相似文献
5.
GaAs static induction transistors (SIT) with 10-nm scale channel and with a 100-nm channel were fabricated with molecular layer epitaxy (MLE). Area-selective epitaxy of GaAs/AlGaAs/GaAs was used for the gate. Temperature dependence of current-voltage (I-V) characteristics of the 100-nm SIT indicates ballistic injection of electrons. In the 10-nm scale SIT, electrons are transported ballistically in the drain-side electric field. Direct tunneling is responsible for the transport through the potential barrier. It is indicated by the temperature dependence and by the electroluminescence spectrum. Electron transport in the 10-nm scale SIT is nearly scattering-free. The plausible estimation of the electron transit time is 2·10-14 s; the worst case estimation based on saturated drift velocity gives 1·10-13 s. It makes the ISITs suitable for THz applications. Multiple area-selective MLE GaAs regrowth was used as a tool for automatic definition of the channel length 相似文献
6.
7.
J. Gierak G. Ben Assayag M. Schneider C. Vieu J. Y. Marzin 《Microelectronic Engineering》1996,30(1-4):253-256
In this study, we propose a new characterisation method of the damage distribution using a GaAs/GaAlAs multi quantum well structure (MQW). Three quantum wells are used as high sensibility sensors, in relation to the damage created during the FIB irradiation through photoluminescence (P.L.) intensity measurements.
We have compared the effect of a Ga+ focused ion beam irradiation on the MQW structure, which was kept either at room temperature, or near the liquid nitrogen temperature (80 K) during the bombardment. The surface ion dose was kept constant at 1015 ions/cm2. No subsequent annealing was performed. Irradiated samples were characterised using low temperature (1.7 K) and spatially resolved photoluminescence experiments. 相似文献
8.
A microwave-compatible process for fabricating planar integrated resonant tunneling diodes (RTDs) is described. High-performance RTDs have been fabricated using AlxGa1-xAs/Iny Ga1-yAs/GaAs strained layers. Peak-to-valley current ratios (PVRs) of 4.8:1 with simultaneous peak current densities of 4×104 A/cm2 have been achieved at room temperature for diodes of area 9 μm2. Accurate measurements of reflection gain versus frequency between 1.5 and 26.5 GHz in the negative differential region indicate that the present technology is promising for millimeter-wave integrated circuits including self-oscillating mixers, frequency multipliers, and detectors 相似文献
9.
Gill D.M. Kane B.C. Svensson S.P. Tu D.-W. Uppal P.N. Byer N.E. 《Electron Device Letters, IEEE》1996,17(7):328-330
This letter describes the material characterization and device test of InAlAs/InGaAs high electron mobility transistors (HEMTs) grown on GaAs substrates with indium compositions and performance comparable to InP-based devices. This technology demonstrates the potential for lowered production cost of very high performance devices. The transistors were fabricated from material with room temperature channel electron mobilities and carrier concentrations of μ=10000 cm2 /Vs, n=3.2×1012 cm-2 (In=53%) and μ=11800 cm2/Vs, n=2.8×1012 cm-2 (In=60%). A series of In=53%, 0.1×100 μm2 and 0.1×50 μm2 devices demonstrated extrinsic transconductance values greater than 1 S/mm with the best device reaching 1.074 S/mm. High-frequency testing of 0.1×50 μm2 discrete HEMT's up to 40 GHz and fitting of a small signal equivalent circuit yielded an intrinsic transconductance (gm,i) of 1.67 S/mm, with unity current gain frequency (fT) of 150 GHz and a maximum frequency of oscillation (fmax) of 330 GHz. Transistors with In=60% exhibited an extrinsic gm of 1.7 S/mm, which is the highest reported value for a GaAs based device 相似文献
10.
Yoon-Ha Jeong Ki-Hawn Choi Seong-Kue Jo 《Electron Device Letters, IEEE》1994,15(7):251-253
Sulfide passivated GaAs MISFET's with the gate insulator of photo-CVD grown P3N5 films have been successfully fabricated. The device shows the drain current instability less than 22% for the period of 1.0 s ~1.0×104 s, due to excellent properties of sulfide treated P3N5/GaAs interface. The effective electron mobility and extrinsic transconductance of the device are about 1300 cm2/V·sec and 1.33 mS, respectively, at room temperature. To estimate the effects of sulfide treatment on P3N5/GaAs interfacial properties, GaAs-MIS diodes are also fabricated 相似文献
11.
Shey-Shi Lu Chung-Cheng Wu 《Electron Device Letters, IEEE》1992,13(9):468-470
Different emitter size, self-aligned In0.49Ga0.51 P/GaAs tunneling emitter bipolar transistors (TEBTs) grown by gas source molecular beam epitaxy (GSMBE) with 100-Å barrier thickness and 1000-Å p+(1×1019 cm-3) base have been fabricated and measured at room temperature. A small-signal current gain of 236 and a small common-emitter offset voltage of 40 mV were achieved without any grading. It is found that the emitter size effect on current gain was reduced by the use of a tunnel barrier. The current gain and the offset voltage obtained were the highest and lowest reported values to date, respectively, in InGaP/GaAs system heterojunction bipolar transistors (HBTs) or TEBTs with similar base dopings and thicknesses 相似文献
12.
Noda S. Kojima K. Mitsunaga K. Kyuma K. Hamanaka K. Nakayama T. 《Quantum Electronics, IEEE Journal of》1987,23(2):188-193
Ridge waveguide AlGaAs/GaAs distributed feedback lasers were fabricated by a two-step molecular beam epitaxy. A threshold current as low as 37 mA, which is the lowest ever reported, was obtained under a continuous wave condition at room temperature. The low threshold current is due to the larger coupling coefficient (91 cm-1) and a good current and optical confinement. The effects of the facet coatings were investigated and a high-power and a high-temperature operation was obtained. The polarization and the dynamic behavior were also investigated. 相似文献
13.
Cai S.J. Tang Y.S. Li R. Wei Y.Y. Wong L. Chen Y.L. Wang K.L. Mary Chen Schrimpf R.D. Keay J.C. Galloway K.F. 《Electron Devices, IEEE Transactions on》2000,47(2):304-307
The influence of proton irradiation (1.8 MeV, 1×1014 cm-2) on the properties of an AlxGa1-x N/GaN high electron mobility transistor (HEMT) is studied from current-voltage (I-V) and Raman scattering measurements as a function of rapid thermal annealing (RTA) temperature after irradiation. The I-V curves show that the saturation current (Ids) and the transconductance (gm) of the HEMT were seriously reduced by the irradiation. However, the dc characteristics of the HEMT could be mostly recovered by RTA at over 800°C 相似文献
14.
《Electron Device Letters, IEEE》1981,2(5):115-117
Refractory metal ohmic contacts to n-type GaAs have been developed using epitaxial Ge films and pulsed laser annealing. Laser annealing was carried out with a 22 ns pulse from a Q-switched ruby laser operating in the TEM00 mode. The specific contact resistivity of the contacts Ta/Ge and Ni/Ge on 2 × 1017cm-3dopes GaAs exhibited sharp minima as a function of laser energy density at 1 × 10-6Ω-cm2and 2 × 10-6Ω-cm2, respectively, which occurred near the melting point of the layered contacts. Auger electron sputter profiles revealed Ge migration into the GaAs surface after laser annealing at sufficient energy density to form ohmic contact. The contacts have applications to high temperature devices and to devices which experience high channel or contact temperatures, such as power FETs and TEDs. 相似文献
15.
The presence of traps in GaInP/GaAs and AlGaAs/GaAs HEMT's was investigated by means of low frequency noise and frequency dispersion measurements. Low frequency noise measurements showed two deep traps (E a1=0.58 eV, Ea2=0.27 eV) in AlGaAs/GaAs HEMT's. One of them (Ea2) is responsible for the channel current collapse at low temperature. A deep trap (Ea1'=0.52 eV) was observed in GaInP/GaAs HEMT's only at a much higher temperature (~350 K). These devices showed a transconductance dispersion of ~16% at 300 K which reduced to only ~2% at 200 K. The dispersion characteristics of AlGaAs/GaAs HEMT's were very similar at 300 K (~12%) but degraded at 200 K (~20%). The low frequency noise and the transconductance dispersion are enhanced at certain temperatures corresponding to trap level crossing by the Fermi-level. The transition frequency of 1/f noise is estimated at 180 MHz for GaInP/GaAs HEMT's and resembles that of AlGaAs/GaAs devices 相似文献
16.
Agahi F. Yang J.-X. Lau K.M. Yngvesson K.S. 《Electron Devices, IEEE Transactions on》1993,40(3):502-506
A combination of high mobility and high sheet carrier density in AlxGa1-xAs/GaAs two-dimensional electron gas (2DEG) elements was obtained by low-pressure organometallic vapor phase epitaxy (OMVPE). The sheet charge densities (n s) and mobilities (μ) at 77 K are 1.2×1012/cm2 and 90000 cm2/V-s for single-channel, and 2.0× 1012/cm2 and 64500 cm2/V-s for double-channel elements, respectively. Strong correlations between the photoluminescence spectrum of the AlxGa1-xAs layers and the 2DEG mobility were found. The 2DEG elements were used as mixers and detectors at millimeter wavelengths. Mixing at 94 GHz with a 1.7-GHz IF bandwidth and detection of signals as high as 238 GHz under a magnetic field were achieved with these devices 相似文献
17.
Nakajima S. Kuwata N. Shiga N. Otobe K. Matsuzaki K. Sekiguchi T. Hayashi H. 《Electron Device Letters, IEEE》1993,14(3):146-148
The fabrication and characterization of a double pulse-doped (DPD) GaAs MESFET grown by organometallic vapor phase epitaxy (OMVPE) are reported. The electron mobility of a DPD structure with a carrier concentration of 3×1018/cm3 was 2000 cm2/V-s, which is about 20% higher than that of a pulse-doped (PD) structure. Implementing the DPD structure instead of the conventional PD structure as a GaAs MESFET channel, the drain breakdown voltage, current gain cutoff frequency, and maximum stable gain (MSG) increase. The maximum transconductance of 265 mS/mm at a drain current density of 600 mA/mm, a current gain cutoff frequency of 40 GHz, and an MSG of 11 dB at 18 GHz were obtained for a 0.3 μm n+ self-aligned DPD GaAs MESFET 相似文献
18.
A Ga0.51In0.49P/GaAs DHBT with a heavily doped (1×1019 cm-3) narrow base (8 nm) grown by gas source molecular beam epitaxy and fabricated by simple wet chemical etching was demonstrated for the first time. A variable “N” shape negative differential resistance (NDR) controlled by base current was observed in the common-emitter current-voltage characteristics of this device at room temperature. A maximum peak-to-valley current ratio of 1×107 and a maximum current gain of 83 were achieved at room temperature. The largest peak-to-valley current ratio (1×107) achieved is, to our knowledge, the highest reported value to date. The NDR characteristics were explained by the base resistance effect 相似文献
19.
Capacitance-voltage (C-V) and current-voltage (I-V) measurements were used to study the thermal reaction of Pd/GaAs contacts
and Ni/GaAs contacts. The thickness of GaAs consumed by the metal/GaAs reaction during annealing was calculated from C-V analyses
and I-V analyses. For annealing temperatures below 350°C, the Schottky characteristics of the diodes were good but the electrical
junction moves into the GaAs after annealing. The amount of junction movement was calculated directly from our measurements.
The diffusion coefficients of Pd and Ni in GaAs at 300°C were estimated both to be around 1.2 × 1014 cm2/s. 相似文献
20.
《Electron Device Letters, IEEE》1984,5(11):496-499
Drain-to-source current for high gate voltages in AlGaAs/GaAs heterostructure FET's (HFET's) is found to depend on the electron saturation velocity in the AlGaAs layer. A simple model, which takes into account the current through the undepleted channel in the AlGaAs layer as a function of the electron saturation velocity in AlGaAs, is proposed for describing I-V characteristics of HFET's for high gate voltages. Using the model, effective electron saturation velocity in Alx Ga1-x As for different Al content levels has been obtained from the analysis of the present experimental results; 7 × 106cm/s for x = 0.24 and 3 × 106cm/s for x = 0.3 at a 4 × 1017cm-3doping concentration. 相似文献