The Infona portal uses cookies, i.e. strings of text saved by a browser on the user's device. The portal can access those files and use them to remember the user's data, such as their chosen settings (screen view, interface language, etc.), or their login data. By using the Infona portal the user accepts automatic saving and using this information for portal operation purposes. More information on the subject can be found in the Privacy Policy and Terms of Service. By closing this window the user confirms that they have read the information on cookie usage, and they accept the privacy policy and the way cookies are used by the portal. You can change the cookie settings in your browser.
We present a microscopic analysis of electron noise in GaAs Schottky-barrier diodes under forward-bias conditions. An ensemble Monte Carlo simulator coupled with a one-dimensional Poisson solver is employed for the calculations. Current and voltage operation modes are applied separately, so that we provide both the microscopic origin and the spatial location of the noise sources. The coupling between...
Using only a few numerical calculations, we give the analytical current-voltage and charge-voltage characteristics valid for any PBT. The highest unity current gain frequency (fT) corresponding to the current technology is on the order of 30 GHz ; nevertheless, the oscillation frequency can be higher than 100 GHz.
We present a comparative study, at 300 K and at low longitudinal field, of the DC characteristics and the low-frequency noise in the drain current of GaAs/AlGaAs MODFETs which, ideally, differ only by the doping mode of the AlGaAs layer. The higher l/f-like noise in the δ-doped structure is consistent with our previous suggestion that charge fluctuations under the gate contribute significantly to...
In this paper, a Ga0.51In0.49P/GaAs insulated-gate inverted-structure HEMT (I2HEMT) was fabricated and investigated. It showed negligible deep-trap effect at low temperatures due to the low DX centers in GaInP. High drain-to-source breakdown voltage (10V) was obtained by using the GaInP insulated layer.
This paper describes a novel electronic device using a two dimensional electron gas produced by the strain-induced electric field in [111] growth-axis Al0.35Ga0.65As/In0.2Ga0.8As/GaAs strained layer structure without the necessity of modulation doping. Two dimensional densities greater than 1011 cm-2 were observed both at room temperaure and 77??K. A field effect tranistor using this strain-layer...
A review is given of the critical design features in Heterojunction Bipolar Transistors (HBTs) which are important in their application to large signal analogue circuits and high efficiency microwave power modules. The review is illustrated with recent achievements in the design of HBT devices and circuits and the systems applications which are driving their development.
The HBTs used in this study were grown by OMVPE. The base was carbon doped to 3??1019 cm??3 with a thickness of 500A. Several 3????10?? HBTs were biased at Ic=2,4 and lOmA (VCE=2V) and maintained at TA=125??C. Based on 1000 hours of operation at 125??C , Ic=2mA is safe, 4mA is marginal and 10mA is fatal.
A new GaAlAs-GaInP-GaAs HBT technology has been developed to benefit from the GaInP-GaAs heterojunction properties and from the etching selectivity between GaInP and GaAs. The multilayer structures are grown by CBE. A 2:1 Multiplexer and a Laser Driver operating at 5.6 GBit/s and 7 GBit/s respectively have been demonstrated for the first time in this material system.
The interest of AlGaAs/InGaAs/GaAs heterostructures for the realization of Hall effect magnetic sensors with a high sensitivity and a low thermal drift has been investigated. The physical phenomena responsible for the thermal drift of the Hall sensitivity were reviewed and investigated using a set of test devices with well-controlled structure parameters. These results were used to optimize the structure...
Performance of the surface acoustic wave (SAW) interdigital transducer (IDT) with doubled Al electrodes fabricated on GaAs wafers with submicrometre n-GaAs epitaxial layers has been investigated. Novel modes of linear as well as nonlinear operation of the transducer has been observed. The operation of electronic controllable SAW devices has been demonstrated which confirms possibility of creation...
Two-dimensional simulations of the impact of beryllium diffusion at the junction interface of AlGaAs/GaAs heterojunction bipolar transistors (HBTs) on the device performance are reported. It is shown that the current driving capability is greatly influenced by the redistributed profile of beryllium at the emitter-base junction due to outdiffusion. In addition, the dependence of the RF characteristics...
Two types of HEMT transistors with 0.2 μm gatelength have been fabricated: pseudomorphic (PM) on GaAs and lattice matched (LM) on InP. An extensive study of the DC and HF-characteristics shows the higher potential of the InP-based devices: extrinsic fT-values up to 141 GHz were obtained. The monolithic integration of the InP LM HEMT's is illustrated by the performance of a coplanar distributed amplifier.
A new ??-doped GaAs/InGaAs/GaAs pseudomorphic high electron mobility transistor(HEMT) utilizing a graded In composition in InxGa1-xAs quantum well grown by low-pressure metalorganic chemical vapor deposition (LP-MOCVD) was demonstrated. For a gate geometry of 2 ?? 100 ??m2, the studied new structure revealed superior extrinsic transconductance and saturation current density of 175 mS/mm and 500 mA/mm...
InAlAs/InGaAs HFETs having very high indium content (80 and 100%) in the channel have been fabricated on GaAs and electrically characterized. The extrinsic transconductance were 310 mS/mm (560 mS/mm at 77 K), and the saturation current were 700 mA/mm (600 mA/mm at 77 K) for an InAs channel. The value of fT and fmax for this device were measured to be 80 GHz and 50 GHz, respectively. The In0.8Ga 0.2...
Using two-and three dimensional analytical and numerical models, scaling limits derived from small-geometry degradation of subthreshold characteristics are compared for six different FET structures in bulk Si, SOI and GaAs technologies. For Si devices, the low impurity channel MOSFET can be scaled down to Lmin= 0.045??m and the dual gate SOI MOSFET to Lmin= 0.028??m. The GaAs MESFET can be scaled...
Set the date range to filter the displayed results. You can set a starting date, ending date or both. You can enter the dates manually or choose them from the calendar.