Alain Cappy - IEEE Xplore Author Profile

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In a context of the end of Moore's law, energy dissipation constitutes a real challenge. Among the new energy efficient paradigms for data processing, bio-inspired computing is very promising, moreover introducing cognitive characteristics. As applications at very high scale are addressed, the size and energy dissipation of both the neuron and synapse cells needs to be minimized. In this context, ...Show More
This work proposes an experimental demonstration of the stochastic resonance, a phenomenon widely observed in biology using a 65 nm CMOS artificial neuron. The stochastic resonance has been revealed through two different statistical studies. Moreover, when optimal, a signal to noise ratio at the output of the artificial neuron of 22.4 dB is achieved, for an ultra low power consumption, lower than ...Show More
We report a Monte Carlo study of the dynamic behavior of an InAlAs/InGaAs velocity modulation transistor (VMT) based on the topology of a double-gate high electron mobility transistor (DG HEMT), which is a HEMT with two opposite gates controlling the carrier flow through the conducting channel. In the VMT, the source and drain electrodes are connected by two channels with different mobilities, and...Show More
A comparison of the noise behavior of Double-Gate and Standard High Electron Mobility Transistors is established by means of Monte Carlo simulations. The intrinsic noise P, R, and C parameters are only moderately improved in the DG-device, but the extrinsic minimum noise figure NFmin reveals a significantly better extrinsic noise performance, more noticeable for higher frequencies due to the bette...Show More
In this paper, we succeed in fabricating ultra short 30 nm gate pseudomorphic high electron mobility transistors (HEMT) with excellent cutoff frequencies. Devices with smaller Schottky barrier layer exhibited a current gain cutoff frequency fT of 450 GHz and a simultaneous maximum oscillation frequency fMAX of 500 GHz. This performance can be attributed to the use of the two-step-recessed gate tec...Show More
The noise performance of InAlAs/InGaAs double-gate (DG) and standard high-electron-mobility transistors (HEMTs) is analyzed by means of an ensemble 2-D Monte Carlo simulator. The DG-HEMT is found to have a better noise behavior than the single-gate (SG) device. The results show a moderate decrease of the and noise parameters for the DG HEMT with respect to that of the SG device, since current fluc...Show More
The static and dynamic behavior of InAlAs/InGaAs double-gate high-electron mobility transistors (DG-HEMTs) is studied by means of an ensemble 2-D Monte Carlo simulator. The model allows us to satisfactorily reproduce the experimental performance of this novel device and to go deeply into its physical behavior. A complete comparison between DG and similar standard HEMTs has been performed, and devi...Show More
An ensemble 2D Monte Carlo simulator is employed to analyze the static and dynamic performance of InAlAs/ InGaAs double-gate high electron mobility transistors (DG-HEMTs) by comparing them with standard single-gate (SG) ones. Different gate length devices are analyzed in order to check the attenuation of short-channel effects expected in the DG-structures. The transconductance gm and the output co...Show More
We analyze the influence of the surface charge on the operation of ballistic T-branch junctions based on InAlAs/InGaAs layers by means of a semi-classical 2-D Monte Carlo simulator. For this sake we propose a new self-consistent model in which the local value of the surface charge is dynamically adjusted depending on the surrounding carrier density. We will show that the TBJ rectifying behavior, t...Show More
Dry etching of AlSb and Al0.80Ga0.20Sb has been performed by inductively coupled plasma/reactive ion etching based on a (Cl2:Ar) gas mixture without addition of BCI3. The dry etch process has been used to fabricate AlSb/InAs high electron mobility transistors isolated by a shallow mesa. Good DC/RF results, with extrinsic fT/fmax= 135/105 GHz, have been measured for a 2×50 μm HEMT with a gate lengt...Show More
InAs/AlSb HEMTs with gate lengths in the range 225-335 nm processed on the same wafer have been investigated with respect to DC and RF performance. While the magnitude of the transconductance gm was similar for all gate lengths, the shortest gate length HEMT exhibited the highest extrinsic maximum frequency of oscillation fmax and extrinsic current gain cut-off frequency fT of 115 GHz and 165 GHz,...Show More
New THz chip solid-state detectors and sources are waited for many applications. The idea of new sources and detectors, based on the oscillations of bidimensional plasma, was theoretically and experimentally demonstrated. We present technological process of nanometric devices dedicated to THz emission. In this structure, a MIM gate-source capacitance is integrated to HEMT to achieve the boundary c...Show More
The intrinsic static and dynamic performance of InAlAs/InGaAs double-gate high electron mobility transistors (DG-HEMTs) is studied by means of an ensemble 2D Monte Carlo simulator. Our model allows going deeply into the physical behavior of this novel device in comparison with similar standard HEMTs. Different gate lengths are analyzed in order to check the attenuation of short-channel effects exp...Show More
We report on the design, fabrication and characterization of 100nm T-gates In0.52Al0.48As/In0.53Ga0.47 As double-gate HEMTs (DG-HEMT) on InP substrate. In comparison with single gate conventional HEMT, maximum oscillation frequency (fmax) was increased by 30% when the DG-HEMT operate in simple gate command (DG-HEMT-SC) due to the reduction of short channel effects. On the other hand, in double-gat...Show More
A double Y-branch ballistic junction is proposed for rectification of signals up to 94 GHz. A nonlinear model is developed to predict the frequency dependence of its RF to DC conversion performances, and agrees very well with experiment. The model shows the importance of minimizing extrinsic parasitics when designing HF ballistic nanodevices.Show More
THz radiations present a great interest for applications in different fields ranging from telecommunications to sensors for biology and medicine. This paper reviews two new field effect devices especially suited for THz applications: double-gate HEMTs (DG-HEMT) and plasma wave transistorsShow More
This paper deals with the design of passive band-pass filters in thin film microstrip (TFMS) technology for millimeter-wave application in G-band frequency range. The filters to be designed are realized on a BCB-based technology. Quality of the design method as well as technological process has already been fully tested in W-band at 94-GHz. Thus, transposition to higher frequency is investigated a...Show More
The paper presents the state of the art and the future trends in the field of AlInAs/GaInAs/InP based nanometre devices, in particular ballistic T junctions and plasma wave transistors.Show More
In this letter, we demonstrate successful operation of 100-nm T-gates double-gate high electron mobility transistors with two separate gate controls (V/sub g1s/ /spl ne/ V/sub g2s/). These devices are fabricated by means of adhesive bonding technique using enzocyclocbutene polymer. The additional gate enables the variation of the threshold voltage V/sub th/ in a wide range from -0.68 to -0.12V whi...Show More
We have developed technology based on GalnAs/AIInAs for building ballistic devices working at room temperature. We present processes for ballistic devices (T-branch junctions (TBJs), Y-branch junctions (YBJs)). Then we present DC characterization of TBJs to show the transition from ballistic to ohmic transport at room temperature and also experimental results for Y-branch junctions (YBJs).Show More
This paper reports fabrication, DC and RF characterization of the In/sub 0.52/Al/sub 0.48/As/In/sub 0.53/Ga/sub 0.47/As double-gate HEMTs with sub-micron gate lengths. These devices have obtained a maximum extrinsic transconductance g/sub m/ of 2650 mS/mm with a corresponding drain current I/sub d/ equal to 310 mA/mm. This extrinsic transconductance is the highest value ever reported for any trans...Show More
100nm T-gates InP double-gate HEMTs (DG-HEMT) have been fabricated by use of transferred substrate technique. Theses devices are compared with standard single 100nm T-gate HEMT. The maximum extrinsic transconductance gm of DG-HEMT is two times higher than the HEMT one, and the extrinsic output conductance gd is significantly reduced with DG-HEMT. The combined high gm and low gd induced an extremel...Show More
Room temperature DC and broadband HF measurements of a double Y-branch junction are presented and discussed. Nonlinear DC characteristics of the devices at room temperature are observed and HF to DC conversion up to 20 GHz at room temperature is presented. Small-signal equivalent circuit of YBJ is proposed. The HF to DC conversion efficiency degradation is found to be due to parasitic crosstalk ca...Show More