S. Bollaert - IEEE Xplore Author Profile

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We investigate the development of on-wafer multiline Thru-Reflect-Line calibration kits to enable transistor characterization beyond 110 GHz. The final objective is to measure the S parameters of a HEMT having a very high cut-off frequency (up to THz range). A first kit design shows that the use of configurations suitable for the frequency bands used in the calibration will optimize the measuremen...Show More
We report a high maximum frequency of oscillation ( f max) and a current-gain cutoff frequency ( f T) of 800 and 260 GHz, respectively, with pseudomorphic high-electron mobility transistor (PHEMT), using an InGaAs/InAs composite channel and an asymmetric gate recess. This result was achieved with long gate length L G = 75 nm. The RF small signal equivalent circuit (SSEC) was extracted up to 110 GH...Show More
In this paper, we present a high maximum frequency of oscillation (fmax) and a current-gain cutoff frequency (fT) of 800 GHz and 260 GHz respectively with pseudomorphic high-electron mobility transistor (PHEMT), using a composite, InGaAs/InAs/InGaAs channel and an asymmetric gate recess. This result was achieved with long gate length LG = 75 nm. The noise performance has been explored until 110 GH...Show More
We report a high maximum frequency of oscillation ( fmax) and a current-gain cutoff frequency (fT).fmax/fT = 1.2 THz/220 GHz; at VDS=1V with pseudomorphic high-electron mobility transistor (PHEMT), using a composite, InGaAs/InAs channel and an asymmetric gate recess. This result was achieved with long gate length LG=75 nm. The gate-source distance was 0.5 μm, in the recessed region the asymmetric ...Show More
As we tend towards extremely scaled CMOS circuits, InAs material has potential to replace traditional Si technology[1]. High electron mobility achieved in this material can enable n-type MOSFET operation at lower voltage supply(Vdd). Another key point required for a very low Vdd operation is to reduce the MOSFET access resistance(Raccess). Many studies have been reported on that topic[2][3]. Howev...Show More
III-V Impact-ionization (II) metal-oxide-semiconductor FETs (I-MOSFETs) and tunnel FETs (TFETs) are being explored as promising devices to achieve the best behavior for low power logical circuits. To facilitate the design process of these devices from the physical point of view, a Monte Carlo (MC) model which includes impact ionization events and band-to-band tunneling is presented. Our MC simulat...Show More
In this study, InAs metal-oxide-semiconductor field effect transistors (MOSFETs) ultra-thin body (UTB) were fabricated with self-aligned method. 4 nm thick Al2O3 gate oxide was deposited by Atomic Layer Deposition (ALD) technique. Ni-alloyed ohmic contacts for n-type source and drain (S/D) regions were formed at low annealing temperature (250°C). For a MOSFET with a gate length (LG) of 150 nm, we ...Show More
In this study, InAs metal-oxide-semiconductor field effect transistors (MOSFETs) ultra-thin body (UTB) were fabricated with self-aligned method. 4 nm thick Al2O3 gate oxide was deposited by Atomic Layer Deposition (ALD) technique. Ni-alloyed ohmic contacts for n-type source and drain (S/D) regions were formed at low annealing temperature (250°C). We developed a special shape based on the vertical ...Show More
100 nm gate length InAlAs/InGaAs high electron mobility transistors (HEMTs) have been transferred onto polyimide flexible substrate. In our previous paper, high frequency capability was demonstrated despite the presence of kink effect. Cutoff frequencies fT and fmax were respectively 120GHz and 280GHz and similar to value obtained on rigid substrate. In this work, we have designed a specific buffe...Show More
We report on terahertz wireless communication experiments at 0.2 THz, using a commercial GaAs field-effect-transistor as detector. For the first time, we will present the transmission of pseudo-random bit sequence at 0.2 THz using this commercial transistor and demonstrate open eye-patterns up to 1.5 Gbps. This transistor is integrated into a machined horn, so that its sensitivity is improved to 1...Show More
In this paper, we report on high frequency performances of AlSb/InAs high electron mobility transistor (HEMT) with 120nm gate length at room temperature. The excellent combined cut-off frequencies fT/fmax of 290/335 GHz simultaneously obtained at drain bias of 0.36V is another demonstration of the ability of AlSb/InAs HEMT for high frequency operation with low-power consumption. Small-signal equiv...Show More
This paper reports the transfer of 100nm-gate length high electron mobility transistors onto plastic flexible substrate. The layers of transistors are grown epitaxially on indium phosphide (InP) bulk substrate. The transfer of these transistors onto polyimide substrate is realized by an adhesive bonding technique. High cut-off frequencies fT =120GHz, fmax=280GHz are demonstrated. These microwave p...Show More
We present lattice matched (LM) In0.53Ga0.47As MOSHEMT and pseudomorphic (PM) In0.75Ga0.25As MOSHEMT with gate-first process as well as their related post process annealing (PPA) effects in this paper. PM In0.75Ga0.25As MOSHEMT with 7nm In0.75Ga0.25As inserted channel promotes higher DC and RF performances due to higher electron mobility with higher indium content of the channel. MOSHEMT structure...Show More
In this paper, multi-gate In0.53Ga0.47As MOSFETs were fabricated with different numbers of gate-fingers (4, 8, and 16) using air-bridge technology. The gate oxide of 8nm Al2O3 was deposited by ALD (Atomic Layer Deposition). The device was fabricated by self-aligned method with the gate deposition at first. For MOSFET with the gate length of 100nm, we achieved a maximum drain current Id of 120mA/mm...Show More
To fulfill high-speed and low-power specifications for both logic and analog applications, III–V FETs with high-κ gate dielectric stack are especially appealing, in particular for their ability to operate under low power supply voltage. Using complementary tools such as a 2D Poisson-Schrödinger solver and a Monte Carlo device simulator, we assess the potentiality of several III–V MOSFET structures...Show More
In this paper, multi-gate In0.47Ga0.53As MOSFETs with different numbers of fingers (4, 8 and 16) and different gate length were fabricated by using air-bridge technology. The devices were made by self-aligned method with gate deposition at first. For MOSFET with a gate length of 100nm, a maximum drain current of 120mA/mm, and a maximum transconductance of 75mS/mm were achieved at room temperature....Show More
In this paper, we present the noise measurement results of InAs/AlSb HEMTs at room temperature under very low drain bias (100mV) at 30GHz. Under these dc bias conditions the transistor exhibit NFmin=1.56 dB and Gass=5.3dB @30 GHz for Pdc= 7.3μW/μm. These results are compared to our previous work and the great improvements observed open up the possibility to develop a 100mV electronics at room temp...Show More
In this paper, we present a set of characteristics (DC, ft, fmax, extrinsic and intrinsic parameters) of a 120 nm gate length InAs/AlSb high electron mobility transistor (HEMT) with a doping plane of Tellurium (Te) operating at room temperature (RT) and low power conditions. A cut-off frequency ft equal to 103 GHz has been achieved at 100 mV trough the reduction of gate-channel distance and the ch...Show More
We present in this paper, a study of Dc, RF and Noise characteristics of an industrial metamorphic HEMT (High Electron Mobility Transistor) operating under low voltage at cryogenic temperature. The results at 300K are compared with the obtained results at cryogenic temperature. Temperature decrease makes device characteristics improve. This improvements allow to expect to develop a low power cryog...Show More
This paper discusses 120nm AlSb/InAs HEMTs operating at ultra low drain. HEMT is fabricated with ohmic contact evaporation and Schottky T-gates realization. A deep mesa isolation is used to remove completely the buffer leading to air-bridge gate.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
In this paper, a 200 nm n-channel inversion-type self-aligned In0.53Ga0.47As MOSFET with a Al2O3 gate oxide deposited by Atomic Layer Deposition (ALD) is demonstrated. Two ion implantation processes using silicon nitride side-wall are performed for the fabrication of the n-type source and drain regions. The 200 nm gate-length MOSFET with a gate oxide thickness of 8 nm features the transconductance...Show More
In this paper, we present a first full set of characteristics (dc, fT, fmax, and noise) of InAs/AlSb high-electron mobility transistors (HEMTs) operating under cryogenic temperature and low-power conditions. Those results are systematically compared and deeply analyzed at room temperature and 77 K. The characteristics improvement achieved at 77 K open up the possibility to develop ultralow-power c...Show More
We present technological bricks and concepts under study which could permit build up of future THz remote sensing systems. Critical issues regarding such systems mainly rely on the availability of sensitive and compact detectors together with powerful and versatile sources. Potential use of plasma waves in nano-transistor is presented which can be exploited for the realization of an efficient mixe...Show More