Lars Ohlsson

High transconductance self-aligned gate-last surface channel In 0.53 Ga 0.47 As MOSFET

In this paper we present a 55 nm gate length In0.53Ga0.47As MOSFET with extrinsic transconductance of 1.9 mS/µm and on-resistance of 199 Ωµm. The self-aligned MOSFET is formed using metalorganic chemical vapor deposition regrowth of highly doped source and drain access regions. The fabricated 140 nm gate length devices shows a low subthreshold swing of 79 mV/decade, which is attributed to the described low temperature gate-last process scheme.

Slot-Coupled Millimeter-Wave Dielectric Resonator Antenna for High-Efficiency Monolithic Integration

A readily mass-producible, flip-chip assembled, and slot-coupled III-V compound semiconductor dielectric resonator antenna operating in the millimeter-wave spectrum has been fabricated and characterized. The antenna has a 6.1% relative bandwidth, deduced from its 10 dB return loss over 58.8–62.5 GHz, located around the resonance at 60.5 GHz. Gating in the delay-domain alleviated the analysis of the complex response from the measured structure. The radiation efficiency is better than

High-Frequency Performance of Self-Aligned Gate-Last Surface Channel MOSFET

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Time-Domain System for Millimeter-Wave Material Characterization

dB in simulations fed from the on-chip coupling-structure, but reduced by 3.7 dB insertion loss through the measurement assembly feed. Antenna gain measurements show distortion in relation to the simulated pattern, which has a maximum gain of 6 dBi, mainly caused by interference from the electrically large connector used in the assembly. Mode degeneration in the utilized quadratic-footprint resonator was not seen to influence the performance of the antenna. The antenna is intended for on-chip integration and the fabrication technology allows scaling of the operation frequency over the complete millimeter-wave spectrum.

High-Frequency Performance of Self-Aligned Gate-Last Surface Channel In0.53Ga0.47As MOSFET

We have developed a self-aligned L_g = 55 nm In_0.53Ga_0.47As MOSFET incorporating metal-organic chemical vapor deposition regrown n⁺⁺ In_0.53Ga_0.47As source and drain regions, which enables a record low on-resistance of 199 Ωμm. The regrowth process includes an InP support layer, which is later removed selectively to the n⁺⁺ contact layer. This process forms a high-frequency compatible device using a low-complexity fabrication scheme. We report on high-frequency measurements showing f_max of 292 GHz and f_t of 244 GHz. These results are accompanied by modeling of the device, which accounts for the frequency response of gate oxide border traps and impact ionization phenomenon found in narrow band gap FETs. The device also shows a high drive current of 2.0 mA/μm and a high extrinsic transconductance of 1.9 mS/μm. These excellent properties are attributed to the use of a gate-last process, which does not include high temperature or dry-etch processes.

A 15-Gb/s wireless on-off keying link

Time-domain material characterization using a leaky lens antenna and an in-house fabricated millimeter-wave wavelet generator using III-V technology is investigated. The wavelet generator produces short high-frequency pulses and is connected to a wideband and nondispersive leaky lens antenna. A purely time-domain methodology is used to extract the complex permittivity of nondispersive and nonmagnetic materials. The permittivity is found from the phase delay and the amplitude mismatch introduced by the object at the carrier frequency of the pulse. The wide bandwidth of the wavelet is used to investigate frequency-dependent material properties. Measurement results from two dielectric slabs are illustrated. The time-domain methodology is verified by frequency-domain measurements and analysis.

RTD–MOSFET Millimeter-Wave Wavelet Generator

We have developed a self-aligned L_g = 55 nm In_0.53Ga_0.47As MOSFET incorporating metal-organic chemical vapor deposition regrown n⁺⁺ In_0.53Ga_0.47As source and drain regions, which enables a record low on-resistance of 199 Ωμm. The regrowth process includes an InP support layer, which is later removed selectively to the n⁺⁺ contact layer. This process forms a high-frequency compatible device using a low-complexity fabrication scheme. We report on high-frequency measurements showing f_max of 292 GHz and f_t of 244 GHz. These results are accompanied by modeling of the device, which accounts for the frequency response of gate oxide border traps and impact ionization phenomenon found in narrow band gap FETs. The device also shows a high drive current of 2.0 mA/μm and a high extrinsic transconductance of 1.9 mS/μm. These excellent properties are attributed to the use of a gate-last process, which does not include high temperature or dry-etch processes.

Monolithically-Integrated Millimetre-Wave Wavelet Transmitter With On-Chip Antenna

Bit-error rate measurements for ON-OFF keying modulation at multigigabit per second rates over a V-band wireless link are presented. Serial data-rates from 2.5 to 20 Gb/s were studied for a 231 -1 bit random sequence. Error-free data transfer over a 0.3-m link was achieved at up to 10 Gb/s. Acceptable bit-error rates, <; 10-5 and 10-3, were measured at up to 1.5 m for 10- and 15-Gb/s data-rate, respectively. The performance was achieved using a transmitter that consists of an integrated wavelet generator, whereas the receiver was built from off-the-shelf waveguide components. The results demonstrate that very high data-rates may be achieved using binary modulation and short symbols generated in an efficient V-band transmitter. The system is benchmarked against state-of-the-art transceiver systems with multigigabit per second data-rates.

RF and DC Analysis of Stressed InGaAs MOSFETs

We report on the fabrication of a self-aligned regrown In0.53 Ga0.47As metal-oxide-semiconductor field-effect transistor (MOSFET) and a resonant tunneling diode (RTD). The performance of these devices is demonstrated by integrating them in parallel with an inductive coplanar waveguide stub to form a highly energy-efficient 70-GHz wavelet generator. The fast switching and low on-resistance of the MOSFET make it possible to kick-start and rapidly quench this RTD-driven oscillator circuit, which produces 41-ps-short wavelets at 15 Gpulses/s, a peak output power of 7 dBm, and an energy consumption of 1.9 pJ/pulse.

Self-aligned gate-last surface channel In 0.53 Ga 0.47 As MOSFET with selectively regrown source and drain contact layers

An integrated millimeter-wave wavelet transmitter has been fabricated and characterized. It consists of a generator core on a co-designed compact monolithically-integrated antenna. The peak output equivalent isotropic radiated power has been measured to 11 dBm, in 80, 160, and 320 ps wavelets centred at 63.5 GHz. This corresponds to a power of 5 dBm radiated from the 6 dBi antenna. At a dc-supply of 1.45 V, the on-state power dissipation was estimated to 37 mW. The radiated wavelet-power over dc-dissipation conversion-efficiency is 9%.