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A process for microelectronic technology is developed for integration of passive devices with existing active device technology for submillimeter wave and THz frequency range applications. Performances of a conductor-backed coplanar waveguide on BCB polymer and interconnecting via between ground planes are presented up to 67 GHz with a 50 Ω characteristic impedance and a BCB relative permittivity of 2.676.

Optical modulation in the O-Band using a Mach-Zehnder modulator in push-pull configuration is presented and experimentally demonstrated. Open eye diagrams at 25 GBps have been obtained with more than 8 dB extinction ratio with an active length of only 1 mm.

Silicon-based photonics has generated a strong interest in the last years, mainly for optical telecommunications and optical interconnects in microelectronic circuits and industrial breakthroughs have been even performed by companies like IBM, Luxtera, INTEL, and ST Microelectronics. The main future rationales are the reduction of photonic system costs, the increase of the number of functionalities on the same integrated chip by combining photonics and electronics, and the decrease of power consumption. During the DACINCT workshop, we will present recent results on ultrafast optical modulators based on carrier depletion effect and germanium photodetectors integrated in silicon on insulator (SOI) waveguides. Both optoelectronic devices have been fabricated on a CMOS 300mm platform. The achieved performances constitute a new milestone towards new generations of several Tb/s chips merging electronics and photonics.

We demonstrate a reduction of loss and group velocity dispersion (GVD) of THz plasmonic waveguides by using a low-loss thin flexible substrate. We present a numerical calculation of the effect of the substrate thickness on the GVD. We show experimentally low absorption and weak distortion of the propagated THz pulses along a THz plasmonic waveguide on a flexible 58μm-thick polyimide substrate.

We report the generation of continuous terahertz waves from microwave frequencies up to 2 THz obtained by photomixing two optical waves at 1.55-mum wavelengths in an optimized ion-irradiated In0.53Ga0.47As interdigitated photomixers. Output powers greater than 40 nW at 0.5 THz and 10 nW at 1 THz have been achieved. The optimum excitation conditions regarding optical power and bias voltage are discussed.

We measured the terahertz (THz) emission from heavy-ion irradiated In/sub 0.35/Ga/sub 0.47/As photoconductive (PC) antennas excited at 1550 nm. The In/sub 0.35/Ga/sub 0.47/As layer irradiated at 10/sup 12/ cm/sup -2/ shows a carrier lifetime shorter than 200 fs, a steady-state mobility of 490 cm/sup 2/V/sup -1/s/sup -1/, and a dark resistivity of 3.1 /spl Omega/cm. The spectrum of the electric field radiated from the heavy-ion irradiated In/sub 0.35/Ga/sub 0.47/As antenna extends beyond 2 THz. Comparative measurements performed on In/sub 0.35/Ga/sub 0.47/As PC antennas irradiated at 10/sup 11/ cm/sup -2/ and 10/sup 12/ cm/sup -2/ demonstrate the impact of the defect center scattering on the photo-excited carrier mobility.

Microwave and low frequency noise performance of buried channel SiGe HFETs fabricated on several strain relieved buffer (SRB) are presented. The impact of such SRB on microwave device noise performance is estimated by a proper noise de-embedding technique. The influence of device gate length on high microwave noise parameters is also discussed. High frequency noise properties measured in the 2.5-18 GHz frequency range are simulated means of the small signal equivalent circuit. Good agreement between measurement and modeling is obtained Furthermore, the low frequency noise properties for devices with different gate dimensions are discussed in order to predict further improvements on noise performance when shrinking the gate length below 100 nm.

A 3 dB bandwidth of 35 GHz at 1.31 /spl mu/m and 1.55 /spl mu/m wavelengths is reported for inter-digited germanium on silicon-on-insulator metal-semiconductor-metal photodetector with finger spacing of 500 nm.

Ion-irradiated InGaAs lattice-matched to InP has been explored in this work and used as the active layer of new photoconductors. Photoconductors with an ion-irradiated InGaAs layer of 0.3 /spl mu/m thickness have been fabricated and the samples were grown by metal organic vapor phase epitaxy lattice-matched to InP substrate. The InGaAs layers were irradiated either by 200 MeV heavy-ion (Au/sup +/) at fluences from 1/spl times/10/sup 10/ to 1/spl times/10/sup 12/ ions/cm/sup 2/ or by 1MeV light ion (H/sup +/) at fluences from 1/spl times/10/sup 13/ to 1/spl times/10/sup 15/ cm/sup 2/. Hall measurements have also been performed on ion irradiated InGaAs layers. We have shown that the ion irradiation of InGaAs layers provides subpicosecond carrier lifetime while preserving good electrical properties of the material. Ion-irradiated InGaAs is very promising for the fabrication of 1.55 /spl mu/m ultrafast sensitive photoconductors.

The high frequency and noise performances of n- and p-SiGe based MODFETs are reviewed. Their excellent HF and low noise behavior makes them well suited for RF mobile communications. We discuss their physical modeling, design optimization and self-heating effects.