Radio-Frequency (RF) losses on High-Resistivity Silicon (HRS) substrates were studied for several different surface passivation layers comprising thin-films of SiC, SiN and SiO₂ In many combinations, losses from conductive surface channels were reduced and increasing the number of interfaces between thin-films was found to be beneficial. In some cases the surface losses were completely eliminated. For example, with plasma-enhanced chemical-vapor deposition (PECVD) α-SiC layers up to a few tens of nm thick and exposed to nitridation or SiN growth at 850°C to form a SiC:N interface layer, values for the total losses of 1.6 dB/cm were achieved. Analysis of these layers was performed by using temperature dependent measurements of the RF losses on Coplanar Waveguides (CPWs), the capacitance-voltage characteristics and the sheet resistance along the Si surface. The overall results can be explained by assuming that the thin-films are so defected that they allow vertical current paths to highly-resistive interface layers where both fixed and mobile charge can be stored. ... Read more

In this work, we present the results of integrated Ge detectors grown on a Si photonic platform for sensing applications. The detectors are fabricated on a passive photonic circuit for maximum coupling efficiency. Measurement results at 1300 nm wavelength show a responsivity of 0.2 A/W and very low dark current levels. For a voltage range between 0 and −10 V, the dark current is better than 0.1 nA which is crucial for highly sensitivity devices and applications, like Optical Coherence Tomography. ... Read more