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- ItemHeteroepitaxy of group IV materials for future device application(Bristol : IOP Publ., 2023) Yamamoto, Yuji; Wen, Wei-Chen; Tillack, BerndHeteroepitxy of group IV materials (Si, SiGe, and Ge) has great potential for boosting Si-based novel device performance because of the possibility for strain, band gap/Fermi-level engineering, and applying emerging artificial materials such as a superlattice (SL) and nanodots. In order to control group IV heteroepitaxy processes, strain, interface, and surface energies are very essential parameters. They affect dislocation formation, interface steepness, reflow of deposited layers, and also surface reaction itself during the growth. Therefore, process control and crystallinity management of SiGe heteroepitaxy are difficult especially in the case of high Ge concentrations. In this paper, we review our results of abrupt SiGe/Si interface fabrication by introducing C-delta layers and the influence of strain on the surface reaction of SiGe. Three-dimensional self-ordered SiGe and Ge nanodot fabrication by proactively using strain and surface energies by depositing SiGe/Si and Ge/SiGe SL are also reviewed.
- Item240-GHz Reflectometer-Based Dielectric Sensor With Integrated Transducers in a 130-nm SiGe BiCMOS Technology(New York, NY : IEEE, 2021) Wang, Defu; Eissa, Mohamed Hussein; Schmalz, Klaus; Kampfe, Thomas; Kissinger, DietmarThis article presents a reflectometer-based on-chip dielectric sensor with integrated transducers at 240 GHz. The chip simplifies the measurement of a vector network analyzer (VNA) to sense the incident and reflected waves by using two heterodyne mixer-based receivers with a dielectric sensing element. Radio frequency (RF) and local oscillator (LO) submillimeter waves are generated by two frequency multiplier chains, respectively. Two back-to-back identical differential side-coupled directive couplers are proposed to separate the incident and reflected signals and couple them to mixers. Both transmission line and coplanar stripline transducers are proposed and integrated with reflectometer to investigate the sensitivity of dielectric sensors. The latter leads to a larger power variation of the reflectometer by providing more sufficient operating bands for the magnitude and phase slope of S11 . The readout of the transducers upon exposure to liquids is performed by the measurement of their reflected signals using two external excitation sources. The experimental dielectric sensing is demonstrated by using binary methanol–ethanol mixture placed on the proposed on-chip dielectric sensor in the assembled printed circuit board. It enables a maximum 8 dB of the power difference between the incident and reflected channels on the measurement of liquid solvents. Both chips occupy an area of 4.03 mm 2 and consume 560 mW. Along with a wide operational frequency range from 200 to 240 GHz, this simplified one-port-VNA-based on-chip device makes it feasible for the use of handle product and suitable for the submillimeter-wave dielectric spectroscopy applications.
- ItemDual-Band Transmitter and Receiver With Bowtie-Antenna in 0.13 μm SiGe BiCMOS for Gas Spectroscopy at 222 - 270 GHz(New York, NY : IEEE, 2021) Schmalz, Klaus; Rothbart, Nick; Gluck, Alexandra; Eissa, Mohamed Hussein; Mausolf, Thomas; Turkmen, Esref; Yilmaz, Selahattin Berk; Hubers, Heinz-WilhelmThis paper presents a transmitter (TX) and a receiver (RX) with bowtie-antenna and silicon lens for gas spectroscopy at 222-270 GHz, which are fabricated in IHP's 0.13 μm SiGe BiCMOS technology. The TX and RX use two integrated local oscillators for 222 - 256 GHz and 250 - 270 GHz, which are switched for dual-band operation. Due to its directivity of about 27 dBi, the single integrated bowtie-antenna with silicon lens enables an EIRP of about 25 dBm for the TX, and therefore a considerably higher EIRP for the 2-band TX compared to previously reported systems. The double sideband noise temperature of the RX is 20,000 K (18.5 dB noise figure) as measured by the Y-factor method. Absorption spectroscopy of gaseous methanol is used as a measure for the performance of the gas spectroscopy system with TX- and RX-modules.
- ItemHigh-performance SiGe HBTs for next generation BiCMOS technology(Bristol : IOP Publ., 2018) Rücker, Holger; Heinemann, BerndThis paper addresses fabrication aspects of SiGe heterojunction bipolar transistors which record high-speed performance. We previously reported fT values of 505 GHz, fMAX values of 720 GHz, and ring oscillator gate delays of 1.34 ps for these transistors. The impact of critical process steps on radio frequency performance is discussed. This includes millisecond annealing for enhanced dopant activation and optimization of the epitaxial growth process of the base layer. It is demonstrated that the use of a disilane precursor instead of silane can result in reduced base resistance and favorable device scalability.
- ItemSISSI-LO : Schlussbericht ; Berichtszeitraum: 01.07.2011 bis 31.10.2012(Hannover : Technische Informationsbibliothek (TIB), 2013) Herzel, Frank[no abstract available]