Silicon Germanium Technology Research Articles

A first look at AS-ROC: a Si-Ge integrated chip readout for fast timing

Advances in timing detector technology require new specialized readout electronics. Applications demand below 10 ps time of arrival resolution and low power for a low repetition rate. A possible path to achieve O(10 ps) time resolution is an integrated chip using Silicon Germanium (SiGe) technology. Using DoE SBIR funding, Anadyne, Inc., in collaboration with UC Santa Cruz, has developed a prototype SiGe front-end readout chip optimized for low power and timing resolution. Two versions of the chip were produced with performance in simulation: a more power version with 10 ps resolution at 5 fC with 1.1 mW/channel, and a less power version with 10 ps resolution at 8 fC with 0.6 mW/channel.The chip was produced at Tower Semiconductor with 350 nm technology. The ASIC from the prototype run shows good performance: a rise time of 0.7–1 ns and 25 mV per fC response with RMS noise <1 mV. Simulation and results from the prototype will be reported in this paper.

Keynote Review of Latest Advances in Thermoelectric Generation Materials, Devices, and Technologies 2022

The last decade created tremendous advances in new and unique thermoelectric generation materials, devices, fabrication techniques, and technologies via various global research and development. This article seeks to elucidate and highlight some of these advances to lay foundations for future research work and advances. New advanced methods and demonstrations in TE device and material measurement, materials fabrication and composition advances, and device design and fabrication will be discussed. Other articles in this Special Issue present additional new research into materials fabrication and composition advances, including multi-dimensional additive manufacturing and advanced silicon germanium technologies. This article will discuss the most recent results and findings in thermoelectric system economics, including highlighting and quantifying the interrelationships between thermoelectric (TE) material costs, TE manufacturing costs and most importantly, often times dominating, the heat exchanger costs in overall TE system costs. We now have a methodology for quantifying the competing TE system cost-performance effects and impacts. Recent findings show that heat exchanger costs usually dominate overall TE system cost-performance tradeoffs, and it is extremely difficult to escape this condition in TE system design. In regard to material performance, novel or improved enhancement principles are being effectively implemented. Furthermore, in addition to further advancements in properties and module developments of relatively established champion materials such as skutterudites, several high performance ZT ≈≥ 2 new material systems such as GeTe, Mg3(Sb,Bi)2 have also been relatively recently unearthed and module applications also being considered. These recent advancements will also be covered in this review.

From Gunnplexer to MMIC: An Implementation on a Single Chip

The development of chip manufacturing processes over the last few decades led to smaller and smaller technology nodes with maximum transistor frequencies approaching the terahertz domain <xref ref-type="bibr" rid="ref1" xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">[1]</xref> . Consequently, it became feasible to integrate the different building blocks of millimeter-wave transceivers on the die, replacing several discrete elements in systems and leading to smaller form factors of sensor implementations. For example, in automotive radars, the development in silicon germanium (SiGe) technologies enabled integrated voltage-controlled oscillators (VCOs) fulfilling the demands for a signal source on the chip <xref ref-type="bibr" rid="ref2" xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">[2]</xref> . This led to cost-efficient radar systems including oscillators, mixers, and amplifiers on the die. A common problem with those monolithic microwave integrated circuits is that high-frequency connections from the chip to the printed circuit board have a large impact on the performance. Expensive substrates and sophisticated chip-to-board connections are necessary to address the losses that increase with the rise in frequency. As a result, on-chip antennas became very attractive in recent years <xref ref-type="bibr" rid="ref3" xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">[3]</xref> because they make those complex off-chip connections obsolete. Additionally, the size of antennas scales with the wavelength, which leads to a decrease in size with increasing frequencies. In automotive radar applications, the antennas are typically placed on the printed circuit board, as the operation frequencies of 76 GHz to 81 GHz would lead to a large chip area for the on-chip antennas; thus, an implementation is not worthwhile.

Equivalent Circuit Model Separating Dissipative and Radiative Losses for the Systematic Design of Efficient Microstrip-Based On-Chip Antennas

This article presents a comprehensive method to efficiently design capacitively enhanced resonant on-chip antennas using an equivalent circuit (EC) model instead of computationally demanding full-wave simulations. To systemize the design process by predicting the radiation efficiency, the input impedance, the current and voltage distributions, and the radiation pattern of the antenna based on an EC, a method to extract both dissipation and radiation mechanisms from full-wave simulation data is described and carried out. Based on this separation of loss mechanisms, an EC-based antenna optimization with respect to the radiation efficiency is conceivably possible. Additional to the EC, which enables this efficient antenna optimization and increases the physical insight in the radiation mechanism, an analytical estimation of key antenna parameters, as the resonant length, is presented. The results from the analytical calculations and the antenna parameters calculated using the EC model are compared with full-wave FDTD simulations and used to discuss the capabilities and limitations of the EC model. Finally, an on-chip antenna of the considered type operating at 290-300 GHz and manufactured with silicon-germanium technology is used to verify the full-wave antenna simulations and the presented approach in general.

STUDY OF A SOLAR CELL WITH A MULTILAYERED WINDOW BASED ON Si1-xGex USING AMPS-1D

The Silicon-Germanium (SiGe) technology, whose preliminary developments date from the mid-1980s and whose arrival on the market is recent, meets this joint need for economy and performance. In our days solar cells to thin films are increasingly used primarily because of their low cost. In recent decades the performance of these cells were significantly improved. In this work, we simulate solar cell base Si (1-x) Ge (X) multilayer window using software (AMPS-1D) to analyze some parameters. In particular, the properties of the window layer (thickness, doping, etc.) play a key role in the performance of the cell, and in order to optimize them, their influence on the photovoltaic quantities of the solar cell is studied. In order to highlight the importance of the deposition of a Si (1-x) Ge (X) type window layer on the Si (1-x) Ge (X) solar cells, a comparison between three cells , one with a window layer, the other with two layers windows and the third with three layers windows was made under 300 K and one sun (AM1.5) . The optimal solar cell was founding for the first window layer ( 100 nm ; x = 0.3 ) ,second window layer ( 80 nm ; x = 0.2 ) and the third window layer ( 60 nm ; x = 0.1 ) for 15.56 % optimal efficiency. This comparison led to the following conclusion: the multiplication of the cascade windows leads to a cell equivalent to a gradual window.

PERFORMANCE OF SIGE SOLAR CELL WITH BSF LAYER EFFECT OF TEMPERATURE AND WINDOW LAYER

The Silicon-Germanium (SiGe) technology, whose preliminary developments date from the mid-1980s and whose arrival on the market is recent, meets this joint need for economy and performance. In our days solar cells to thin films are increasingly used primarily because of their low cost. In recent decades the performance of these cells were significantly improved. In this work, we studied the temperature effect on performance forSiGe solar cell with BSF layer using software AMPS-1D to analyze some parameters. The temperature is one of most important effect and it plays a key on performance of solar cell.

A Model of a 30–50 GHz IC Chaotic Oscillation Source

In this paper, we propose and study a model of a source of ultra-wideband chaotic oscillations of the 30–50 GHz range in an IC version based on a 130-nm silicon-germanium technology.

Development of a new Front End electronics in Silicon and Silicon-Germanium technology for the Resistive Plate Chamber detector for high rate experiments

The upgrade of the Resistive Plate Chamber (RPC) detector, in order to increase the detector rate capability and to be able to work efficiently in high rate environment, consists in the reduction of the operating voltage along with the detection of signals which are few hundred μV small. The approach chosen by this project to achieve this objective is to develop a new kind of Front End electronics which, thanks to a mixed technology in Silicon and Silicon-Germanium, enhance the detector performances increasing its rate capability. The Front End developed is composed by a preamplifier in Silicon BJT technology with a very low inner noise (1000 e− rms) and an amplification factor of 0.3–0.4 mV/fC and a new kind of discriminator in SiGe HJT technology which allows a minimum threshold of the order of 0.5 mV. The performances of this kind of Front End will be shown. The results are obtained by using the CERN H8 beamline with a full-size RPC chamber of 1 mm gas gap and 1.2 mm thickness of electrodes equipped with this kind of Front End electronics.

A SiGe transceiver chipset for automotive radar applications using wideband modulation sequences

AbstractThis paper presents a W-band MIMO radar transceiver chipset for automotive applications, based on a Silicon Germanium technology. It consists of a reference VCO, operating at a center frequency of 38 GHz and a companion IC that comprises a complete millimeter-wave transceiver at 76 GHz. This chipset enables building multipurpose MIMO radar systems that can be scaled in terms of transmitter and receiver count. What makes this system innovative is the fact that it is able to handle more broadband signals than systems presented in current literature and is furthermore not limited to one modulation scheme. The chipset is capable of transmitting and receiving any signal waveform. The main goal of this work was to create a functional version of a VCO and a one-channel transceiver MMIC. Furthermore a demonstrator for a proof of concept was designed to test the MMICs on a system level. The realized VCO MMIC achieves a tuning frequency range of 6 GHz with a center frequency of 38 GHz and consumes 152 mW from a 3.3 V supply. The transceiver MMIC is fully functional and achieves a saturated output power of 11.5 dBm while drawing 670 mW from a 3.3 V supply.

Модель источника хаотических колебаний диапазона 30-50 GHz в интегральном исполнении

A model of the source of 30-50 GHz ultra-wideband chaotic oscillations based on 130 nm silicon-germanium technology is proposed and investigated.

Formation of Nanocrystalline Structures under Germanium and Indium Electrodeposition

The processes of electrodeposition of Ge and Ge–In from ammonia-tartrate solutions have been studied. The nature of interactions in thin-film systems obtained by germanium and indium codeposition has been investigated by means of potentiodynamic voltammetry in the inversion mode. The role of electrodesurface modification has been emphasized for deposition of a germanium film of a preset thickness from aqueous solutions. As was shown by the atomic force microscopy study, glossy films with a nanocrystalline structure had been formed. It has been established that, to develop silicon–germanium technologies, deposition of thin films must be performed from ionic liquids.

K-Band SiGe System-on-Chip Radiometric Receiver for Remote Sensing of the Atmosphere

System-on-chip (SoC) miniaturization of radiometric sensors could dramatically improve quantitatively the study of Earth’s atmosphere in the microwave- and millimeter-wave frequency regions, enabling cost and weight reductions both for ground- and space-based observation instruments. This paper reports the analysis, design, implementation, and experimental characterization of the first K-band SoC Dicke radiometric receiver implemented in a commercial silicon–germanium technology under Space evaluations. The radiometric receiver exhibits a responsivity of about 760 kV/W and a noise equivalent power of about 232 fW/ $\surd $ Hz at the center frequency of 25.75 GHz. For a bandwidth of 2.5 GHz, the system achieves a resolution of 9 K for a relatively short integration time (1 s), 2.8 K for a medium integration time (10 s), and 0.9 K for a relatively long integration time (100 s).

Use of Silicon-Germanium Technology for the Development of Active Microwave Units of Active Electronically Scanned Arrays

The possibility of using new technologies to develop active microwave units of transmit/receive modules is considered. A comparative analysis of technological processes for core chip implementation is given. The possible achievable parameters of the universal core chip for X-band SiGe technology are estimated.

Ultimate Pixel Based on a Single Transistor With Deep Trapping Gate

Simulation results are reported on the trapping MOS structure, which is a new metal insulator semiconductor pixel concept. Using a quantum well (QW) as a buried gate, I will show that this device is the ultimate design for photon sensitive pixels when pixel size is the criterion. The device reduces to only one transistor, which acts as a charge collecting device and amplifier and it is randomly addressable. I study here the device based on a silicon–germanium material couple, but the principle can be implemented with other materials. The photo-generated charge is collected by a buried gate based on a QW, and is able to selectively localize carriers that modulate the source–drain current in the readout mode. The device simulation is based on the quantum density gradient method, which had shown to give good results with respect to previous experimental studies. They are applied in the case of thin (20 nm) buried SiGe layers, which is comparable with an earlier structure using traps for charge retention. The simulation of this structure based on actual silicon germanium technologies is robust enough to assess the practical feasibility of the device. Downscaling to deep submicrometer sizes is possible with favorable consequences regarding the pixel’s sensitivity.

Ring coupling of on-chip submillimeter wave sources

An output power increasing approach of on-chip terahertz sources is described. This approach is consists of oscillators synchronization by combining its in ring structure. The influence of ring parameters and number of oscillators on the phase stability is theoretically studied out. The presented oscillator was fabricated on 350 nm silicon-germanium technology. The results of experimental studies of fabricated generator are also presented.

A SiGe 8–18-GHz Receiver With Built-In-Testing Capability for Self-Healing Applications

A wideband (8-18 GHz) built-in test receiver in silicon-germanium technology is presented. The receiver chain consists of a low-noise amplifier (LNA), an image-reject mixer, on-chip automatic gain control ring oscillator sources that are used to provide test signals of a predefined amplitude, and control circuitry in the form of digital-to-analog converters and data registers. Both the LNA and the mixer circuit blocks incorporate tuning knobs to enable tuning of RF metrics to ensure consistent performance and mitigate the negative effects of process, voltage, and temperature variations, aging, and damage from extreme environments such as ionizing radiation. A maximum post-healed gain greater than 30 dB, an image rejection ratio exceeding 30 dB, output third-order intercept point greater than 8 dBm, and noise figure less than 9 dB are obtained in measurement. An automated healing algorithm was developed and shown to be effective at improving the overall performance of the receiver. The receiver was fabricated in an 0.18- μm SiGe BiCMOS process with a peak fT of 150 GHz, and consumes 240-260 mA from a 4-V supply.

A Fully-Integrated 77-GHz UWB Pseudo-Random Noise Radar Transceiver With a Programmable Sequence Generator in SiGe Technology

This paper describes a fully-integrated 77-GHz ultra-wideband pseudo-random noise (PRN) radar transceiver in a Silicon-Germanium technology. The transceiver is equipped with a programmable pseudo-random binary sequence (PRBS) generator, which is realized in a current-mode logic topology and can be operated with a clock rate of up to 4.25 GHz to enable a range resolution of 3.5 cm. The signal generation unit is simplified by including a frequency multiplier to create a 76.5-GHz carrier signal from a single 4.25-GHz input, that is also used as a clock for the PRBS generator. The transceiver achieves a phase noise of -105.3 dBc/Hz at 1-MHz offset frequency, a transmit output power of 6.2 dBm, a receive gain of 24 dB and an input-referred 1-dB compression point of -14 dBm. Track&hold circuits included in the receive path allow the use of a sub-sampling technique to reduce the IF data rate down to 1 MHz. Radar measurements with two PRN transceivers with different primitive polynomials were done concurrently to show a fundamental function of the programmable PRBS generator. Radar measurements with the PRN and the frequency-modulated continuous-wave (FMCW) principles show comparable results and the PRN radar proves to be a real alternative to the FMCW radar.

Radiation Effects in SiGe Technology

Silicon-Germanium (SiGe) technology effectively merges the desirable attributes of conventional silicon-based CMOS manufacturing (high integration levels, at high yield and low cost) with the extreme levels of transistor performance attainable in classical III-V heterojunction bipolar transistors (HBTs). SiGe technology joins together on-die high-speed bandgap-engineered SiGe HBTs with conventional Si CMOS to form SiGe BiCMOS technology, including all the requisite RF passive elements and multi-level thick-Al metalization required for high-speed circuit design. Such an silicon-based integrated circuit technology platform presents designers with an ideal division of labor for realizing optimal solutions to many performance-constrained mixed-signal (analog + digital + RF) systems. The unique bandgap-engineered features of SiGe HBTs enable several key merits with respect to operation across a wide variety of so-called “extreme environments”, potentially with little or no process modification, ultimately providing compelling advantages at the circuit and system level, across a wide class of envisioned commercial and defense applications. Here we give an overview of this interesting field, focusing primarily on the intersection of SiGe HBTs, and circuits built from them, with radiation-intense environments such as space.

Buried Silicon-Germanium pMOSFETs: Experimental Analysis in VLSI Logic Circuits Under Aggressive Voltage Scaling

In this paper, the potential of Silicon-Germanium (SiGe) technology for VLSI logic applications is investigated from a circuit perspective for the first time. The study is based on experimental measurements on 45-nm SiGe pMOSFETs with a high- κ/metal gate stack, as well as on 45-nm Si pMOSFETs with identical gate stack for comparison. In the reference SiGe technology, an innovative technological solution is adopted that limits the SiGe material only to the channel region. The resulting SiGe device merges the higher speed of the Ge technology with the lower leakage of the Si technology. Appropriate circuit- and system-level metrics are introduced to identify the advantages offered by SiGe technology in VLSI circuits. Analysis is performed in the context of next-generation VLSI circuits that fully exploit circuit- and system-level techniques to improve the energy efficiency through aggressive voltage scaling, other than low-leakage techniques. Analysis shows that the SiGe technology has more efficient leakage-delay and dynamic energy-delay trade-offs at nominal supply, compared to Si technology. Moreover, it is shown that the traditional analysis performed at nominal supply actually underestimates the benefits of SiGe pMOSFETs, since the speed advantage of SiGe VLSI circuits is further emphasized at low voltages. This demonstrates that SiGe VLSI circuits benefit from aggressive voltage scaling significantly more than Si circuits, thereby making SiGe devices a very promising alternative to Si transistors in next-generation VLSI systems.

Dynamic chaos in the microwave range generated in SiGe-based autooscillatory structure

A chaotic microwave autooscillatory structure has been designed, implemented on a monolithic IC manufactured by 0.25-μm silicon-germanium technology, and studied. The experiments with the IC showed the possibility of generating stable chaotic oscillations in the 3–8-GHz range.