Operation of silicon-germanium heterojunction bipolar transistors on silicon-on-insulator in extreme environments

Recently, several SiGe HBT devices fabricated on CMOS-compatible silicon on insulator (SOI) substrates (SiGe HBTs-on-SOI) have been demonstrated, combining the well-known SiGe HBT performance with the advantages of SOI substrates. These new devices are especially interesting in the context of extreme environments - highly challenging surroundings that lie outside commercial and even military electronics specifications. However, fabricating HBTs on SOI substrates instead of traditional silicon bulk substrates requires extensive modifications to the structure of the transistors and results in significant trade-offs. The present work investigates, with measurements and TCAD simulations, the performance and reliability of SiGe heterojunction bipolar transistors fabricated on silicon on insulator substrates with respect to operation in extreme environments such as at extremely low or extremely high temperatures or in the presence of radiation (both in terms of total ionizing dose and single effect upset).Ph.D.Committee Chair: Cressler, John D.; Committee Member: Papapolymerou, John; Committee Member: Ralph, Stephen; Committee Member: Shen, Shyh-Chiang; Committee Member: Zhou, Hao Mi

Analysis and Characterization of a SiGe BiCMOS Low Power Operational Amplifier

Integrated circuit design for space applications can require radiation immunity, cryogenic operation and low power consumption. This thesis provides analysis and characterization of a SiGe BiCMOS low power operational amplifier (op amp) designed for lunar surface applications. The op amp has been fabricated on a commercially available 0.35-micron Silicon-Germanium (SiGe) BiCMOS process. The Heterojunction bipolar transistors (HBT) available in the SiGe process have been used in this op amp to take advantage of the total ionizing dose (TID) irradiation immunity and superb cryogenic operation, along with PMOS devices that show better TID immunity than their NMOS counterparts. The key features of the op amp include rail-to-rail output voltage swing, low input offset voltage, high open-loop gain and low supply current. The characterization of op amp is done for extreme temperatures and the results demonstrate that the op amp is fully functional across the lunar surface temperature range of −180°C to +120°C. The wide temperature operation of this op amp is tested using different bias current techniques such as proportional-to-absolute-temperature current, constant current and constant inversion coefficient current sources to investigate optimal biasing strategies for BiCMOS analog design. In addition, the SiGe BiCMOS low power op amp provides lower power consumption with the same or better unity-gain bandwidth when compared to a CMOS op amp with similar circuit topology

Qualifying silicon-germanium electronics for harsh radiation environments

The objective of this thesis is to investigate the robustness of Silicon-Germanium Heterojunction Bipolar Transistors (SiGe HBTs) to radiation-induced damage. The work described in this document delves into both total ionizing dose (TID) and single-event effect (SEE) mechanisms. Background information is provided for the general operation of SiGe HBTs and basic radiation effects (generic and specifically for SiGe HBTs). Four unique investigations are covered in this work: the first two focus on TID effects for high dose environments and to investigate enhanced-low-dose-rate-sensitivity, and the latter two studies investigate advances in hardening SiGe HBT profiles and methods to conduct SEE experiments using pulsed-lasers in place of highly energetic ionized particles.Ph.D

On the effects of total ionizing dose in silicon-germanium BiCMOS platforms

The objective of the proposed research is to analyze the effects of total ionizing dose (TID) on highly scaled CMOS and Silicon-Germanium Heterojunction Bipolar Transistors (SiGE HBTs). TID damage is caused by a build-up of charge at sensitive Si-SiO₂ interfaces and may cause device or circuit failure. TID damage is due to an accumulation of radiation particle strikes seen in extreme environments, such as space.M.S

Silicon-Germanium Bipolar Technology for Enabling Cold-Capable, Radiation-Tolerant Electronics for Spacecraft

The objective of this research is to investigate the effect that low temperature has on the radiation effects on advanced silicon-germanium (SiGe) heterojunction bipolar transistor (HBT) for the application of deep-space exploration missions that are specifically classified as extreme low-temperature and highly radiation active environments, such as Jovian exploration missions. We designed a unique experimental testbed that enabled DC and RF measurements to be taken in situ at various temperature and radiation points. The experiment was conducted at the Jet Propulsion Laboratory (JPL) where low-temperature and radiation environments can be mimicked. We showed that while there is some radiation damage in base leakage current on the single transistor level, there is no observed damage due to total-ionizing dose (TID) in noise figure, linearity, or gain for a 2.4 GHz low-noise amplifier (LNA) that was irradiated at an ambient temperature of about 100 K up to 1 Mrad (Si). Furthermore, we confirmed the notion that radiation at lower temperatures yields less damage and showed why it is important to separate temperature-dependent performance with measurable radiation damage at different temperatures. We also took a simulation approach to determine whether single-event transients (SETs) get worse as a result of the device being in low ambient temperatures. For a single standalone device, the results show that the transient gets larger in magnitude but shorter in duration. However, the circuit results show that the effects of an SET get worse in some cases with low temperatures such as in the context of LNAs, but can also get better in other cases such as current-mode logic (CML) D-flip-flops.M.S

Silicon-germanium BiCMOS and silicon-on-insulator CMOS analog circuits for extreme environment applications

Extreme environments pose major obstacles for electronics in the form of extremely wide temperature ranges and hazardous radiation. The most common mitigation procedures involve extensive shielding and temperature control or complete displacement from the environment with high costs in weight, power, volume, and performance. There has been a shift away from these solutions and towards distributed, in-environment electronic systems. However, for this methodology to be viable, the requirements of heavy radiation shielding and temperature control have to be lessened or eliminated. This work gained new understanding of the best practices in analog circuit design for extreme environments. Major accomplishments included the over-temperature -180 C to +120 C and radiation validation of the SiGe Remote Electronics Unit, a first of its kind, 16 channel, sensor interface for unshielded operation in the Lunar environment, the design of two wide-temperature (-180 C to +120 C), total-ionizing-dose hardened, wireline transceivers for the Lunar environment, the low-frequency-noise characterization of a second-generation BiCMOS process from 300 K down to 90 K, the explanation of the physical mechanisms behind the single-event transient response of cascode structures in a 45 nm, SOI, radio-frequency, CMOS technology, the analysis of the single-event transient response of differential structures in a 32 nm, SOI, RF, CMOS technology, and the prediction of scaling trends of single-event effects in SOI CMOS technologies.Ph.D

Circuits Techniques for Wireless Sensing Systems in High-Temperature Environments

RÉSUMÉ Dans ce projet, nous proposons de nouvelles techniques d’intégration basées sur la technologie de nitrure de gallium (GaN). Ces techniques permettent de mettre en œuvre un système de transmission de données sans fil entièrement intégré dédié aux capteurs de surveillance pour des applications d'environnement hostile. Le travail nécessite de trouver une technologie capable de résister à l'environnement sévère, principalement à haute température, et de permettre un niveau d'intégration élevé. Le système réalisé serait le premier dispositif de transmission de données basé sur la technologie GaN. En plus de supporter les conditions de haute température (HT) dépassant 600 oC, le système de transmission sans fil attendu devrait fonctionner à travers une barrière métallique séparant le module émetteur du récepteur. Une revue de la littérature sur les applications en environnements hostiles ainsi que sur l'électronique correspondante a été réalisée pour sélectionner la technologie AlGaN/GaN HEMT (transistor à haute mobilité d'électrons) comme une technologie appropriée. Le kit de conception GaN500, fourni par le Conseil national de recherches du Canada (CNRC), a été adopté pour concevoir et mettre en œuvre le système proposé. Cette technologie a été initialement introduite pour desservir les applications radiofréquences (RF) et micro-ondes. Par conséquent, elle n'avait pas été validée pour concevoir et fabriquer des circuits intégrés analogiques et numériques complexes et son utilisation à des températures extrêmes n’était pas validée. Nous avons donc caractérisé à haute température des dispositifs fabriqués en GaN500 et des éléments passifs intégrés correspondants ont été réalisés. Ces composants ont été testés sur la plage de température comprise entre 25 et 600 oC dans cette thèse. Les résultats de caractérisation ont été utilisés pour extraire les modèles HT des HEMT intégrés et des éléments passifs à utiliser dans les simulations. En outre, plusieurs composants intégrés basés sur la technologie GaN500, notamment des NOT, NOR, NAND, XOR, XNOR, registres, éléments de délais et oscillateurs ont été mis en œuvre et testés en HT. Des circuits analogiques à base de GaN500, comprenant un amplificateur de tension, un comparateur, un redresseur simple alternance, un redresseur double alternance, une pompe de charge et une référence de tension ont également été mis en œuvre et testés en HT. Le système de transmission de données mis en œuvre se compose d'un module de modulation situé dans la partie émettrice et d'un module de démodulation situé dans la partie réceptrice.----------ABSTRACT In this project, we propose new integrated-circuit design techniques based on the Gallium Nitride (GaN) technology to implement a fully-integrated data transmission system dedicated to wireless sensing in harsh environment applications. The goal in this thesis is to find a proper technology able to withstand harsh-environments (HEs), mainly characterized by high temperatures, and to allow a high-integration level. The reported design is the first data transmission system based on GaN technology. In addition to high temperature (HT) environment exceeding 600 oC, the expected wireless transmission systems may need to operate through metallic barriers separating the transmitting from the receiving modules. A wide literature review on the HE applications and corresponding electronics has been done to select the AlGaN/GaN HEMT (high-electron-mobility transistor) technology. The GaN500 design kit, provided by National Research Council of Canada (NRC), was adopted to design and implement the proposed system. This technology was initially provided to serve radio frequency (RF) and microwave circuits and applications. Consequently, it was not validated to implement complex integrated systems and to withstand extreme temperatures. Therefore, the high-temperature characterization of fabricated GaN500 devices and corresponding integrated passive elements was performed over the temperature range 25-600 oC in this thesis. The characterization results were used to extract HT models of the integrated HEMTs and passive elements to be used in simulations. Also, several GaN500-based digital circuits including NOT, NOR, NAND, XOR, XNOR, register, Delay and Ring oscillator were implemented and tested at HT. GaN500-based Analog circuits including front-end amplifier, comparator, half-bridge rectifier, full-bridge rectifier, charge pump and voltage reference were implemented and tested at HT as well. The implemented data transmission system consists of a modulation module located in the transmitting part and a demodulation block located in the receiving part. The proposed modulation system is based on the delta-sigma modulation technique and composed of a front-end amplifier, a comparator, a register, a charge pump and a ring oscillator. The output stage of the transmitter is intended to perform the load-shift-keying (LSK) modulation required to accomplish the data transmission through the dedicated inductive link. At the receiver level, three demodulation topologies were proposed to acquire the delivered LSK-modulated signals

Design and characterization of BiCMOS mixed-signal circuits and devices for extreme environment applications

State-of-the-art SiGe BiCMOS technologies leverage the maturity of deep-submicron silicon CMOS processing with bandgap-engineered SiGe HBTs in a single platform that is suitable for a wide variety of high performance and highly-integrated applications (e.g., system-on-chip (SOC), system-in-package (SiP)). Due to their bandgap-engineered base, SiGe HBTs are also naturally suited for cryogenic electronics and have the potential to replace the costly de facto technologies of choice (e.g., Gallium-Arsenide (GaAs) and Indium-Phosphide (InP)) in many cryogenic applications such as radio astronomy. This work investigates the response of mixed-signal circuits (both RF and analog circuits) when operating in extreme environments, in particular, at cryogenic temperatures and in radiation-rich environments. The ultimate goal of this work is to attempt to fill the existing gap in knowledge on the cryogenic and radiation response (both single event transients (SETs) and total ionization dose (TID)) of specific RF and analog circuit blocks (i.e., RF switches and voltage references). The design approach for different RF switch topologies and voltage references circuits are presented. Standalone Field Effect Transistors (FET) and SiGe HBTs test structures were also characterized and the results are provided to aid in the analysis and understanding of the underlying mechanisms that impact the circuits' response. Radiation mitigation strategies to counterbalance the damaging effects are investigated. A comprehensive study on the impact of cryogenic temperatures on the RF linearity of SiGe HBTs fabricated in a new 4th-generation, 90 nm SiGe BiCMOS technology is also presented.Ph.D

Electronics and Packaging Intended for Emerging Harsh Environment Applications: A Review

ABSTRACT: Several industrial applications require specific electronic systems installed in harsh environments to perform measurements, monitoring, and control tasks such as in space exploration, aerospace missions, automotive industries, down-hole oil and gas industry, and geothermal power plants. The extreme environment could be surrounding high-, low-, and wide-range temperature, intense radiation, or even a combination of above conditions. We review, in this paper, the main leading applications that demand advanced technologies to fit the unconventional requirements of extreme operating conditions, discussing their main merits and limits compared to established and emerging technologies in this field, including silicon (Si), silicon on insulator (SOI), silicon germanium (SiGe), silicon carbide (SiC) as well as III–V semiconductors particularly the gallium nitride (GaN) semiconductor. In spite of successfully exceeding extreme conditions borders by developing advanced semiconductor devices dedicated for harsh environments, especially in high-temperature applications, the packaging challenges are still limiting the reliability of the developed technologies. Those challenges are examined in this review in terms of limitations and proposed solutions

A SiGe BiCMOS LVDS Driver for Space-Borne Applications

When designing an integrated circuit for use during an interstellar mission, certain precautions must be made. The electronics on any off-earth mission will be exposed to wide temperature swings and harmful radiation due to being outside of the Earth’s protective ionosphere. It is crucial that any data path present be immune to these detrimental effects. The introduction of galactic radiation can not only cause the onboard electronics to fail due to device degradation and single event latchup but can also lead to background radiation being coupled into the signal path as unwanted noise, degrading the signal to noise ratio. Unwanted noise can cause total failure by increasing the noise level and decreasing the signal to noise ratio below one or can cause errors such as single event upsets. The wide temperature swing can cause device degradation and eventually failure. This issue is commonly mitigated by the introduction of an environment chamber but such an enclosure adds unnecessary mass and typically requires a large amount of current to effectively keep the electronics in an Earth-like temperature. The large current implies high power dissipation which is an unnecessary strain on the battery and can shorten the lifetime of a mission where every kilowatt-hour is crucial to success. The solution to these two non-trivial obstacles is to design an electronic circuit such that it can operate in a wide range of temperatures and can withstand the galactic radiation that it will inevitably encounter during its mission’s lifetime. The following thesis will document the design, simulation, and testing of a Si-Ge Bi-CMOS low voltage differential signal driver for space borne applications