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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
101

A Fully-differential Bulk-micromachined Mems Accelerometer With Interdigitated Fingers

Aydin, Osman 01 March 2012 (has links) (PDF)
Accelerometer sensors fabricated with micromachining technologies started to take place of yesterday&rsquo / s bulky sensors in many application areas. The application areas include a wide range from consumer electronics and health systems to military and aerospace applications. Therefore, the performance requirements extend form 1 &mu / g&rsquo / s to 100 thousand g&rsquo / s. However, high performance strategic grade MEMS accelerometer sensors still do not exist in the literature. Smart designs utilizing the MEMS technology is necessary in order to acquire high performance specifications. This thesis reports a high performance accelerometer with a new process by making the use of bulk micromachining technology. The new process includes the utilization of Silicon-on-Insulator (SOI) wafer and its buried oxide (BOX) layer. The BOX layer helps to realize interdigitated finger structures, which commonly find place in surface micromachined CMOS-MEMS capacitive accelerometers. The multi-metal layered CMOS-MEMS devices inherently incorporate interdigitated finger structures. Interdigitated finger structures are highly sensitive to acceleration in comparison with comb-finger structures, which generally find usage in bulk-micromachined devices, due to absence of anti-gap. The designed sensors based on this fabrication process is sought to form a fully-differential signal interfaced sensor with incorporation of the advantages of high sensitive interdigitated finger electrodes and high aspect ratio SOI wafer&rsquo / s bulk single crystal silicon device. Under the light of the envisaged process, sensor designs were made, and verified using a computing environment, MATLAB, and a finite element analysis simulator, CoventorWARE. The verified two designs were fabricated, and all the tests, except the centrifuge test, were made at METU-MEMS Research Center. Among the fabricated sensors, the one designed for the high performance achieves a capacitance sensitivity of 178 fF with a rest capacitance of 8.1 pF by employing interdigitated finger electrodes, while its comb-finger implementation can only achieve a capacitance sensitivity of 75 fF with a rest capacitance of 10 pF.
102

Integrierte Hochvolt-Ansteuerelektronik für Mikroaktoren mit elektrostatischem Antrieb

Heinz, Steffen 29 August 2006 (has links) (PDF)
Die vorliegende Arbeit behandelt integrierte Hochvolt-Schaltungen für die Ansteuerung elektrostatisch arbeitender Mikroaktoren und Mikroaktorarrays. Im Besonderen wird auf die Gesichtspunkte der Treiberschaltungen von Torsionsspiegelarrays eingegangen. Es werden verschiedene Verstärkerbetriebsarten und Schaltungsvarianten hinsichtlich der Ansteuerung kleiner kapazitiver Lasten beurteilt. Für die hocheffiziente Signalübertragung zwischen Low-Side und High-Side in geschalteten Hochvolt-Verstärkern wird ein neuer dynamischer Level-Shifter vorgestellt. Anhand eines gebondeten Mikroelektronik-Mikromechanik-Aufbaus für ein Hadamard-Transformations-Spektrometer werden die speziellen Aspekte des Elektronikentwurfs für ein System-in-Package aufgezeigt. Als Entwurfsgrundlage wird ein Überblick über die wesentlichen Isolationstechnologien für integrierte Hochvolt-Schaltungen und über die Bauelementemodellierung in einer SOI-Technologie ausgearbeitet. Außerdem werden die Vor- und Nachteile der wichtigsten Antriebsprinzipien von Mikroaktoren zusammengefasst.
103

Multi-layer silicon photonic devices for on-chip optical interconnects

Zhang, Yang, active 2013 25 February 2014 (has links)
Large on-chip bandwidths required for high performance electronic chips will render optical components essential parts of future on-chip interconnects. Silicon photonics enables highly integrated photonic integrated circuit (PIC) using CMOS compatible process. In order to maximize the bandwidth density and design flexibility of PICs, vertical integration of electronic layers and photonics layers is strongly preferred. Comparing deposited silicon, single crystalline silicon offers low material absorption loss and high carrier mobility, which are ideal for multi-layer silicon PIC. Three different methods to build multi-layer silicon PICs based on single crystalline silicon are demonstrated in this dissertation, including double-bonded silicon-on-insulator (SOI) wafers, transfer printed silicon nanomembranes, and adhesively bonded silicon nanomembranes. 1-to-12 waveguide fanouts using multimode interference (MMI) couplers were designed, fabricated and characterized on both double-bonded SOI and transfer printed silicon nanomembrane, and the results show comparable performance to similar devices fabricated on SOI. However, both of these two methods have their limitations in optical interconnects applications. Large and defect-free silicon nanomembrane fabricated using adhesive bonding is identified as a promising solution to build multi-layer silicon PICs. A double-layer structure constituted of vertically integrated silicon nanomembranes was demonstrated. Subwavelength length based fiber-to-chip grating couplers were used to couple light into this new platform. Three basic building blocks of silicon photonics were designed, fabricated and characterized, including 1) inter-layer grating coupler based on subwavelength nanostructure, which has efficiency of 6.0 dB and 3 dB bandwidth of 41 nm, for light coupling between layers, 2) 1-to-32 H-tree optical distribution, which has excess loss of 2.2 dB, output uniformity of 0.72 dB and 3 dB bandwidth of 880 GHz, 3) waveguide crossing utilizing index-engineered MMI coupler, which has crossing loss of 0.019 dB, cross talk lower than -40 dB and wide transmission spectrum covering C-band and L-band. The demonstrated integration method and silicon photonic devices can be integrated into the CMOS back-end process for clock distribution and global signaling. / text
104

Trade-offs between performance and reliability of sub 100-nm RF-CMOS technologies

Arora, Rajan 11 September 2012 (has links)
The objective of this research is to develop an understanding of the trade-offs between performance and reliability in sub 100-nm silicon-on-insulator (SOI) CMOS technologies. Such trade-offs can be used to demonstrate high performance reliable circuits in scaled technologies. Several CMOS reliability concerns such as hot-carrier stress, ionizing irradiation damage, RF stress, temperature effects, and single-event effects are studied. These reliability mechanisms can cause temporary or permanent damage to the semiconductor device and to the circuits using them. Several improvements are made to the device layout and process to achieve optimum performance. Parasitics are shown to play a dominant role in the performance and reliability of sub 100-nm devices. Various techniques are suggested to reduce these parasitics, such as the use of the following: a) optimum device-width, b) optimum gate-finger to gate-finger spacing, c) optimum source/drain metal contact spacing, and d) floating-body/body-contact. The major contributions from this research are summarized as follows: 1) Role of floating-body effects on the performance and reliability of sub 100-nm CMOS-on-SOI technologies is investigated for the first time [1], [2]. It is demonstrated through experimental data and TCAD simulations that floating-body devices have improved RF performance but degraded reliability compared to body-contacted devices. 2) Floating-body effects in a cascode core is studied. Cascode cores are demonstrated to achieve much larger reliability lifetimes than a single device. A variety of cascode topologies are studied to achieve the trade-o s between performance and reliability for high-power applications [2]. 3) The use of body-contact to modulate the performance of devices and single-poledouble- throw (SPDT) switches is studied. The SPDT switch performance is shown to improve with a negative body-bias. 4) The impact of device width on the RF performance and reliability is studied. Larger width devices are shown to have greater degradation, posing challenging questions for RF design in strained-Si technologies [3]. 5) A novel study showing the e ect of source/drain metal contact spacing and gate-finger to gate-finger spacing on the device RF performance is carried out. Further, the impact of above on the hot-carrier, RF stress, and total-dose irradiation tolerance is studied [3], [4]. 6) Latchup phenomenon in CMOS is shown to be possible at cryogenic temperatures (below 50 K), and its consequences are discussed [5]. 7) A time-dependent device degradation model has been developed in technology computer aided design (TCAD) to model reliability in CMOS and SiGe devices. 8) The total-dose irradiation tolerance and hot-carrier reliability of 32-nm CMOSon- SOI technology is reported for the first time. The impact of HfO2 based gate dielectric on the performance and reliability is studied [6]. 9) The impact of technology scaling from 65-nm to 32-nm on the performance and reliability of CMOS technologies is studied [6]. 10) Cryogenic performance and reliability of 45-nm nFETs is investigated. The RF performance improves significantly at 77 K. The hot-carrier device reliability is shown to improve at low temperatures in short-channel CMOS technologies.
105

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

Bellini, Marco 02 March 2009 (has links)
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).
106

Thermal analysis of A1GaN/GaN HEMT monolithic integration with CMOS on silicon <111> substrates /

Chyurlia, Pietro Natale Alessandro, January 1900 (has links)
Thesis (M.App.Sc.) - Carleton University, 2007. / Includes bibliographical references (p. 73-76). Also available in electronic format on the Internet.
107

High-efficiency switched-mode power amplifier using gallium nitride on silicon hemt technology /

Panesar, Harpreet, January 1900 (has links)
Thesis (M.App.Sc.) - Carleton University, 2007. / Includes bibliographical references (p. 112-118). Also available in electronic format on the Internet.
108

Modelamento do single-Event effiects em circuitos de memória FDSOI / Single event effects modeling in FDSOI memory circuits

Bartra, Walter Enrique Calienes January 2016 (has links)
Este trabalho mostra a comparação dos efeitos das falhas provocadas pelos Single-Event Effects em dispositivos 28nm FDSOI, 28nm FDSOI High-K e 32nm Bulk CMOS e células de memória 6T SRAM feitas com estes dispositivos. Para conseguir isso, foram usadas ferramentas TCAD para simular falhas transientes devido a impacto de íons pesados a nível dispositivo e nível circuito. As simulações neste ambiente tem como vantagem a simulação dos fatos e mecanismos que produz as falhas transientes e seus efeitos nos dispositivos, além de também servir para projetar virtualmente estes dispositivos e caraterizar eles para estas simulações. Neste caso, foram projetados três dispositivos para simulação: um transistor NMOS de 32nm Bulk, um transistor NMOS de 28nm FDSOI e um transistor NMOS de 28nm FDSOI High-K para fazer comparações entre eles. Estes dispositivos foram projetados, caraterizados e testados contra o impacto de íons pesados a níveis dispositivo e circuito. Como resultado obtido, transistor Bulk de 32nm teve, no pior caso, uma carga coletada de 7.57 e 7.19 vezes maior que a carga coletada pelo dispositivo FDSOI de 28nm e FDSOI High-K de 28nm respectivamente atingido pelo mesmo íon pesado de 100MeV-cm2/mg. Com estes dados foi possível modelar o comportamento da carga coletada de ambos dispositivos usando este íon pesado, atingindo os terminais de Fonte e Dreno em distintos lugares e ângulos. Usando a mesma ferramenta e os dados obtidos de carga coletada pelos testes anteriores, foram projetadas células de memória SRAM de 6 transistores. Isso foi para testar elas contra os efeitos do impacto de íons pesados nos transistores NMOS de armazenagem da dados. Neste caso, a Transferência Linear de Energia (LET) do íon necessária para fazer que o dado armazenado na SRAM Bulk mude é 12.8 vezes maior que no caso da SRAM FDSOI e 10 maior no caso da SRAM FDSOI High-K, embora a quantidade de carga coletada necessária para que o dado mude em ambas células seja quase a mesma. Com estes dados foi possível modelar os efeitos dos íons pesados em ambos circuitos, descobrir a Carga Crítica destes e qual é o mínimo LET necessário para que o dado armazenado nestas SRAMs mude. / This work shows a comparison of faults due to Single-Event Effects in 28nm Fully Depleted SOI (FDSOI), 28nm FDSOI High-K and 32nm Bulk CMOS devices, and in 6T SRAM memory cells made with these devices. To provide this, was used TCAD tools to simulate transient faults due to heavy ion impacts on device and circuit levels. The simulations in that environment have the advantage to simulate the facts and mechanisms which produce the transient faults and this effects on the electronic devices, it also allow to simulate the virtual device fabrication and to characterize them. In this case, two devices were created for the simulations: a 32nm Bulk NMOS transistor and a 28nm FDSOI NMOS transistor for compare them. These devices were created, characterized and tested against heavy ion impacts at device and circuit levels. The results show that 32nm Bulk transistor has, in the worst case, a collected charge 7.57 and 7.19 times greater than the 28nm FDSOI and 28nm FDSOI High-K respectively collected charge with the same 100MeV-cm2/mg heavy ion. With these data it was possible to model the behavior of the collected charge in both devices with the same heavy-ion, reach the Source and Drain Terminal in different places and angles. Using the same tools and the obtained collected charge data of previous simulations, it was designed 6 transistors SRAM Memory Cells. That is done to test these circuits against the heavy ion effects on the data-storage NMOS transistor. In this case, the necessary Ion Linear Energy Transfer (LET) to flip the Bulk SRAM is 12.8 greater than the FDSOI SRAM and 10 times greater than the FDSOI High- K SRAM case, although the amount of charge to flip the cells is almost the same in both cases. With these data it was possible to model the heavy-ion effects in both circuits, discover the Critical Charge of them and the minimum LET to flips these SRAMs.
109

Modelamento do single-Event effiects em circuitos de memória FDSOI / Single event effects modeling in FDSOI memory circuits

Bartra, Walter Enrique Calienes January 2016 (has links)
Este trabalho mostra a comparação dos efeitos das falhas provocadas pelos Single-Event Effects em dispositivos 28nm FDSOI, 28nm FDSOI High-K e 32nm Bulk CMOS e células de memória 6T SRAM feitas com estes dispositivos. Para conseguir isso, foram usadas ferramentas TCAD para simular falhas transientes devido a impacto de íons pesados a nível dispositivo e nível circuito. As simulações neste ambiente tem como vantagem a simulação dos fatos e mecanismos que produz as falhas transientes e seus efeitos nos dispositivos, além de também servir para projetar virtualmente estes dispositivos e caraterizar eles para estas simulações. Neste caso, foram projetados três dispositivos para simulação: um transistor NMOS de 32nm Bulk, um transistor NMOS de 28nm FDSOI e um transistor NMOS de 28nm FDSOI High-K para fazer comparações entre eles. Estes dispositivos foram projetados, caraterizados e testados contra o impacto de íons pesados a níveis dispositivo e circuito. Como resultado obtido, transistor Bulk de 32nm teve, no pior caso, uma carga coletada de 7.57 e 7.19 vezes maior que a carga coletada pelo dispositivo FDSOI de 28nm e FDSOI High-K de 28nm respectivamente atingido pelo mesmo íon pesado de 100MeV-cm2/mg. Com estes dados foi possível modelar o comportamento da carga coletada de ambos dispositivos usando este íon pesado, atingindo os terminais de Fonte e Dreno em distintos lugares e ângulos. Usando a mesma ferramenta e os dados obtidos de carga coletada pelos testes anteriores, foram projetadas células de memória SRAM de 6 transistores. Isso foi para testar elas contra os efeitos do impacto de íons pesados nos transistores NMOS de armazenagem da dados. Neste caso, a Transferência Linear de Energia (LET) do íon necessária para fazer que o dado armazenado na SRAM Bulk mude é 12.8 vezes maior que no caso da SRAM FDSOI e 10 maior no caso da SRAM FDSOI High-K, embora a quantidade de carga coletada necessária para que o dado mude em ambas células seja quase a mesma. Com estes dados foi possível modelar os efeitos dos íons pesados em ambos circuitos, descobrir a Carga Crítica destes e qual é o mínimo LET necessário para que o dado armazenado nestas SRAMs mude. / This work shows a comparison of faults due to Single-Event Effects in 28nm Fully Depleted SOI (FDSOI), 28nm FDSOI High-K and 32nm Bulk CMOS devices, and in 6T SRAM memory cells made with these devices. To provide this, was used TCAD tools to simulate transient faults due to heavy ion impacts on device and circuit levels. The simulations in that environment have the advantage to simulate the facts and mechanisms which produce the transient faults and this effects on the electronic devices, it also allow to simulate the virtual device fabrication and to characterize them. In this case, two devices were created for the simulations: a 32nm Bulk NMOS transistor and a 28nm FDSOI NMOS transistor for compare them. These devices were created, characterized and tested against heavy ion impacts at device and circuit levels. The results show that 32nm Bulk transistor has, in the worst case, a collected charge 7.57 and 7.19 times greater than the 28nm FDSOI and 28nm FDSOI High-K respectively collected charge with the same 100MeV-cm2/mg heavy ion. With these data it was possible to model the behavior of the collected charge in both devices with the same heavy-ion, reach the Source and Drain Terminal in different places and angles. Using the same tools and the obtained collected charge data of previous simulations, it was designed 6 transistors SRAM Memory Cells. That is done to test these circuits against the heavy ion effects on the data-storage NMOS transistor. In this case, the necessary Ion Linear Energy Transfer (LET) to flip the Bulk SRAM is 12.8 greater than the FDSOI SRAM and 10 times greater than the FDSOI High- K SRAM case, although the amount of charge to flip the cells is almost the same in both cases. With these data it was possible to model the heavy-ion effects in both circuits, discover the Critical Charge of them and the minimum LET to flips these SRAMs.
110

SOI Based Integrated-Optic Microring Resonators for Biomedical Sensing Applications

Mangal, Nivesh January 2012 (has links) (PDF)
Integrated Silicon Photonics has emerged as a powerful platform in the last two decades amongst high-bandwidth technologies, particularly since the adop- tion of CMOS compatible silicon-on-insulator(SOI) substrates. Microring res- onators are one of the fundamental blocks on a photonic integrated circuit chip o ering versatility in varied applications like sensing, optical bu ering, ltering, loss measurements, lasing, nonlinear e ects, understanding cavity optomechanics etc. This thesis covers the design and modeling of microring resonators for biosensing applications. The two applications considered are : homogeneous biosensing and wrist pulse pressure monitoring. Also, the designs have been used to fabricate ring resonator device using three different techniques. The results obtained through characterization of these devices are presented. Following are the observations made in lieu of this: 1) Design modeling and analysis - The analysis of ring resonator requires the study of both the straight and bent waveguide sections. Both rib and strip waveguide geometries have been considered for constructing the device as a building block by computing their respective eigen modes for both quasi-TE and quasi-TM polarizations. The non-uniform evanescent coupling between the straight and curved waveguide has been estimated using coupled mode theory. This method provided in estimating the quality-factor and free spec- tral range (FSR) of the ring-resonator. A case for optimizing the waveguide gap in the directional coupler section of a ring resonator has been presented for homogeneous biosensing application. On similar lines, a model of applying ring resonator for arterial pulse-pressure measurement has been analyzed. The results have been obtained by employing FD-BPM and FDTD including semi- vectorial eigen mode solutions to evaluate the spectral characteristics of ring resonator. The modeling and analytical results are supported by commercial software tools (RSoft). 2) Fabrication and Characterization - For the fabrication, we employ the design of ring resonator of radius 20 m on SOI substrate with two different waveguide gaps of 350 and 700 nm. Three different process sows have been used for fabricating the same device. The rst technique involved using negative e-beam resist HSQ which after exposure becomes SiO2, acts as a mask for Reactive-Ion Etching (RIE); helping in eliminating an additional step. The second technique involved the use of positive e-beam resist, PMMA for device patterning followed by metal deposition with lift-o . The third tech- nique employed was Focussed Ion-beam (FIB) which is resist-less patterning by bombarding Ga+ ions directly onto the top surface of the wafer with the help of a GDS le. The characterization process involved estimation of loss and observing the be- havior of optical elds in the device around the wavelength of 1550 nm using near-field scanning optical microscopy (NSOM) measurement. The estimation of roughness-induced losses has been made by performing Atomic Force Microscopy (AFM) measurements. In summary, the thesis presents novel design and analysis of SOI based microring resonators for homogeneous biosensing and wrist pulse pressure sensing applications. Also, the fabrication and characterization of 20 m radius ring- resonator with 500 500 nm rib cross-section is presented. Hence, this study brings forth several practical issues concerning application of ring resonators to biosensing applications.

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