A extrêmement hautes fréquences, les applications électroniques vont être confrontées à des challenges liés à la réduction des dimensions et la compacité des systèmes. Les limites physiques des matériaux conventionnels étant atteintes, de nouvelles alternatives sont nécessaires dans le domaine du nano-packaging. De nouveaux matériaux ont été étudiés pour remplacer les matériaux conventionnels. Parmi eux, le nanotube de carbone démontre une excellente conductivité électrique et thermique ainsi qu’une résistance physique extraordinaire. Il est donc un candidat de choix pour des applications comme les interconnexions, l’évacuation de chaleur, le blindage électromagnétique ou encore le renforcement structurel. Autant de points capitaux pour le nano-packaging moderne. Dans ce manuscrit, les nanotubes de carbone vont être étudiés en profondeur pour réaffirmer leurs propriétés électroniques et thermiques hors du commun. Nous nous concentrerons ensuite sur l’étude de deux types d’interconnexions à base de nanotubes de carbone : des interconnexions à base de plot en nanotubes de carbone utilisant la technologie Flip-Chip et des interconnexions sans-fil à base de monopole composé de nanotubes de carbone. Enfin, nous étudierons la possibilité de créer des composants passifs Radio-Fréquence à l’aide de structures en nanotubes de carbone. De nouvelles méthodes de fabrication des structures en CNT ont été utilisées au cours de ces travaux de thèse afin d’obtenir une compatibilité avec les technologies CMOS. / At extremely high frequency, electronic applications will have to challenge problems born from the size reduction and compactification of the systems. Physical limits of conventional materials will be reached and so new alternatives are necessary in the nano-packaging field. New materials have been studied to replace conventional materials. Among them, carbon nanotubes have shown extremely high electrical and thermal conductivity as well as extraordinary physical resistance. And so carbon nanotubes are a good candidate for applications such as interconnects, thermal management, electromagnetic shielding or structural reinforcement. All of those applications are capital for modern nano-packaging. In this manuscript, carbon nanotubes will be studied in depths to demonstrate again their incredible electronic and thermal properties. We will then focus on the study of two types of carbon nanotubes based interconnects: carbon nanotubes bumps based interconnects for Flip-Chip applications and wireless interconnects based on carbon nanotubes monopole antenna. Finally, we will study the possibility of creating passive RF components using carbon nanotubes structures. New ways of fabricating the carbon nanotubes structure were used in order to get a fabrication process of the prototype completely compatible with CMOS technologies.

Several fabrication techniques for surface micromachined 3-D structures have been developed for RF components. The fabrication techniques all have in common the use of epoxy patterning and subsequent metallization. Techniques and structures such as embedded conductors, epoxy-core conductors, a reverse-side exposure technique, a multi-exposure scheme, and inclined patterning are presented. The epoxy-core conductor technique makes it easy to fabricate high-aspect-ratio (10-20:1), tall (~1mm) RF subelements as well as potentially very complex structures by taking advantage of advanced epoxy processes. To demonstrate feasibility and usefulness of the developed fabrication techniques for RF applications, two test vehicles are employed. One is a solenoid type RF inductor, and the other is a millimeter wave radiating structure such as a W-band quarter-wavelength monopole antenna. The embedded inductor approach provides mechanical robustness and package compatibility as well as good electrical performance. An inductor with a peak Q-factor of 21 and an inductance of 2.6nH at 4.5GHz has been fabricated on a silicon substrate. In addition, successful integration with a CMOS power amplifier has been demonstrated. A high-aspect-ratio inductor fabricated using epoxy core conductors shows a maximum Q-factor of 84 and an inductance of 1.17nH at 2.6GHz on a glass substrate with a height of 900um and a single turn. Successful W-band monopole antenna fabrication is demonstrated. A monopole with a height of 800um shows its radiating resonance at 85GHz with a return loss of 16dB. In addition to the epoxy-based devices, an advanced tunable ferroelectric device architecture is introduced. This architecture enables a low-loss conductor device; a reduced intermodulation distortion (IMD) device; and a compact tunable LC module. A single-finger capacitor having a low-loss conductor with an electrode gap of 1.2um and an electrode thickness of 2.2um has been fabricated using a reverse-side exposure technique, showing a tunability of 33% at 10V. It shows an improved Q-factor of 21.5. Reduced IMD capacitors consist of wide RF gaps and narrowly spaced high resistivity electrodes with a gap of 2um and a width of 2um within the wide gap. A 14um gap and a 20um gap capacitor show improved IMD performance compared to a 4um gap capacitor by 6dB and 15dB, respectively, while the tunability is approximately 21% at 30V for all three devices due to the narrowly spaced multi-pair high resistivity DC electrodes within the gap. Finally, a compact tunable LC module is implemented by forming the narrow gap capacitor in an inductor shape. The resonance frequency of this device is variable as a function of DC bias and a frequency tunability of 1.1%/V is achieved. The RF components developed in this thesis illustrate the usefulness of the application of micromachining technology to this application area, especially as frequencies of operation of RF systems continue to increase (and therefore wavelengths continue to shrink).

A system packaging level approach on liquid crystal polymer (LCP) was proposed for low cost, lightweight, and compact wireless communication systems. Via technology was explored for V-band W-band transitions and an active cooling system that are essential for compact multilayer integration. RF MEMS switches were fabricated and integrated at the component level to enable multi-functional devices with optimal performance. A pattern reconfigurable antenna for MIMO applications and 3D phase shifters for phased array antennas that use RF MEMS switches were presented. In addition, a lightweight expandable array was designed and measured with up to 256 elements on multilayer LCP integrated at the system level. Furthermore, a 60 GHz multilayer transceiver front end device with simultaneous transmit and receive was designed and measured for low cost 60 GHz applications. The wide variety of multilayer LCP applications integrated at the system level shows a promising future for the next generation low cost lightweight wireless communication systems.

For ultra-high speed communication systems at high center frequencies above 100 GHz, we propose a disruptive change in system architecture to address major issues regarding amplifier chains with a large number of amplifier stages. They cause a high noise figure and high power consumption when operating close to the frequency limits of the underlying semiconductor technologies. Instead of scaling a classic homodyne transceiver system, we employ repeated amplification in single-stage amplifiers through positive feedback as well as synthesizer-free self-mixing demodulation at the receiver to simplify the system architecture notably. Since the amplitude and phase information for the emerging oscillation is defined by the input signal and the oscillator is only turned on for a very short time, it can be left unstabilized and thus come without a PLL. As soon as gain is no longer the most prominent issue, relaxed requirements for all the other major components allow reconsidering their implementation concepts to achieve further improvements compared to classic systems. This paper provides the first comprehensive overview of all major design aspects that need to be addressed upon realizing a SPARS-based transceiver. At system level, we show how to achieve high data rates and a noise performance comparable to classic systems, backed by scaled demonstrator experiments. Regarding the transmitter, design considerations for efficient quadrature modulation are discussed. For the frontend components that replace PA and LNA amplifier chains, implementation techniques for regenerative sampling circuits based on super-regenerative oscillators are presented. Finally, an analog-to-digital converter with outstanding performance and complete interfaces both to the analog baseband as well as to the digital side completes the set of building blocks for efficient ultra-high speed communication.