With the advancement of silicon electronics under threat from physical limits to dimensional scaling, the International Technology Roadmap for Semiconductors (ITRS) released a white paper in 2008, detailing the ways in which the semiconductor industry can keep itself continually growing in the twenty-first century. Two distinct paths were proposed: More-Moore and More-than-Moore. While More-Moore approach focuses on the continued use of state-of-the-art, complementary metal oxide semiconductor (CMOS) technology for next generation electronics, More-than-Moore approach calls for a disruptive change in the system architecture and integration strategies. In this doctoral thesis, we investigate both the approaches to obtain performance improvement in the state-of-the-art, CMOS electronics. We present a novel channel material, SiSn, for fabrication of CMOS circuits. This investigation is in line with the More-Moore approach because we are relying on the established CMOS industry infrastructure to obtain an incremental change in the integrated circuit (IC) performance by replacing silicon channel with SiSn. We report a simple, low-cost and CMOS compatible process for obtaining single crystal SiSn wafers. Tin (Sn) is deposited on silicon wafers in the form of a metallic thin film and annealed to facilitate diffusion into the silicon lattice. This diffusion provides for sufficient SiSn layer at the top surface for fabrication of CMOS devices. We report a lowering of band gap and enhanced mobility for SiSn channel MOSFETs compared to silicon control devices. We also present a process for fabrication of vertically integrated flexible silicon to form 3D integrated circuits. This disruptive change in the state-of-the-art, in line with the More-than-Moore approach, promises to increase the performance per area of a silicon chip. We report a process for stacking and bonding these pieces with polymeric bonding and interconnecting them using copper through silicon vias (TSVs). We report a process for fabricating through polymer vias (TPVs) facilitating the fabrication of sensor arrays and control electronics on the opposite sides of the same flexible polymer. Finally, we present a process to fabricate stretchable metallic thin films with up to 800% stretchability, and report two distinct applications for these devices which cannot be done using current techniques.

Three-dimensional (3D) integration of micro- and nano-electromechanical systems (MEMS/NEMS) with integrated circuits (ICs) is an emerging technology that offers great advantages over conventional state-of-the-art microelectronics. MEMS and NEMS are most commonly employed as sensor and actuator components that enable a vast array of functionalities typically not attainable by conventional ICs. 3D integration of NEMS and ICs also contributes to more compact device footprints, improves device performance, and lowers the power consumption. Therefore, 3D integration of NEMS and ICs has been proposed as a promising solution to the end of Moore’s law, i.e. the slowing advancement of complementary metal-oxide-semiconductor (CMOS) technology.In this Ph.D. thesis, I propose a comprehensive fabrication methodology for heterogeneous 3D integration of NEM devices directly on top of CMOS circuits. In heterogeneous integration, the NEMS and CMOS components are fully or partially fabricated on separate substrates and subsequently merged into one. This enables process flexibility for the NEMS components while maintaining full compatibility with standard CMOS fabrication. The first part of this thesis presents an adhesive wafer bonding method using ultra-thin intermediate bonding layers which is utilized for merging the NEMS components with the CMOS substrate. In the second part, a novel NEM switch concept is introduced and the performance of CMOS-integrated NEM switch circuits for logic and computation applications is discussed. The third part examines two different packaging approaches for integrated MEMS and NEMS devices with either hermetic vacuum cavities or low-cost glass lids for optical applications. Finally, a novel fabrication approach for through silicon vias (TSVs) by magnetic assembly is presented, which is used to establish an electrical connection from the packaged devices to the outside world. / Tredimensionell (3D) integration av mikro- och nano-elektromekaniska system (MEMS/NEMS) med integrerade kretsar (ICs) är en ny teknik som erbjuder stora fördelar jämfört med konventionell mikroelektronik. MEMS och NEMS används oftast som sensorer och aktuatorer då de möjliggör många funktioner som inte kan uppnås med vanliga ICs.3D-integration av NEMS och ICs bidrar även till mindre dimensioner, ökade prestanda och mindre energiförbrukning av elektriska komponenter. Den nuvarande tekniken för complementary metal-oxide-semicondictor (CMOS) närmar sig de fundamentala gränserna vilket drastiskt begränsar utvecklingsmöjligheten för mikroelektronik och medför slutet på Moores lag. Därför har 3D-integration identifierats som en lovande teknik för att kunna driva vidare utvecklingen för framtidens elektriska komponenter.I denna avhandling framläggs en omfattande fabrikationsmetodik för heterogen 3D-integration av NEMS ovanpå CMOS-kretsar. Heterogen integration betyder att både NEMS- och CMOS-komponenter byggs på separata substrat för att sedan förenas på ett enda substrat. Denna teknik tillåter full processfrihet för tillverkning av NEMS-komponenter och garanterar kompatibilitet med standardiserade CMOS-fabrikationsprocesser.I den första delen av avhandlingen beskrivs en metod för att sammanfoga två halvledarskivor med en extremt tunn adhesiv polymer. Denna metod demonstreras för 3D-integration av NEMS- och CMOS-komponenter. Den andra delen introducerar ett nytt koncept för NEM-switchar och dess användning i NEM-switch-baserade mikrodatorchip. Den tredje delen presenterar två olika inkapslingsmetoder för MEMS och NEMS. Den ena metoden fokuserar på hermetisk vakuuminkapsling medan den andra metoden beskriver en lågkostnadsstrategi för inkapsling av optiska komponenter. Slutligen i den fjärde delen presenteras en ny fabrikationsteknik för så kallade ”through silicon vias” (TSVs) baserad på magnetisk självmontering av nickeltråd på mikrometerskala. / <p>20170519</p>