We present a practical method to evaluate gas permeability for thin polymer films using an encapsulated micro-electro-mechanical-system (MEMS) oscillator. Previously, we have developed a hermetic ...thin-film dome structure for RF-MEMS tunable capacitor, using conventional back-end-of-the-line (BEOL) processes. The dome is made of multiple layers including a polymer film, whose gas permeability is an important factor with respect to productivity and reliability. So far, it had been difficult to evaluate the gas permeability for such small and thin polymer films with sub-millimeter diameter and micron-scale thickness. In this evaluation method, the pressure dependence of air-damping oscillation is used to measure the permeability. As a demonstration, we carried out a permeability measurement of a 0.5-mm-diameter dome sealed with a thin (1 μm) polymer film. The resulting permeability coefficient is found to be 1×10 -16 mol/m/Pa/s, at room temperature.
This paper presents an RF MEMS tunable capacitor that achieves an excellent power-handling property with relatively low actuation voltage. The tunable capacitor consists of two fixed MIM ...(Metal-Insulator-Metal) capacitors and two MEMS capacitor elements, all connected in series. This quadruple series capacitor (QSC) structure enables reduction of the actuation voltage without sacrificing the power-handling capability, since the MIM capacitor reduces the RF voltage amplitude applied to the MEMS capacitors. The measured result demonstrates +36 dBm hot-switching at 85°C with 21V pull-in voltage.
Graphene FETs immobilized with some anions show extremely large modulation of the Fermi level upon light irradiation. The mechanism of the modulation is suggested to be the charge transfer between ...graphene and the anion, which makes photogating effect resulting from capacitive coupling of electrons or holes injection in the anion. We also found that the photo-response could be utilized as a chemical sensor.
This paper presents an RF MEMS tunable capacitor that achieves excellent power-handling property with relatively low actuation voltage. The tunable capacitor consists of two fixed MIM ...(Metal-Insulator-Metal) capacitors and two MEMS capacitor elements, all connected in series. This quadruple series capacitor (QSC) structure enables to reduce the actuation voltage without sacrificing the power-handling capability, since the MIM capacitor reduces the RF voltage amplitude applied to the MEMS capacitors. Measured result demonstrates +36dBm hot-switching at 85C with 21V pull-in voltage.
In this paper, we report the demonstration of odorant capture and detection with a high-sensitivity olfactory system having a membrane-type odorant capture module. We carried out the odorant capture ...experiment with limonene and skatole gases as representative odorants, and the captured concentration was 7.6 nM and 0.2 µM, respectively. Furthermore, we have demonstrated 10 nM sensitivity by the graphene FET biosensor, which implies that our olfactory sensing system can realize from gas capture to sensing.
In this paper, we report a thin-film encapsulation technology for wafer-level microelectromechanical systems (MEMS) variable capacitor package. The electrical characteristics of MEMS are adversely ...affected by moisture. In order to prevent moisture from permeating into a package, the top surface was protected with a plasma-enhanced chemical vapor deposition (PE-CVD) SiN layer. The developed packages become a hybrid thin-film hermetic encapsulation consisting of an internal shell using PE-CVD SiO, a seal layer coating with resin, and an external protective layer formed by PE-CVD SiN. The process is fully compatible with standard low-cost back-end-of-the-line (BEOL) technologies for LSIs as a wafer-level package (WLP). This hybrid structure was very effective for protecting the MEMS device from external moisture. Moreover, the electrode surface area has to be wide, because a wide range of capacities is necessary in MEMS variable capacitors. We have developed a large (1480 times 1080 mum) hermetic thin-film encapsulation as WLP.
We propose an IBA scheme based on a pull-out detection, which is suitable for implementing in a circuit. The scheme is implemented in a driver IC that is part of a module with an RF MEMS variable ...capacitor. No failures are observed over 10 8 cycles at 85degC, which is an accelerated charging condition.
We propose a novel Si photonics module that overcomes the issues of conventional Si photonics modules such as package structure and electrical connection. The module incorporates an optical fiber ...socket fabricated by blind via socket (BVS) technology, which implements backside optical I/O in a photonic IC (PIC) by forming blind via holes on the backside. High-speed high-density electrical connection to both the PIC and an electrical IC (EIC) is also obtained in the module by fan-out wafer level packaging (FOWLP) technology. These technologies achieve a surface-mountable substrate-less fan-out optical module. It realizes a practicable integrated module of optoelectronic devices excellent in terms of electrical characteristics such as signal integrity (SI) and power integrity (PI), heat characteristics, and miniaturization. This paper presents a BVS module that enables optical coupling between a III-V/Si photodiode (PD) fabricated on a Si substrate and a multi-mode optical fiber by passive alignment of only insertion of the fiber into a blind via hole on the backside. High-speed optical signal transmission is also demonstrated with a fan-out optical module in which a BVS and an EIC are integrated by FOWLP and a vertical-cavity surface-emitting laser (VCSEL) or PD is mounted on the BVS.
We propose a new Cu/SiO hybrid bonding process using ultrathin Mn film at the bonding interface. In this process, bonding stability is improved because the bonding interface consists of only Mn. In ...addition, Mn on SiO forms a MnSiO, which is known as a diffusion barrier for Cu during thermal processing, resulting in improved reliability of interconnects in areas of misalignment. To demonstrate the feasibility of this process, we evaluated the bonding strength of Mn/Mn interface and electrical properties of ultrathin Mn film on SiO layer. Good bonding strength was obtained at heating temperatures of 350°C or more. Moreover, it was confirmed that the resistivity of ultrathin Mn film on SiO layer was increased by heat treatment.
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