Bio: A Agarwal is an academic researcher from Singapore Science Park. The author has contributed to research in topic(s): Deep reactive-ion etching & Microelectromechanical systems. The author has an hindex of 2, co-authored 2 publication(s) receiving 64 citation(s).
Abstract: In this paper, a single-mask substrate transfer process for the fabrication of high-aspect-ratio (HAR) suspended structures is presented. The HAR silicon structures are fabricated using a deep reactive ion etching (DRIE) technique and then transferred to a glass wafer using silicon/thin film/glass anodic bonding and silicon thinning techniques. The HAR structures are released using self-aligned wet etching of the glass. Two key processes are discussed. One is the silicon/thin film/glass anodic bonding, with special emphasis on the effect of the bonding material on the bonding shear strength. The other is the silicon backside thinning via aqueous solution of potassium hydroxide (KOH). A lateral RF MEMS switch has been fabricated and demonstrates low loss up to 25 GHz. This substrate transfer process has the advantages of high-aspect ratio, low loss and high flexibility.
Abstract: Two novel lateral metal-contact radio-frequency microelectromechanical system (RF MEMS) switches are reported. These switches are implemented with quasi-finite ground coplanar waveguide (FGCPW) configuration and actuated by applying electrostatic force on a high-aspect-ratio cantilever beam. It is demonstrated that the insertion loss of the switch is less than 0.2 dB up to 15 GHz and the isolation is higher than 20 dB up to 25 GHz. An RF model of the switches is used to analyse the effects of the switch design parameters and RF performance. The optimization of the switch mechanical design is discussed where the threshold voltage can be lower than 25 V. The lateral switches are fabricated by deep reactive ion etching (DRIE) process on a silicon-on-insulator (SOI) wafer with shadow mask technology.
Abstract: In this paper, we report a novel laterally actuated Radio Frequency (RF) Microelectromechanical Systems (MEMS) switch, which is based on a combination of electrothermal actuation and electrostatic latching hold. The switch takes the advantages of both actuation mechanisms: large actuation force, low actuation voltage, and high reliability of the thermal actuation for initial movement; and low power consumption of the electrostatic actuation for holding the switch in position in ON state. The switch with an initial switch gap of 7 µm has an electrothermal actuation voltage of 7 V and an electrostatic holding voltage of 21 V. The switch achieves superior RF performances: the measured insertion loss is −0.73 dB at 6 GHz, whereas the isolation is −46 dB at 6 GHz. In addition, the switch shows high reliability and power handling capability: the switch can operate up to 10 million cycles without failure with 1 W power applied to its signal line.
Abstract: In this work we propose a design based on a nanoelectromechanical relay acting as a logic gate inverter. The proposed inverter is made of a double cantilever nanobeam actuated by a fixed central electrode carrying the input signals. The static and dynamic behaviors of the ohmic nanoinverter gate are investigated using an electromechanical mathematical model that fully incorporates nonlinear form of the electrostatic force and the ohmic contact of the nanobeams’ tip with the fixed output electrode. The derived electromechanical model is used for electrical and energy analysis. Simulations are used to confirm the functionality of the inverter. The analysis of the switching energy showed very low power consumption compared to classical CMOS inverters. It is shown that the proposed inverter dissipates only 0.45 fJ to code a “1” logic-state and 0.023 fJ to code a “0” logic-state.
Muhammad Mubasher Saleem and Hamid Nawaz1•Institutions (1)
Abstract: The main challenge in the commercialization of the RF-MEMS switches is their reliability, related to both the electrical and mechanical domains. The development of test standards and understanding the underlying physics of different failure modes has always been of major concern for the RF-MEMS designers. This paper reviews the different failure modes in the RF-MEMS switches like stiction, residual stress, cyclic fatigue, creep, wear and packaging in detail. The origin of these failure modes, their characterization procedure and respective solutions presented in the literature are presented to get a better understanding of the state of the art work done in the field RF-MEMS reliability for nearly past two decades.
•23 Sep 2016
Abstract: In this thesis, MEMS switches actuated using electrostatic actuation is explored. MEMS switches that are lateral switches and clamped-clamped switches are designed, fabricated, and tested in this thesis. This thesis extensively explains the process by which the MEMS Switches were designed and fabricated. In addition, it explains the changes in the switches when issues called for a modification to devices. Contact resistances were extensively studied, in this thesis. There has been a trade-off between the reliability of switches and their contact resistances. Many actions were taken to mitigate this trade-off and to allow both reliable devices with low contact resistances. The efforts to do so ranged from thermal oxidation to reduce the scalloping on the sidewalls, to modifying the dry etching recipe, to modifying the sputtering recipe, to electroplating, and many more. However, reliability of the MEMS Lateral switches was accomplished independent to the contact resistances. In addition, low contact resistances were accomplished independent to reliability. A novel approach to designing clamped-clamped MEMS switches is also showcased in this thesis. These devices experienced unique challenges compared to those faced with lateral switches. Both lateral and clamped-clamped switches are discussed in-depth in this thesis.
Abstract: This letter presents novel high power and reliable radio frequency (RF) microelectromechanical systems switches with single-pole single-throw (SPST) and single-pole triple-throw (SP3T) configurations. An in-plane movable structure with a single layer is made using a simple standard silicon-on-insulator process, which greatly reduces the micro-fabrication complexity and cost compared with the previously reported multi-contact switches with out-of-plane movable structures. The SPST switch achieves a uniform current distribution through each contact, thereby increasing the power handling capability of the switch. The SP3T switch is a derivative of the SPST switch with separate individual actuations. The experimental results demonstrate that the fabricated switches have superior RF performances: insertion losses are −0.9 and −1.3 dB at 6 GHz for SPST and SP3T switches, respectively, whereas isolations are better than −29 and −37 dB from dc to 6 GHz for SPST and SP3T switches, respectively. In hot-switching conditions, the SPST switch can handle RF power up to 2 W for 10 million cycles, whereas the SP3T switch is capable of handling an RF power of 1 W for 7 million cycles before failure occurs.
Author's H-index: 2