160 MILLI-OHM ELECTRICAL RESISTANCE THRU-WAFER INTERCONNECTS WITH 10:1 ASPECT RATIO

2014 ◽  
Vol 2014 (1) ◽  
pp. 000505-000510 ◽  
Author(s):  
A. Efimovskaya ◽  
A.M. Shkel

We present a novel approach for high-aspect ratio low resistance Thru-Wafer Interconnects for Double-Sided (TWIDS) fabrication of MicroElectroMechanical Systems (MEMS). The interconnects are formed by etching blind via holes in the handle substrate of an SOI (Silicon on Insulator) wafer, followed by filling the holes with copper, using sonic-assisted seedless copper electroplating process. This technique does not require additional conductive layer deposition, but utilizes a highly doped silicon device layer as a seed. The donut-shape gaps are etched around the copper filled vias to provide interconnects insulation. We introduced the fabrication process and characterized the performance of interconnects. Experimental analysis of an array of 22 interconnects demonstrated that the resistance values as low as 160 milli-Ohm can be achieved. Parasitic capacitance of interconnects is analytically calculated and the distortion of the MEMS resonator transduction spectrum is predicted using an equivalent circuit model. Signal amplitude and phase distortion due to the parasitic capacitance are estimated to be 1.15 dB and 5.96 deg, respectively, for the optimum 60 um diameter via with 35 um insulating gap. The method presented is compatible with an in-house folded MEMS fabrication process and may enable 3D folded TIMU (Timing Inertial Measurement Unit) structures with thru-wafer interconnects.

Micromachines ◽  
2021 ◽  
Vol 12 (3) ◽  
pp. 310
Author(s):  
Muhammad Mubasher Saleem ◽  
Shayaan Saghir ◽  
Syed Ali Raza Bukhari ◽  
Amir Hamza ◽  
Rana Iqtidar Shakoor ◽  
...  

This paper presents a new design of microelectromechanical systems (MEMS) based low-g accelerometer utilizing mode-localization effect in the three degree-of-freedom (3-DoF) weakly coupled MEMS resonators. Two sets of the 3-DoF mechanically coupled resonators are used on either side of the single proof mass and difference in the amplitude ratio of two resonator sets is considered as an output metric for the input acceleration measurement. The proof mass is electrostatically coupled to the perturbation resonators and for the sensitivity and input dynamic range tuning of MEMS accelerometer, electrostatic electrodes are used with each resonator in two sets of 3-DoF coupled resonators. The MEMS accelerometer is designed considering the foundry process constraints of silicon-on-insulator multi-user MEMS processes (SOIMUMPs). The performance of the MEMS accelerometer is analyzed through finite-element-method (FEM) based simulations. The sensitivity of the MEMS accelerometer in terms of amplitude ratio difference is obtained as 10.61/g for an input acceleration range of ±2 g with thermomechanical noise based resolution of 0.22 and nonlinearity less than 0.5%.


2017 ◽  
Vol 2017 ◽  
pp. 1-9 ◽  
Author(s):  
Huisheng Liu ◽  
Zengcai Wang ◽  
Susu Fang ◽  
Chao Li

A constrained low-cost SINS/OD filter aided with magnetometer is proposed in this paper. The filter is designed to provide a land vehicle navigation solution by fusing the measurements of the microelectromechanical systems based inertial measurement unit (MEMS IMU), the magnetometer (MAG), and the velocity measurement from odometer (OD). First, accelerometer and magnetometer integrated algorithm is studied to stabilize the attitude angle. Next, a SINS/OD/MAG integrated navigation system is designed and simulated, using an adaptive Kalman filter (AKF). It is shown that the accuracy of the integrated navigation system will be implemented to some extent. The field-test shows that the azimuth misalignment angle will diminish to less than 1°. Finally, an outliers detection algorithm is studied to estimate the velocity measurement bias of the odometer. The experimental results show the enhancement in restraining observation outliers that improves the precision of the integrated navigation system.


2007 ◽  
Vol 51 (10) ◽  
pp. 1391-1397 ◽  
Author(s):  
Leo Petrossian ◽  
Seth J. Wilk ◽  
Punarvasu Joshi ◽  
Sahar Hihath ◽  
Jonathan D. Posner ◽  
...  

1999 ◽  
Author(s):  
Xiaobin Li ◽  
Siddharth Kiyawat ◽  
Hector J. De Los Santos ◽  
Chang-Jin “CJ” Kim

Abstract Narrow beamwidth is highly desirable for many micromechanical elements moving parallel to the substrate. A good example is the electrostatically driven flexure structure, whose driving voltage is determined by the width of the beam. This paper presents the process flow and the result of a high-aspect-ratio electroplating process using photoresist (PR) molds. Following a systematic optimization method, PR molds with aspect ratios up to 4.0 were fabricated with a beamwidth of only 2.1μm. Higher aspect ratios, up to 6.8, were achieved using PR double coating technique, with a beamwidth of 2.6μm. Using a Cr/Cu seed layer, nickel electroplating was successfully carried out to translate the PR molds into nickel micro-structures. We observed bend-down of the fully released nickel cantilevers that are over 8μm thick. Further investigation suggested a combined effect of residual stress gradient in the electroplated nickel layer and in-use stiction of the cantilever beams.


2010 ◽  
Vol 2010 (1) ◽  
pp. 000947-000953
Author(s):  
Bernd Scholz ◽  
WeiYang Lim ◽  
Ferdous Sarwar ◽  
Syed Sajid Ahmad ◽  
Aaron Reinholz

Fabrication of tall features using selective electrodeposition is well known process and has several applications in microelectronics packaging. The use of conventional exposure and development processes is limited by the aspect ratio and sizes of the features obtained. This paper describes a novel approach to fabricated tall structures featured in thick photoresist . Tin and copper tall structures were made by selective electrodeposition. Also presented are results from experiments performed to fabricate tall tin and copper pillars with nearly vertical walls on bare dices to form interconnect.


Micromachines ◽  
2020 ◽  
Vol 11 (12) ◽  
pp. 1071
Author(s):  
Bo Jiang ◽  
Yan Su ◽  
Guowen Liu ◽  
Lemin Zhang ◽  
Fumin Liu

Disc gyroscope manufactured through microelectromechanical systems (MEMS) fabrication processes becomes one of the most critical solutions for achieving high performance. Some reported novel disc constructions acquire good performance in bias instability, scale factor nonlinearity, etc. However, antivibration characteristics are also important for the devices, especially in engineering applications. For multi-ring structures with central anchors, the out-of-plane motions are in the first few modes, easily excited within the vibration environment. The paper presents a multi-ring gyro with good dynamic characteristics, operating at the first resonant mode. The design helps obtain better static performance and antivibration characteristics with anchor points outside of the multi-ring resonator. According to harmonic experiments, the nearest interference mode is located at 30,311 Hz, whose frequency difference is 72.8% far away from working modes. The structures were fabricated with silicon on insulator (SOI) processes and wafer-level vacuum packaging, where the asymmetry is 780 ppm as the frequency splits. The gyro also obtains a high Q-factor. The measured value at 0.15 Pa was 162 k, which makes the structure have sizeable mechanical sensitivity and low noise.


Sensors ◽  
2019 ◽  
Vol 19 (7) ◽  
pp. 1618 ◽  
Author(s):  
Mohamed Moussa ◽  
Adel Moussa ◽  
Naser El-Sheimy

Recently, land vehicle navigation, and especially by the use of low-cost sensors, has been the object of a huge level of research interest. Consumer Portable Devices (CPDs) such as tablets and smartphones are being widely used by many consumers all over the world. CPDs contain sensors (accelerometers, gyroscopes, magnetometer, etc.) that can be used for many land vehicle applications such as navigation. This paper presents a novel approach for estimating steering wheel angles using CPD accelerometers by attaching CPDs to the steering wheel. The land vehicle change of heading is then computed from the estimated steering wheel angle. The calculated change of heading is used to update the navigation filter to aid the onboard Inertial Measurement Unit (IMU) through the use of an Extended Kalman Filter (EKF) in GNSS-denied environments. Four main factors that may affect the steering wheel angle accuracy are considered and modeled during steering angle estimations: static onboard IMU leveling, inclination angle of the steering wheel, vehicle acceleration, and vehicle inclination. In addition, these factors are assessed for their effects on the final result. Therefore, three methods are proposed for steering angle estimation: non-compensated, partially-compensated, and fully-compensated methods. A road experimental test was carried out using a Pixhawk (PX4) navigation system, iPad Air, and the OBD-II interface. The average Root Mean Square Error (RMSE) of the change of heading estimated by the proposed method was 0.033 rad/s. A navigation solution was estimated while changes of heading and forward velocity updates were used to aid the IMU during different GNSS signal outages. The estimated navigation solution is enhanced when applying the proposed updates to the navigation filter by 91% and 97% for 60 s and 120 s of GNSS signal outage, respectively, compared to the IMU standalone solution.


ChemInform ◽  
2010 ◽  
Vol 24 (42) ◽  
pp. no-no
Author(s):  
H. GASSEL ◽  
J. PETER-WEIDEMANN ◽  
H. VOGT

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