Abstract—In this paper, we present the fabrication and test results of an oxide-coated polysilicon disk resonator gyroscope in a wafer-scale encapsulation process. We demonstrate the effects of an oxide coating on the device structure and the key performance parameters of resonant-based sensors, such as the temperature coefficient of frequency and quality factor (Q). Results from the as-fabr…
Abstract—We present a technique for estimation of the model parameters for a single-mode vibration of symmetric micromechanical resonators, including the coefficients of conservative and dissipative nonlinearities. The nonlinearities result in an amplitude-dependent frequency and a nonexponential decay, which are characterized from the ringdown response. An analysis of the amplitude of the ri…
Abstract—This paper investigates in detail a micro scale in-plane gap closing electrostatic energy harvester with strong nonlinearities in squeeze-film damping, electromechanical coupling, and impacts on end-stops. The device shows softening response on increasing the bias voltage and saturation behavior on impact with end-stops at high enough acceleration amplitude. We demonstrate that a lu…
Abstract—This paper presents a wine-glass bulk mode disk resonator based on a novel transverse piezoelectric actuation technique to achieve bulk mode resonance of the single crystalline silicon disk structure. The device is fabricated in a commercial microelectromechnical systems (MEMS) process, and combines reasonable quality factor and superior motional resistance in a low-cost technology.…
Abstract—This paper presents the concept, basic theory, fabrication, and testing results of dual-electrode bimorph piezoelectric micromachined ultrasonic transducers (pMUTs) for both air- and liquid-coupled applications. Both the theoretical analyses and experimental verifications under the proposed differential drive scheme display high drive sensitivity and an electromechanical coupling ene…
Abstract—This paper reports a novel infrared focal plane array (FPA) using SiNx/SiO2/SiNx sandwiched structure as the supporting frames for bimaterial cantilever pixels. The device was fabricated by a bulk silicon process, where a trench backfill technique was employed to form the SiNx/SiO2/SiNx sandwiched frames. By replacing the silicon frame with SiNx/SiO2/SiNx sandwiched frame, the fill f…
Abstract—This paper reports an acceleration sensing method based on two weakly coupled resonators (WCRs) using the phenomenon of mode localization. When acceleration acts on the proof masses, differential electrostatic stiffness perturbations will be applied to the WCRs, leading to mode localization, and thus, mode shape changes. Therefore, acceleration can be sensed by measuring the amplitud…
Abstract—This paper presents the implementation of an automated roll-to-roll fluidic self-assembly system based on the surface tension driven self-assembly with applications in the field of macroelectronics. The reported system incorporates automated agitation, web motion, component dispensing, and recycling. The process enables the assembly and electrical connection of semiconductor dies/chi…
Abstract—This paper demonstrates a new class of AlN-based piezoelectric resonators for operation in the microwave frequency range. These novel devices are identified as cross-sectional-Lamémode resonators (CLMRs) as they rely on the piezoelectric transduction of a Lamé mode, in the cross section of an AlN plate. Such a 2-D mechanical mode of vibration, characterized by motion along both the…
Abstract—This paper presents a novel tri-beam structured dog-bone resonance-mode micro-sensor, with a frequency readout piezoresistive Wheatstone-bridge independently located at the central beam for the detection of liquid-phase bio/chemical analyte. Compared with the conventional dual-beam dog-bone resonator, the tri-beam resonator has advantages in the elimination of signal feed-through an…
Abstract—This paper reports a three degree-offreedom (3DoF) microelectromechanical systems (MEMS) resonant sensing device consisting of three weakly coupled resonators with enhanced sensitivity to stiffness change. If one resonator of the system is perturbed by an external stimulus, mode localization occurs, which can be detected by a change of modal amplitude ratio. The perturbation can be,…
Abstract—In this paper, a smart pill for local drug delivery is presented. The pill is designed to achieve local therapy on gastrointestinal tissue thanks to a novel drug delivery system (DDS). The DDS consists of a miniature electrolytic pump. This microfabricated pump is ideal for medical applications because of its low power consumption, compatibility with small size batteries, integrabili…
Abstract—This paper presents a novel z-axis Lorentz force magnetometer coupled with a low-power readout integrated circuit. The sensor is fabricated using an industrial process, and exploits an Al-on-polysilicon multi-loop architecture that gives a five-fold sensitivity and resolution improvement, useful for off-resonance operation. The integrated readout is based on a differential charge amp…
Abstract—In this paper, the design and fabrication of a new radio frequency (RF) microelectromechanical system (MEMS) switch structure is presented. This RF MEMS switch is developed to get the minimum permanent deformation on the microbridge after 200 °C thermal treatment. The residual stress-based buckling on the MEMS bridge is simulated for 5–40-MPa/μm stress gradient (σ) with 5-MPa/…
Abstract—In this paper, we design, fabricate, and validate a large-stroke 3-degree-of-freedom (DOF) positioning stage with integrated displacement sensors for feedback control in a single-mask microelectromechanical systems (MEMS) fabrication process. Three equal shuttles exactly define the position of the stage in x, y, and Rz. The kinematic relation between the shuttle positions and the sta…
Abstract—This paper reports a highly reliable electrostatic microelectromechanical systems (MEMS) relay for high-power switching applications. The main proposal to elevate reliability is to reduce thermal damage in the contact area. Since a contact resistance is the key parameter determining the amount of Joule-heating and the corresponding thermal damage, we devised a unique spring structur…
Abstract—This paper, the first of two parts, reports the design and fabrication of a fully integrated oven controlled microelectromechanical oscillator (OCMO). This paper begins by describing the limits on oscillator frequency stability imposed by the thermal drift and electronic properties (Q, resistance) of both the resonant tank circuit and feedback electronics required to form an electro…
Copping, Campbell, and Muncer (2014) have recently published an article critical of the psychometric approach to the assessment of life history (LH) strategy. Their purported goal was testing for the convergent validation and examining the psychometric structure of the High-K Strategy Scale (HKSS). As much of the literature on the psychometrics of human LH during the past decade or so has emana…
In light of previous research showing that different types of relationships affect levels of testosterone in men, this study examined whether categorizing relationship types according to relationship length can shed further light on variations in levels of testosterone. Salivary testosterone samples were obtained from a sample of men and details about their relationship status, sociosexual orie…
This analysis of previously collected data examined four fitness-relevant issues for their possible role in marital conflict. These were sex, finances, division of labor, and raising children, selected in light of their pertinence to sex differences in reproductive strategies. Over 2,000 couples in five diverse cultures were studied. Marital conflict was assessed by the Problems with Partner sc…
Abstract—This paper reports a compact Fourier transform spectrometer system with a large-stroke electrothermal microelectromechanical systems (MEMS) mirror and other optical components all integrated on a micromachined silicon optical bench with the footprint of 2 cm × 2 cm. The linear optical path difference (OPD) scan range generated by the MEMS mirror reaches up to 450 μm, and the tiltin…
Abstract—A technique using digital masks without ultraviolet light to rapidly print 3-D biopolymer structures with complex microarchitectures in a microfluidic chip has been demonstrated. In this approach, a customized system is used to project light images on a photoconductive substrate in order to create localized virtual electrodes when an alternating electric field is applied across the f…
Abstract—Electrostatically actuated microshutter arrays consisting of rotational microshutters (shutters that rotate about a torsion bar) were designed and fabricated through the use of models and experiments. Design iterations focused on minimizing the torsional stiffness of the microshutters while maintaining their structural integrity. Mechanical and electromechanical test systems were con…
Abstract—Die attach is the process of mounting a plurality of dice to a printed circuit board (PCB) or substrate. Die attach is critical to the thermal and electrical performance of semiconductor products, significantly affecting the final yield of PCBs. In general, the die attacher records alarm events, change events, and maintenance events in a log. Alarm events occur when dice are not alig…
Abstract—Wet chemical processes in integrated circuit (IC) manufacturing are used in many applications, e.g., post-etch residue removal and pre-deposition surface treatment. While advanced single-wafer wet spin tools are part of the critical toolset for advanced IC fabrication, non-optimized tool hardware and/or process may induce different types of wafer surface charging issues. In this pap…
Abstract—In semiconductor manufacturing, wafer fabrication is followed by chip assembly where individual dies are assembled as a packaged chip. In between, dies are tested in terms of their electrical properties and those which fail to pass the “wafer test” are filtered out. However, some faulty dies pass the test and cause a packaged chip to fail in the final test. The inaccuracy of the …
Abstract—This paper evaluates various optical metrology techniques for in-line control of the niformity of 3-D stacked structures. Key process steps during 3-D integration flow were identified and characterized in order to quantify their specific intra-wafer dispersion signature. The cross correlation between the various intra-wafer process step signatures was then analyzed to verify the data…
Abstract—In the high-tech industries, on-line quality monitoring on each workpiece under processing is required to ensure process stability and improve yield rate. However, conducting workpiece-by-workpiece actual metrology is very expensive and time-consuming. In this case, a novel idea is to use “virtual metrology” (VM) that conjectures workpiece quality based on process data collected…
Abstract—We developed a method to compact the glass sheets of a flat-panel displays that use metal-induced laterally crystallized (MILC) polycrystalline-silicon (poly-Si) thin-film transistors (TFTs), and the effects of thermal stress on the fabricated devices were compared against those of a bare-glass device. The glass substrate was exposed to a temperature of 650 ◦C for 40 h in order to …
Abstract— The results of an ongoing collaborative project between the New Jersey Institute of Technology (NJIT) and SEMATECH on the temperature-dependent emissivity of siliconrelated materials and structures are presented in this study. These results have been acquired using a spectral emissometer. This emissometer consists of a Fourier Transform Infra-Red (FTIR) spectrometer designed specifi…
Abstract—Defects on semiconductor wafers are not uniformly distributed, but tend to cluster. These spatial defect patterns contain useful information about issues during integrated circuit fabrication. Promptly detecting abnormal wafers is an important way to increase yield and product quality. However, research on identifying spatial defect patterns has focused only on flash memory with a s…
Abstract—This paper mainly focuses on establishing the stability conditions of the double exponentially weighted moving average (d-EWMA) controller with metrology delay when the process experiences a general disturbance and analyzing its control performance under some typical types of process disturbance. The necessary and sufficient conditions for stability are established by Routh–Hurwit…
Abstract—This paper studies the challenging problem of scheduling single-arm multi-cluster tools with wafer residency time constraints. They have a linear topology and their bottleneck tool is process-bound. This work aims to find an optimal one-wafer cyclic schedule. With the Petri net model developed in our previous work and the minimal cycle time for a multicluster tool without wafer resi…
Abstract—A cluster tool which is widely used for wafer fabrication processes consists of several processing modules (PMs), a transport robot, loadlocks, and an equipment front-end module (EFEM) in which a wafer cassette is loaded and unloaded. A wafer cassette with 25 identical wafers is transported by an overhead hoist transfer (OHT) between cluster tools and stored in a stocker when the co…
Abstract—The trends of increasing wafer diameter and smaller lot sizes have led to more transient periods in wafer fabrication. For some wafer fabrication processes, such as atomic layer deposition, wafers need to visit some process modules for a number of times, instead of once, thus leading to a so-called revisiting process. Most previous studies on cluster tool scheduling focus on steady s…
This article synthesizes the current research on bullying prevention and intervention in order to provide guidance to schools seeking to select and implement antibullying strategies. Evidence-based best practices that are shared across generally effective antibullying approaches are elucidated, and these strategies are grounded in examples garnered from model antibullying programs as implemente…
Non-avian dinosaurs went extinct 66 million years ago, geologically coincident with the impact of a large bolide (comet or asteroid) during an interval of massive volcanic eruptions and changes in temperature and sea level. There has long been fervent debate about how these events affected dinosaurs. We review a wealth of new data accumulated over the past two decades, provide updated and novel…
Bullying in higher education is an increasingly common phenomenon that negatively affects organizational climate, completed work’s quality and quantity, and students’ educational experiences. The purpose of this phenomenological study was to investigate the lived experiences of women adult educators who were targets of bullying. Six themes emerged from the composite participant experiences …
Abstract—Defect detection and classification in semiconductor wafers has received an increasing attention from both industry and academia alike. Wafer defects are a serious problem that could cause massive losses to the companies’ yield. The defects occur as a result of a lengthy and complex fabrication process involving hundreds of stages, and they can create unique patterns. If these patt…
Abstract—This paper presents challenges encountered in the fabrication of high aspect ratio (AR) via middle, through-silicon vias (TSVs), of 3 μm top entrant critical dimension and 50 μm depth. Higher AR TSV integration is explored due to the lower stress and copper pumping influence of TSVs observed in adjacent CMOS devices. The key process improvements demonstrated in this paper include 3…
Abstract—Particles within plasma etching equipment stick to the wafer and cause defects, resulting in large scale integrated circuit (LSI) yield reduction.We observed the behavior of particles resuspended in a vacuum chamber using a laser light scattering method. Investigating the influences of gases, static electricity, and plasma on particle resuspension, we found out that particles are no…
Abstract—This paper proposes optimization methods of re-entrant hybrid flows with multiple queue time constraints in batch processes of semiconductor manufacturing. A smoothing flow concept and a dispatching rule for the re-entrant flows called “re-entrant flow smoothing” [REFS(X)] and a loading rule for the processes with multiple queue time constraints called “synchronized control of…
Abstract—This paper provides an overview of new approaches for assessing and addressing requirements for carrier logistics in semiconductor manufacturing and discusses solutions for optimizing the efficiency of capital equipment installed in the fab. An exploration of crucial influencing factors (both on the material handling as well as on the equipment side) will be followed by a discussion …
Abstract—Alloy seedlayers for copper back-end of line interconnects have become common at technology groundrules of 45 nm and below, due to reliability requirements. The key requirement of the minority alloy component (e.g., Al or manganese, also referred to as the “dopant”) is that it segregates to the copper (Cu)/dielectric cap layer interface in order to promote adhesion between the C…
Abstract—The problem of modeling and generating an optimal design of a rapid thermal processing (RTP) system for flat panel display glass was addressed. An RTP system using bulb-type tungsten-halogen lamps was considered, and a dynamic model to describe the glass temperature distribution was established. The power dispersion function comprising the model was established in an experimental R…
Abstract In semiconductor manufacturing, the technologies of stacked semiconductor packaging are important miniaturization strategies in which excellent quality is essential for a good reputation. Yield-based index Cpk has been the most popular tool for successful quality improvement activities and quality program implementation in multichip package processes. For in-plant applications, quali…
Abstract In this paper, a cost-effective, easy-install and fast measurement and analysis method to obtain seismic response of semiconductor manufacturing equipments was developed and its validity was discussed. In the developed method, micro-vibration measurement experiments are first carried out to obtain transfer functions and coherence functions from the floor to arbitrary part of equipment…
Abstract Development of touch display driver IC (TDDI) has enabled slimmer smartphone design by virtue of the integration of touch controller and display driver ICs (DDIs) into a single chip. TDDI plays an important role in touch integrated display panels. Compared to conventional DDI, TDDI requires more bonding pads for touch applications, thus increasing the usage of gold. The requirement to…