High-performance Microsystems Research Articles

Sub-mK, On-package Temperature Control for High-Performance Microsystem Applications

Sub-mK, On-package Temperature Control for High-Performance Microsystem Applications

(Invited) Heterogeneous Integration of Silicon CMOS Electronics and Compound Semiconductor Electronics for Miniature RF Photonic Transceivers

We are exploring heterogeneous integration (HI) for realizing transceivers that enable short-range and long-range RF photonic interconnect using wavelength-division multiplexing to aggregate RF signals, provide galvanic isolation, and reduce crosstalk and interference. The intimate integration of these functions will allow for higher signal density in congested volumes as well as reduced size weight and power (SWaP).HI of silicon Complementary Metal-Oxide-Semiconductor (CMOS) electronics with compound semiconductor photonics enables high-performance microsystems that combine complex electronic functions with optoelectronic capabilities enabled by rich bandgap engineering opportunities. CMOS is an ideal technology for controlling and interfacing with optoelectronic circuits because of its maturity, accessibility through multiple foundries, and capability for a broad range of mixed-signal and RF functions. However, accessible state-of-the-art CMOS offerings do not include integrated photonic capability, and post-process monolithic integration of photonics is cost-prohibitive for all but the highest volume applications. For photonics, InP-based compound semiconductor technologies offer higher speeds than silicon photonic technologies plus the capability to exploit bandgap engineering to realize the monolithic integration of many functions including lasers, modulators, detectors, couplers, and filters. Unfortunately, compound semiconductor electronics offer poorer integration density and digital logic capabilities compared to CMOS, and monolithic integration of electronic and photonic functions in compound semiconductor technology is very complicated and has only been demonstrated in limited research environments. The differences in materials and processes between CMOS electronics and InP optoelectronics necessitates separate fabrication of the two technologies, followed by HI to achieve a microsystem that takes advantages of the capabilities of these two technologies.In this work, we are comparing and evaluating approaches for integrating 180 nm CMOS RF interface circuits with planar InP photonic integrated circuits and surface-normal GaAs-based optoelectronics. To avoid the critical sub-micron alignment tolerances of optical interfaces, optical signals are constrained to the photonic chip and the interface between the two technologies is limited to electrical signals. Prototype RF electrical-optical transmitters and optical-electrical receivers are being fabricated using both wire-bond and flip-chip integration approaches, and the performance and SWaP benefits provided by HI are being evaluated.In this HI application, the dissimilar materials and small CMOS die present challenges beyond that of either wafer-to-wafer bonding or standard chip-scale solder integration. To address a capability gap for high-density integration of CMOS die with Al pads obtained through multi-project-wafer runs, we are developing methods for adding appropriate under-bump-metallization and process bumps to the Al pads on single die. Flip-chip integration approaches being explored include solder ball scaling down to 75 µm pitch, as well as Cu pillars and Au microbumps with targeted pitches as low as 25 microns.HI offers electrically short interconnects that do not require controlled impedance transmission lines and resistive load termination for high-speed data transfer. Controlled impedance routing with load termination is generally used for high-speed chip-to-chip interconnect because the pads and packaging add parasitic impedance, and the routing length is both uncontrolled by the chip designer and significant relative to an electrical wavelength. Using HI to control and minimize the inter-chip interface allows for electrically short interconnect with a significant power reduction for a given optical driver requirement. At frequencies well below cutoff with 1 Vpeak drive, modeling predicts that an unterminated link has negligible power consumption and 0 dB voltage loss, while a terminated link has 5 mW power consumption and 6 dB loss. For an unterminated link, simulations indicate that using a 25 micron-square bump instead of a 1 mm-long wire bond doubles the low-power bandwidth from 9 GHz to 18 GHz.This presentation will cover the architecture and technical challenges of this HI activity, describe the constituent InP and CMOS technologies, provide updated results from wirebonded and flip-chipped test prototypes, and discuss future opportunities for scaling and improved performance.Supported by the Laboratory Directed Research and Development program at Sandia National Laboratories, a multimission laboratory managed and operated by National Technology and Engineering Solutions of Sandia LLC, a wholly owned subsidiary of Honeywell International Inc. for the U.S. Department of Energy’s National Nuclear Security Administration under contract DE-NA0003525. SAND2020-5502A Figure 1

(Invited) Heterogeneous Integration of Silicon CMOS Electronics and Compound Semiconductor Electronics for Miniature RF Photonic Transceivers

Heterogeneous Integration (HI) may enable optoelectronic transceivers for short-range and long-range radio frequency (RF) photonic interconnect using wavelength-division multiplexing (WDM) to aggregate RF signals, provide galvanic isolation, and reduce crosstalk and interference. Integration of silicon Complementary Metal-Oxide-Semiconductor (CMOS) electronics with InGaAsP compound semiconductor photonics provides the potential for high-performance microsystems that combine complex electronic functions with optoelectronic capabilities from rich bandgap engineering opportunities, and intimate integration allows short interconnects for lower power and latency. The dominant pure-play foundry model plus the differences in materials and processes between these technologies dictate separate fabrication of the devices followed by integration of individual die, presenting unique challenges in die preparation, metallization, and bumping, especially as interconnect densities increase. In this paper, we will describe progress towards realizing an S-band WDM RF photonic link combining 180 nm silicon CMOS electronics with InGaAsP integrated optoelectronics, using HI processes and approaches that scale into microwave and millimeter-wave frequencies.

Large-Scale Antitumor Screening Based on Heterotypic 3D Tumors Using an Integrated Microfluidic Platform.

Chemotherapy screening plays a crucial role in cancer drug discovery and clinical medicine. Although conventional methods have contributed greatly to macromanipulation of cell populations, profounder insights related to the tumor microenvironment require approaches for completing integrated cell-3D tumor micromanipulation, massive tumor simulation and production, and dynamic and high-throughput tumor analysis. In this study, we introduced an integrated microfluidic platform with multiparallel components for heterotypic 3D tumor reconstruction and antitumor screening. Sequential microfluidic manipulations including sample loading, precise localization, 3D tumor formation, chemical stimulation, on-chip analysis, and tumor recovery for off-chip assessment were permitted and experimentally confirmed in the device on the basis of facile and efficient pneumatic control. Heterotypic 3D tumors with tissue-biomimetic phenotypes can be produced in massive and size-uniform manners. Notably, we accomplished a screening-like chemotherapy assessment involving different heterotypic 3D tumors and antitumor drugs and demonstrated the versatility of the platform in large-scale tumor manipulation and analysis. This advancement in microfluidics has potential applications in the fields of oncology, pharmacology, and tissue engineering and provides insight into the construction of high-performance microsystems for drug development and cancer research.

Control of dynamic microsystems

This paper formulates and solves control problems for nonlinear microsystems which comprise micro-electromechanical devices, micromachined transducers and microelectronics. We perform a consistent dynamic analysis and coherent designs with a minimum level of simplifications using high-fidelity mathematical models. The proposed methodology enables practical implementation for multi-input/multi-output systems due to overall conceptual consistency, design coherence, computational efficiency, algorithmic effectiveness and hardware simplicity. Various issues in nonlinear analysis and control are examined and experimentally verified substantiating design concepts for high-performance microsystems. The reported findings are demonstrated for a proof-of-concept closed-loop electrostatic microactuator.

A Through-life Approach to Developing High-performance Microsystems

This paper presents an assessment of the feasibility of a through-life approach for the development of high performance microsystems (HPMs) – microsystems, or microelectromechanical systems (MEMS) designed to operate in extreme conditions. It introduces HPMs, and their applications and presents reliability as the main through-life challenge to their market growth. It characterizes reliability challenges in HPMs and details the current understanding of failure modes in HPMs. It describes progress in failure prediction in HPMs and discusses future challenges. Finally, it summarizes why a general Design for Reliability approach would be advantageous for HPMs and summarizes progress in implementing such an approach.

Board Level Reliability of Solder Joint with a Low CTE PCB

With increasing market demands of electric products for smaller, thinner, and faster, printed circuit board (PCB) are pushed to accommodate these requirements. A PCB with low CTE and high elastic modulus could be an alternative to be able to meet the requirements needed for the next generation of high-performance microsystems. In this study, the board level reliability test was performed to evaluate solder joint reliability of low CTE PCB and conventional PCB. Solder joint could be generated the failure due to stresses induced by large coefficient of thermal expansion (CTE) mismatch between silicon and printed circuit board (PCB) under temperature variation. Also, in daily use portable devices such as cellular phones, PDAs, and MP3 players, it is common for them to be subjected to accidental drop impacts resulting in damage and hence failures. Therefore, the reliability performance of solder joints during temperature cycling and drop test is a key issue and it was focused to obtain the board level reliability of solder joint on low CTE PCB. After board level reliability test, cross-section SEM and OM was done to analyze fracture modes of solder joint reliability.

Fabrication of Metallic Nanocomponents by Forging of Ni3Al-Nanoparticles.

ABSTRACTThe trend to manufacture components reduced in size at the micro- and nano-scale is obvious and is becoming more and more the state of art in designing actuators, sensors and chips. In recent years, nanoscale fabrication has developed considerably, but the fabrication of freestanding nanosize components is still a great challenge. The fabrication of metallic nanocomponents utilizing three basic steps is demonstrated here. First, metallic alloys are used as factories to produce a metallic raw stock of nano-objects/nanoparticles in large numbers. These objects are then isolated from the powder containing thousands of such objects inside a scanning electron microscope using manipulators, and placed on a micro-anvil or a die. Finally, the shape of the individual nano-object is changed by nanoforging using a microhammer to get specific geometries such as discs and more complex components such as gears and wheels in the near future. The almost cubic particles are essentially defect-free, therefore, provide very high strength (σ>2500MPa) in combination with excellent formability (|ϕ|>1,6). There are two approaches for forming these small particles. Upset forging is used to forge small discs (height<100nm) and to shape the nanoparticle in specific areas. Press forging into nano-dies is used to forge more complex structures. In this way free-standing, high-strength, metallic nanoobjects may be shaped into components with dimensions in the 100 nm range. By assembling such nano-components, high-performance microsystems can be fabricated, which are truly in the micrometre scale (the size ratio of a system to its component is typically 10:1).

High Density Metal–Metal Interconnect Bonding for 3-D Integration

3-D integration provides a pathway to achieve high performance microsystems through bonding and interconnection of best-of-breed materials and devices. Bonding of device layers can be accomplished by dielectric bonding and/or metal-metal interconnect bonding with a number of metal-metal systems currently under development. RTI has been investigating Cu-Cu and Cu/Sn-Cu interconnect processes for high density area array applications. The interconnect pad fabrication processes and the interconnect bonding conditions (pressure and temperature) required for the formation of low resistance (10's of mΩ), high yielding (≥99.98% bond yield), and reliable interconnects are described. The effects of thermal reliability testing (aging) on electrical connectivity and mechanical strength are presented. Results from the two metal-metal interconnect bonding systems are compared in terms of ease of assembly and small pitch (sub-15 μm ) scaling. Methods for obtaining high bond yield at smaller pitches are discussed.

A high-performance microsystem for isolating circulating tumor cells

A unique flow field pattern in a bio-functional microchannel is utilized to significantly enhance the performance of a microsystem developed for selectively isolating circulating tumor cells from cell suspensions. For high performance of such systems, disposal of maximum non-target species is just as important as retention of maximum target species; unfortunately, most studies ignore or fail to report this aspect. Therefore, sensitivity and specificity are introduced as quantitative criteria to evaluate the system performance enabling a direct comparison among systems employing different techniques. The newly proposed fluidic scheme combines a slow flow field, for maximum target-cell attachment, followed by a faster flow field, for maximum detachment of non-target cells. Suspensions of homogeneous or binary mixtures of circulating breast tumor cells, with varying relative concentrations, were driven through antibody-functionalized microchannels. Either EpCAM or cadherin-11 transmembrane receptors were targeted to selectively capture target cells from the suspensions. Cadherin-11-expressing MDA-MB-231 cancer cells were used as target cells, while BT-20 cells were used as non-target cells as they do not express cadherin-11. The attachment and detachment of these two cell lines are characterized, and a two-step attachment/detachment flow field pattern is implemented to enhance the system performance in capturing target cells from binary mixtures. While the system sensitivity remains high, above 0.95, the specificity increases from about 0.85 to 0.95 solely due to the second detachment step even for a 1 : 1000 relative concentration of the target cells.

Quality improvement in community health centres: the role of microsystem characteristics in the implementation of a diabetes prevention initiative

ObjectivesTo examine the role of microsystem characteristics in the translation of an evidence-based intervention (the Diabetes Prevention Initiative (DPI)) into practice in a community-health centre (CHC).DesignCase study.AnalysisConstant comparative method of...

The Accreditation and Certification System After Next

The Accreditation and Certification System After Next

CHALLENGES FACED IN PROVIDING SAFE CARE IN RURAL PERINATAL SETTINGS

To examine and describe neonatal resuscitation preparedness, presence of connections to wider systems of care, continuing education activities, presence of trained staff, and other indicators of high performance in rural perinatal microsystems. A nonexperimental, retrospective, descriptive, cross-sectional design was utilized. Rural hospitals (n = 124) providing perinatal services in five southern states were invited to participate. Nurse managers completed the Hospital Neonatal Resuscitation Survey, describing policies, healthcare team members, educational activities, organizational culture, system connections, and process improvement. Descriptive data were also collected. A total of 44 (35.1%) hospitals participated. Annual birth volume ranged from 22 to 1,614 (M = 515.53; SD = 336.27). Low birth volume hospitals (<125 births per year) had significantly lower levels of preparedness than high volume hospitals (>125 births per year). Preparedness was not influenced by rurality. One-third (34.1%) did not identify relationships with Level III NICUs. Support of continuing education was universal. Efforts to increase interdisciplinary teamwork were common. Medical provider shortages were prevalent (n = 25: 56.8%), and the presence of midwifery services was infrequent (n = 12; 27.2%). Hospital nursing shortages (n = 35; 81.8%) were widespread. Challenges faced by rural hospitals and healthcare professionals in the delivery of perinatal care emphasize the importance of creating and maintaining high performance microsystems that are responsive to the changing needs of providers and the populations they serve. Lower levels of preparedness and the lack of established relationships with level III NICUs is concerning.

The Impact of a Quality Improvement Program on Employee Satisfaction in an Academic Microsystem

Quality improvement is a potential method to enhance employee satisfaction. This study describes the impact of a program instituted to enhance employee satisfaction using the principles of high-performing microsystems. A shared leadership committee, participatory meetings, suggestion boxes, and quality improvement projects were implemented as part of the program. A follow-up survey 1 year after implementation of the program demonstrated an increase in employee perception of the division's desire to improve service (16%), opportunities to expand skills (17%), involvement in work decisions (25%), and the institution's interest in employee well-being (17%). Key drivers of discretionary effort (4 of 5), job satisfaction (2 of 6), and overall satisfaction (1 of 8) with the institution showed statistically significant improvement in the study division as compared with the other divisions in which no such program was implemented. Further research is needed to study systems changes that enhance employee satisfaction and their impact on patient and financial outcomes.

Forging of metallic nano-objects for the fabrication of submicron-size components

In recent years, nanoscale fabrication has developed considerably, but the fabrication offree-standing nanosize components is still a great challenge. The fabrication of metallicnanocomponents utilizing three basic steps is demonstrated here. First, metallic alloys areused as factories to produce a metallic raw stock of nano-objects/nanoparticles in largenumbers. These objects are then isolated from the powder containing thousands of suchobjects inside a scanning electron microscope using manipulators, and placed on amicro-anvil or a die. Finally, the shape of the individual nano-object is changed bynanoforging using a microhammer. In this way free-standing, high-strength, metallicnano-objects may be shaped into components with dimensions in the 100 nm range. Byassembling such nanocomponents, high-performance microsystems can be fabricated, whichare truly in the micrometre scale (the size ratio of a system to its component is typically10:1).

CONTROL STRATEGY FOR MEASUREMENT PERFORMANCE ENHANCEMENT OF A MICROMACHINED ACCELEROMETER

This paper presents the design of a closed-loop micromachined accelerometer using a sensitivity functions shaping approach in order to reach the desired measurement performance. The controller design is based on an identified model of the plant (MEMS, readout circuit and actuator) and a pole placement strategy. Simulation results and real-time application on a prototype show the feasibility and the interest of this methodology for high performance microsystem design.

Microsystems in health care: Part 4. Planning patient-centered care.

Clinical microsystems are the essential building blocks of all health systems. At the heart of an effective microsystem is a productive interaction between an informed, activated patient and a prepared, proactive practice staff. Support, which increases the patient's ability for self-management, is an essential result of a productive interaction. This series on high-performing clinical microsystems is based on interviews and site visits to 20 clinical microsystems in the United States. This fourth article in the series describes how high-performing microsystems design and plan patient-centered care. PLANNING PATIENT-CENTERED CARE: Well-planned, patient-centered care results in improved practice efficiency and better patient outcomes. However, planning this care is not an easy task. Excellent planned care requires that the microsystem have services that match what really matters to a patient and family and protected time to reflect and plan. Patient self-management support, clinical decision support, delivery system design, and clinical information systems must be planned to be effective, timely, and efficient for each individual patient and for all patients. Excellent planned services and planned care are attainable today in microsystems that understand what really matters to a patient and family and have the capacity to provide services to meet the patient's needs.

The heterogeneous integration of optical interconnections into integrated microsystems

Emerging techniques for integrating optoelectronic (OE) devices, analog interface circuitry, RF circuitry, and digital logic into ultra-mixed signal systems offers approaches toward and demonstrations of integrated optical interconnections in electrical microsystems. As rising data rates dictate the use of optical interconnections and interfaces at increasingly smaller distances, optical interconnections stand at a threshold of opportunity for pervasive implementation if cost-effective integration process technology and performance can be implemented. Heterogeneous integration is one approach toward the integration of compound semiconductor OE devices, Si CMOS circuits, and organic materials. Heterogeneous integration approaches, which utilize dissimilar materials which can be independently grown and optimized, and are subsequently bonded together into an integrated system, are particularly attractive methods for creating high-performance microsystems. This paper describes a variety of optical interconnections integrated into microsystems using thin film heterogeneous integration. Thin film heterogeneous integration is attractive from the standpoint that the topography of the integrated microsystem can remain flat to within a few microns, substrates which are often optically absorbing are removed, both sides of the thin film devices can be processed (e.g., contacted, optically coated), and three-dimensionally stacked structures can be implemented. Demonstrations of interconnections using thin film heterogeneous integration technology include an integrated InGaAs/Si CMOS receiver circuit operating at 1 Gbps, an InGaAs thin film photodetector bonded onto a foundry Si CMOS microprocessor to demonstrate a single chip optically interconnected microprocessor, smart pixel emitter and detector arrays using resonant cavity enhanced P-i-N photodetectors bonded on top of per-pixel current controlled oscillators and resonant cavity enhanced light emitting diodes integrated onto digital to analog converter gray-scale per-pixel driver circuitry, and photodetectors embedded in waveguides on electrical interconnection substrates to demonstrate chip-to-chip embedded waveguide interconnections.

Chip-to-Module Interconnections Using “Sea of Leads” Technology

AbstractThe drive toward higher density and higher performance in integrated circuits creates a need to keep interconnects short and eliminate layers of packaging. In this article, we propose a novel, ultrahigh-density (exceeding 104leads per cm2), compliant, wafer-level, input/output interconnection technology called “sea of leads” as a key enabling technology for future high-performance microsystems. The mechanical compliance is addressed through slippery leads (leads released from the surface) and embedded air gaps. The ability to fabricate embedded air gaps has enabled the integration of optical interconnects with high index-of-refraction mismatches between the core and cladding.

Anforderungen der Mikrosystemtechnik an die Materialforschung/ The Materials Research Requirements of Microsystems Technology

In addition to intelligent information processing, high performance microsystems also need microsensors and microactuators. Manufacturing such components requires both the adaptation of well known materials for use in the micrometer range as well as the development of brand new materials. This article describes the materials research carried out in the field of microsystems technology with reference to three examples of work undertaken at the Forschungszentrum Karlsruhe. So called Smart Materials are now commonly used in many new types of microsensors and -actuators. For example, with magnetostrictive thin films, a considerable improvement in the efficiency of micromotors and torque sensors can be achieved using multi-layer films. High performance microspectrometers now used in many new applications can be made from plastics thus taking advantage of very cost effective moulding techniques. The high precision moulding tools for these are made using deep X-ray lithography and micro-electroplating (LIGA process) in which the metallic microstructure and thus the hardness of the tool can be significantly influenced by the plating conditions used. High performance micropumps are also made by a combination of thin film technology, high precision adhesive bonding techniques and plastic moulding.