Karla Hiller

• Professor at Chemnitz University of Technology

Thin metal layers such as silver (Ag) are being utilized for various optical and plasmonic applications as well as for electrical purposes, e.g., as transparent electrodes in display devices or solar cells. This paper focuses on optical MEMS applications such as the Fabry–Pérot interferometer (FPI). Within such filters, reflector materials such as...

This paper reports the development and integration of (Poly‐Si/Air)ⁿ Distributed BRAGG Reflectors (DBR) in a MOEMS Fabry‐Pérot‐Interferometer (FPI) concept. The realized reflectors constitute a promising and resource‐efficient alternative to complex Ion‐Assisted Deposition based DBRs while maintaining their advantages. Compared to state of the art...

This paper presents a technique for selective and energy-efficient induction heating of aluminum (Al) frames to support and enhance the thermocompression bonding (TCB) for electronics packaging in the field of heterogeneous integration. The technological challenges include the use of an adapted induction coil for homogeneous heat distribution, the...

In this article, an efficient die-bonding technology based on silver sintering due to induction heating is presented. By using this technology, the heat for the sintering reaction is locally limited to the bonding area and heating of the entire power module is avoided. Furthermore, the sintering reaction is promoted due to current flow between the...

In this article, an efficient die bonding technology based on silver sintering due to induction heating is presented. By using this technology, the heat for the sintering reaction is locally limited to the bonding area and the heating of the entire power module is avoided. Furthermore, the sintering reaction is promoted due to current flow between...

Flip chip bonding is a widely used method in 3D integration. In this study, the use of electroplated Aluminum as pillar structure for ultrasonic flip chip bonding is demonstrated for the first time. Al pillars were deposited from a chloroaluminate ionic liquid on a 6 inch silicon wafer. The influences of ultrasonic bonding parameters (bonding time,...

Flip chip bonding is a widely used method in 3D integration. In this study, the use of electroplated Aluminum as pillar structure for ultrasonic flip chip bonding is demonstrated for the first time. Al pillars were deposited from a chloroaluminate ionic liquid on a 6 inch silicon wafer. The influences of ultrasonic bonding parameters (bonding time,...

Considering the demand for low temperature bonding in 3D integration and packaging of microelectronic or micromechanical components, this paper presents the development and application of an innovative inductive heating system using micro coils for rapid Cu-Sn solid-liquid interdiffusion (SLID) bonding at chip-level. The design and optimization of...

Piezoelectric micromirrors with aluminum nitride (AlN) and aluminum scandium nitride (Al0.68Sc0.32N) are presented and compared regarding their static deflection. Two chip designs with 2 × 3 mm2 (Design 1) and 4 × 6 mm2 (Design 2) footprint with 600 nm AlN or 2000 nm Al0.68Sc0.32N as piezoelectric transducer material are investigated. The chip with...

Next to powders, inks, and microelectronics, many technologies that carry the attribute nano in their name are still waiting for their breakthrough and wide acceptance in engineering and industry. At least nanofabrication technologies are the subject of a vivid track in research and development in a variety of scientific fields but yet most of them...

This paper presents several approaches for bonding at low temperature with a resulting interface alloy that is stable at temperatures higher than the bonding temperature itself. The bonding principle described herewith is called Solid Liquid Interdiffusion (SLID) bonding, where two metals were used for creating an alloy. First, a low melting point...

A 2D scanning micromirror with piezoelectric thin film aluminum nitride (AlN), separately used as actuator and sensor material, is presented. For endoscopic applications, such as fluorescence microscopy, the devices have a mirror plate diameter of 0.7 mm with a 4 mm² chip footprint. After an initial design optimization procedure, two micromirror de...

In this work, aluminium scandium nitride (Al1−𝑥Sc𝑥N) thin films are deposited by reactive DC magnetron co-sputtering on Pt(111) layers. The sputtering power of the Sc target is varied in a broad range up to 900 W to effectively vary the Sc content later assessed using energy-dispersive X-ray spectroscopy (EDX). We show that commonly used X-ray diff...

This paper reports on the improved micro- mechanical structures and improved integrated electronics to create high bandwidth acceleration sensors with a high signal to noise ratio and very low power electronics. This ambitious aim can be achieved by a very close co-design of MEMS and ASIC. Our two axis micromechanical element is optimized with resp...

More and more smart components and smart integrated systems enter into diverse innovative products and applications. They are key components and key technologies for industry 4.0 as well as Internet of Things and Services. The application areas include not only smartphones with advanced functionalities but also monitoring systems for sustainable pr...

MEMS based devices have a huge potential in different monitoring applications ranging from environmental control to medicine. This paper shows principles and advantages of two miniaturized NIR/IR-spectrometers, based on different MEMS technologies. Small size, portability and cost efficiency as well as high accuracy and mechanical robustness make b...

Micromachined tunable Fabry-Pérot filters (μFPF) are key elements in a new class of miniature spectrometers and analyzers. Different groups all over the world are working on μFPF for spectral ranges from the visible up to the long wave infrared. In order to achieve a large tuning range, the filters are normally operated in the first interference or...

This paper presents a novel tunable infrared filter applying a subwavelength grating that substitutes the distributed Bragg reflectors (DBRs) in tunable Fabry-Perot (FP) filters to reduce cost and fabrication effort. It consists of uniformly arranged disc resonators which are made of 100 nm thick aluminum at a 200 nm Si3N4 membrane carrier that sta...

Dieser Artikel beschreibt technologische Weiterentwicklungen und Anwendungen der sogenannten BDRIE-Technologie (Bonding and Deep RIE) als Si-Si bzw. Si-Glas-Variante zur Herstellung präziser Sensoren und Aktuatoren. Die technologischen Weiterentwicklungen betreffen insbesondere die optionale Integration vertikal gestufter Elektroden, unterliegender...

As is generally known, miniature infrared spectrometers have great potential, e. g. for process and environmental analytics or in medical applications. Many efforts are being made to shrink conventional spectrometers, such as FTIR or grating based devices. A more rigorous approach for miniaturization is the use of MEMS technologies. Based on an est...

This paper reports on the application of sub-wavelength structured single layer reflectors in a Fabry-Perot-Interferometer (FPI) that are used in order to replace distributed Bragg reflectors (DBR). A pair of two-dimensional arrays of ring resonators was analyzed. A 100 nm thin Al layer is regularly patterned to form a meta-surface structure. It sh...

In this paper a MEMS based micro-SPM head array is proposed to enhance the performance of the currently available nano-measuring machines and effectively reduce the measurement time for large specimen. It consists of 1 × N ( N = 7 in our case) micro-SPM heads/units, realized in one chip by MEMS technique. And it can be easily extended to a micro- S...

A tunable dual-band MEMS Fabry-Pérot filter for simultaneous use of the spectral ranges from 8 µm to 10.5 µm and from 4 µm to 5 µm is reported. A peak transmittance of at least 75 % and a FWHM of less than 200 nm were measured. The maximum control voltage is 41 V. Two movable reflector carriers compensate the influence of gravitational force on the...

A novel MEMS based scanning head comprising an array of comb drive actuators is developed for parallel SPM (Scanning Probe Microscope) imaging to enhance the performance of the currently available nano-measuring machines and effectively reduce the measurement time for large specimen. The scanning-head consists of an row of seven scan heads, which a...

A tunable IR filter based on a Fabry-Perot interferometer with two movable reflectors is reported. The infrared filter can be tuned over a wavelength range from 8 mum to 11 mum with voltages lower than 63 V. The FWHM bandwidth is lower than 200 nm and the peak transmittance is larger than 70 %. Simulation and practical shock test, both showed that...

As a result of the growing complexity and miniaturization of innovative products systems integration is becoming more and more important for scientific and technical development. The micro and nano system technologies as well as electronics are playing a key role in today's product development and industrial progress. They enable the integration of...

The micro and nano system technologies as well as electronics are playing a key role in today's product development and industrial progress. They enable the integration of mechanical, electrical, optical, chemical, biological and other functions into a very small space with dimensions ranging from sub micrometers up to some millimeters. This paper...

In this paper we describe the design, the fabrication and the properties of tunable MEMS Fabry-Pérot (FP) filters for the long-wave infrared range (LWIR). Based on a mid-wave IR (MWIR) device, completely new optical and electro mechanical designs have to be used to extend the spectral range to the LWIR. A new set of optical thin films with low and...

This work deals with the replacement of the reflection layer stacks by sub-wavelength structures, which form the cavity of Fabry-Perot-Interferometer (FPI) infrared filters. Periodically arranged metal ring resonators are investigated regarding reflectivity and sensitivity with respect to polarization angle by Finite Difference Method (FDM) analysi...

A low-cost, polymer-based microfluidic platform is described that not only includes passive microfluidic parts, but also pumps based on an on-chip electrochemical gas generation by electrolysis. A hydrogel is used as electrolyte material, which allows a simple fabrication process by screen printing or stencil printing. Test structures were designed...

First results of a MEMS Fabry-Perot filter (FPF) for the spectral range of 8-11 mum are presented. Broad bandwidth and a low phase dispersion could be achieved by using new dielectric materials with an enhanced refractive index contrast and relatively simple reflector designs with a low number of layers. Different designs of the Bragg reflectors an...

In this paper we present basic designs, operation concepts and some application examples of a novel microspectrometer for the spectral range of 3-5mum, which is based on a pyroelectric detector with an integrated micromachined Fabry-Perot filter (FPF). We discuss the influence of different optical setups on the spectral resolution and the signal-to...

Micromechanical resonators for vibration sensing are typically limited to frequencies above 1 kHz [D. Scheibner, J. Mehner, D. Reuter, T. Gessner, W. Dötzel, A spectral vibration detection system based on tunable micromechanical resonators, Sens. Actuators A 123–124 (2005), 63–72]. A novel method for resonant vibration detection at lower frequencie...

As more and more protein disease markers are identified, protein-compatible Labon- Chip platforms for point-of-care diagnostics are desired and currently under investigation. The development of a microfluidic system for protein detection requires careful attention to the specific properties of proteins. To ensure a high sensitivity, it is of partic...

An improved process for the fabrication of capacitive ultrasonic transducer is proposed. The transducer consists of a membrane carrier and a recessed substrate. It is assembled together through a newly developed direct bonding technology. Benefited from the separate component preparations, low frequency transducers of 100 to 500 kHz can be realized...

This paper reports design, fabrication and test results of a tunable pyroelectric detector with an integrated micromachined Fabry-Perot (FP) filter for gas analysis in the Mid-Wave Infrared (MWIR). The new approach is based on a bulk micromachined Fabry-Perot interferometer with an air cavity, which is electrostatically tuned. Various types of move...

This contribution describes the investigation of the reasons for overload failure and overload reaction based on linear vibration theory by decomposition of the complex reaction into resonant mode reactions and on observation of the reaction. An impulse specific peak deflection (ISPD) is derived as a general characteristic property of a certain sho...

Self-containing microfluidic low-cost cartridges have been developed. Fully in-tegrated, the platform provides on-chip immunoassays complete with micropumps and reagents. The operational performance of the system is designed so that only an electric interface to the outside world is necessary. INTRODUCTION To transfer protein assays from the labora...

This paper describes a new technology platform for polymeric micro optical fluidic systems. The platform consists of active and passive optical and fluidic elements for a surface plasmon resonance (SPR) biosensor for the detection of proteins. The platform includes the integration of polymer light emitting diodes, polymer photodiodes as well as pol...

Infrared spectra of multiple frustrated total internal reflection and transmission for silicon wafers obtained by direct bonding in a wide temperature range (200–1100°C) are studied. Properties of the silicon oxide layer buried at the interface are investigated in relation to the annealing temperature. It is shown that the thickness of the SiO2 lay...

Der Siegeszug der Mikroelektronik ist faszinierend. In den vergangenen Jahrzehnten bestimmte die Mikroelektronik das Geschehen in der Informationstechnik: Immer leistungsstärkere Computer, vernetzte Systeme und das Internet sind ohne Mikroelektronik nicht denkbar. Weltweit haben Mikroelektronik-Firmen ihre strategischen Ziele im Rahmen einer in reg...

This contribution deals with the design, fabrication and test of a micromachined first order Fabry-Perot (FP) filter that is intended for use in advanced infrared gas analysis. To achieve optimal interference conditions within an FP filter, the roughness and the curvature of its reflectors must be minimized, while the parallelism between reflectors...

This paper presents the whole process of building up a high precision, high dynamical MEMS acceleration sensor. The first samples have achieved a resolution of better than 500 ug and a bandwidth of more than 200 Hz. The sensor fabrication technology is shortly covered in the paper. A theoretical model is built from the physical principles of the co...

This paper describes the application of a micromachined resonator to verify the vacuum pressure and sealing of cavities in micromechanical components. We use an electrostatic driven and capacitively sensed bulk silicon resonator fabricated by Bonding and Deep Reactive Ion Etching (BDRIE) technology. The resonator operates at the first fundamental f...

In this paper we present the very promising results for two methods of the so-called Bonding and Deep RIE (BDRIE) technology, characterised by bonding of two wafers with pre-patterned vertical gaps and subsequent RIE trench etching of the active layer. In case of the anodically bonded silicon-glass compound detection electrodes for vertical movemen...

Vorgestellt wird ein kompaktes, durchstimmbares Infrarotfilter, welches als Fabry–Perot-Interferometer (FPI) in 1. Ordnung für den Spektralbereich (3...5) μm ausgebildet ist. Das Filter ist mikromechanisch aus doppelseitig polierten, 300 μm dicken Si-Wafern gefertigt. Die Si-Wafer werden nasschemisch strukturiert und durch Waferbonden gefügt. Als R...

This work is a contribution to technology development of capacitive microsensors with moved components, such as vacuum pressure sensors and angular rate sensors. It describes the sensor principles, Si microfabrication technologies and test results of prototypes.

This contribution deals with design, fabrication and test of a micromachined Fabry-Perot-Interferometer in first order configuration. Main application fields are chemical analysis, infrared sensing and spectral imaging. Some of the most important properties of a FPI filter are the full width half maximum (FWHM) and the tunable spectral range which...

Non-destructive multiple internal transmission and multiple internal reflection infrared (IR) measurements were used to investigate the silicon wafer bonding process. IR measurements performed ex situ and in situ reveal the chemical reactions which take place during annealing at the interface of silicon bonded wafers with thin native (Si/Si) or thi...

Silicon is the dominating material for the fabrication of MEMS devices, especially in high volume production. However, metals with their typical properties are used to enhance or enable the functionality of MEMS. In contrast to microelectronic technologies, not only the electrical but also the mechanical and optical behavior of metals could be help...

This contribution deals with design, fabrication and test of a micro-machined first order Fabry-Perot interferometer (FPI) that is intended for use as a tunable infrared (IR) filter in the (3-5)μm band. The approach here minimizes mirror curvature by using 300 μm thick silicon (Si) mirror carriers for the coplanar fixed and movable mirrors of the F...

This paper summarizes two novel technology approaches for advanced Silicon micro machining of MEMS devices and presents applications using these processes. These MEMS devices are Atomic Force microtip structures, tunable Fabry-Perot-Filters for IR spectral range and integrated micro mirror arrays for Hadamard transform optics. Process characteristi...

This contribution deals with the design, fabrication and test of a micro-machined first order Fabry- Perot Interferometer (FPI) that is intended for use as a tunable infrared (IR) filter in many applications, including IR spectrometers. To achieve optimal interference conditions within an FPI, the curvature of its internal mirrors must be minimized...

This contribution deals with design, fabrication and test of a micromachined gauge for vacuum pressure as well as with the related electronics. An electrostatically driven and capacitively sensed Si tuning fork is operated at the fundamental resonance frequency. The damping is used as a measure of the pressure. We use bulk micromachining with two s...

A multiple internal transmission (MIT) technique was used for infrared (IR) spectroscopic investigations during annealing of the interfaces in room temperature Si-Si bonded wafers with different chemical pre-treatments. The evolution with annealing temperature of the chemical species at the interface are used to explain the bonding mechanism of Si...