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Holger Vogt - IEEE Xplore Author Profile

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This study reports on the development of vertical, partially encapsulated nanoelectrodes for electrically contacting the interior of electrogenic cells with microelectronics. Intracellular electrical stimulation and recording with single cell resolution enables new insights into the electrophysiology of cells embedded in a complex multicellular network, providing detailed understanding of fundamen...Show More
In this letter, a thermal conduction measurement method for thermal radiation sensors, such as vacuum-packaged bolometers, is presented. The idea of the method is deduced from the classical 3ω-method proposed by Cahill [1]. Here, the measurement geometry is a complete sensor geometry, which is suspended from the substrate by thermal isolation legs. The most relevant performance factor for such a s...Show More
In this work, the hermeticity of diaphragm structures is investigated and optimized. The diaphragms are developed for the monolithic post-CMOS integration of capacitive pressure sensors. Si1-XGeX is used as diaphragm material and was deposited at temperatures below 400 °C.The hermeticity of the diaphragms was evaluated at a He pressure of 1800 hPa and in a temperature range from 50 °C to about 100...Show More
In this work, a concept and proof of principle regarding a fabrication technique for vertical nanoelectrodes is presented. CMOS-compatible processes for the fabrication of three-dimensional tubes which are partly encapsulated by an insulation layer are conceived. An extended sacrificial layer technique using deep reactive ion etching (DRIE) and atomic layer deposition (ALD) of encapsulation and el...Show More
To further optimize micro pellistors and reduce the required chip area, one possibility is to fabricate the sensor on top of the integrated circuit (IC). Therefore, a sacrificial layer process developed by the Fraunhofer IMS combining deep reactive ion etching (DRIE) and atomic layer deposition (ALD) is modified. First fundamentals of pellistors and Joule heating are described. Then simulations to...Show More
Understanding the mechanical behavior of free standing membranes is a point of common interest for MEMS structures, where a certain distance or deflection of a cantilever or membrane refers directly to the detectors performance. A material system with different types of basic MEMS materials like doped silicon as well as a conducting and passivation layer was characterized. Mechanical stress was me...Show More
Size reduction in microelectromechanical systems (MEMS) leads to more complex behavior of physical parameters affected by quantum mechanical effects. Besides specific electrical resistance, thermal conductivity is a characteristic parameter for designing application-specific MEMS. Nanotubes are able to realize an electrical contact between a sensor element and a CMOS substrate while providing suff...Show More
This work presents the analysis of the minimum actuation voltage Vmin for droplet actuation with electrowetting on dielectric (EWOD). First, the fundamentals of electrowetting are described. In the second chapter, the impact on the actuation voltage in EWOD is shown by a dielectric deposited with atomic layer deposition (ALD) and micro-structured surface. In the last part, results of a simulation ...Show More
We present several contributions of our test system to detect multiple targets with the direct time-of-flight technique. With a precise time-to-digital-converter it is possible to capture the time-of-flight of a short light pulse reflected by a target with high temporal resolution. Based on this technique we can relate the single events to its resulting distance and separate the different objects.Show More
Physically Unclonable Functions (PUFs) are a new type of hardware-bounded cryptographic primitives. PUFs leverage random process variations to generate unique keys suitable for the use in low-cost device identification and authentication applications. Since the keys are typically derived from a large number of semiconductor devices, a space- and power-saving implementation of PUFs in non-volatile ...Show More
This article presents the simulation results and design rules of a new sensor for infrared (IR)-detection using the thermoelectric effect. Within the Seebeck effect, thermopiles generate a voltage based on a temperature gradient inside the structure. State-of-the-art thermopiles are manufactured as 2-D structures directly on a substrate. Here, a possible method of 3-D integration is shown, where t...Show More
Physically Unclonable Functions (PUFs) offer enticing possibilities to incorporate hardware-based security on semiconductor device level. In order to make efficient use of PUF functionality in lightweight cryptographic applications, a low-overhead implementation in terms of chip area and power consumption is required. In this paper a fully differential readout circuit is proposed that allows the g...Show More
The understanding and controlling of semiconductor process variation is crucial to the performance, functionality and reliability of modern ICs. Due to the complex fabrication process involving hundreds of processing steps, the analysis of the sources of variability is a non-trivial task. In this paper, a novel, simple-to-implement procedure named Hierarchical Median Polish is proposed. The method...Show More
Fraunhofer IMS develops and fabricates far-infrared focal plane arrays (IRFPA) using microbolometers with a pixel pitch of 17μm technology realized on top of a 0.35 μm CMOS readout integrated circuit (ROIC). The microbolometers are encapsulated by a Chip-Scale-Package (CSP) to ensure a high quality vacuum level. The CSP is realized by placing an infrared transparent lid above a solder frame surrou...Show More
To realize an intracellular contact between nanoelectrodes and cells, a sufficient small electrode diameter is needed [1]. A sacrificial layer process developed by the Fraunhofer IMS using deep reactive ion etching and atomic layer deposition [2] is varied. A double hard mask technique is used to taper structures in a sacrificial layer and thereby the nanoelectrodes' diameter. The principles and e...Show More
Passive components like capacitors for harsh environments become more and more important, e. g. in the field of deep drilling, aerospace or in the automotive industry. They have to withstand temperatures up to 300 °C with a good performance concerning leakage current, breakdown voltage and capacitance density. The whole process flow has to be CMOS-compatible in order to offer the possibility for C...Show More
The level of security provided by physically unclonable functions (PUFs) strongly depends on the unpredictability of its challenge-response behavior. Systematic variation in the properties of a PUF might introduce correlations in the output bits. The mutual dependence of response bits is typically not detected by conventional methods, thus leaving the PUF vulnerable to prediction attacks. New meth...Show More
This paper gives an overview of technologies and materials for microsystems and electronics in harsh environmental applications including the fabrication of a multifunctional MEMS with platinum metallization, high-temperature stable CMOS circuits and trench capacitors, ceramic-based packaging technologies as well as analysis of material parameters, simulation and reliability testing.Show More
We investigated the leakage current of thin film silicon-on-insulator (SOI) pin-diodes in dependence of the back-gate potential and hot carrier induced traps. Leakage current of virgin and hot-carrier stressed diodes was measured at distinct back-gate potentials. TCAD simulations were used to determine the mechanisms of leakage current generation at specific back-gate potentials. Traps were introd...Show More
We report on an electrochemical measurement setup comprising a glucose sensor and a CMOS potentiostat with a two-layer membrane as the first steps toward the development of an integrated in-situ sensor system for bioreactors. The potentiostat has a chip size of 2.1 mm × 2.5 mm and a linear current range from -220 nA to 240 nA with a linearity of R2 = 0.9995. For wide range measurements of glucose ...Show More
This paper deals with the reliability of a 1.0- μm CMOS-silicon-on-insulator (SOI) process, which is intended for use at 250 °C. The goal is to give an overview of the most important reliability aspects that concern devices and circuits at temperatures of 250 °C and above. The investigated reliability aspects are the gate oxide integrity in terms of time-dependent dielectric breakdown measurements...Show More
Recently a 128×96 pixel range imager with a pitch of 40 μm and a fill factor of 38 % was presented for 3D range imaging measurements based on the pulse modulated (PM) time-of-flight (ToF) principle. This sensor employs a high-speed photodetector called lateral drift-field photodiode (LDPD). During the characterization insufficiencies in charge transfer were observed for low-light illumination. Her...Show More
This paper presents a novel fully implantable wireless sensor system intended for long-term monitoring of hypertension patients, designed for implantation into the femoral artery with computed tomography angiography. It consists of a pressure sensor and a telemetric unit, which is wirelessly connected to an extracorporeal readout station for energy supply and data recording. The system measures in...Show More
We present quantum efficiency (QE) and quantum yield (QY) measurements of novel deep optical stack etching extreme-ultraviolet complementary metal-oxide-semiconductor photodiodes of different sizes and derive future potentials. QE values between 24% and 50% at 13.5 nm were achieved. Variations in QE and QY measurement results were analyzed.Show More
In recent years CMOS image sensors have gained a major market share for general imaging applications. However, when standard CMOS image sensors are employed in applications that require the detection of light with a very small spectral width, like 3D-time-of-flight imaging or other applications with laser light illumination, problems arise, that are negligible in standard imaging applications with...Show More