H. Gerdes

Fraunhofer Institute for Surface Engineering and Thin Films IST | IST · Highly Ionized Plasmas and PECVD

Sputter deposition of magnetic material provides some challenges. In the case of soft magnetic materials, usually thin targets and strong magnetic arrays of the sputtering cathode are used for an effective magnetron sputtering. In the case of hard magnetic material, the situation is different. The magnetic field lines are closed in the target and t...

High power impulse magnetron sputtering (HIPIMS) allows the deposition of thin films from plasmas with high metallic ion content. For several applications, indium tin oxide (ITO) films were successfully deposited by HIPIMS from planar ceramic targets, e.g. for ice-free windshields or shaped glass tubes. These films present good conductivity as well...

Aluminum oxide (Al2O3) thin films are used in microelectronics and sensor applications due to their good insulating properties. Usually, RF sputtering processes are used to produce insulating coatings for sensors, but this process has major drawbacks, mainly, a very low deposition rate which leads to higher production costs. AC reactive sputtering...

This paper reports on design of a micro linear tristable actuator with an integrated sensor platform. On the basis of theoretic analysis and previous works, a novel design for the set-up of the one-axis actuator is proposed, in which electromagnetic driving is used. It consists of a slider carrying the movable structure to which the actuated compon...

Highly ionized pulse plasma processes (HIPP processes) like High Power Impulse Magnetron Sputtering HIPIMS and Modulated Pulse Power MPP have matured in recent years. Current research focuses on the development for industrial processes. HIPP processes offer a tool for tailoring the film properties and to improve hardness, density, refractive index,...

High power impulse magnetron sputtering (HIPIMS) pulses have been of great interest over the last decade. With such sputtering techniques a substantial amount of target material can be ionized and used for the engineering of surfaces and coatings. Depending on voltage, system configuration and target material, such discharges can be either transien...

Commercial strain gauges obtain a gauge factor of approximately 2 with a compensated temperature coefficient of resistivity (TCR). Therefore, material development for sputtered thin films with a high gauge factor and negligible TCR was conducted. The object for self compensated sensor materials is the combination of a semiconducting material (negat...

Since excessive stress in deposited thin-films may result in a delamination of these films, a low internal stress level is desirable. State of technology for measuring internal stress in bulk materials is the hole-drilling method. This paper investigates the application of the hole-drilling method to thin-films using a focused ion beam (FIB) for cr...

In many industrial applications strain gauges are commonly used for measurements of applied forces or the loading status of work pieces. While commercial strain gauges using polyimide foils can cause errors due to influence of humidity, directly applied thin film strain gauges avoid this problems. Besides the improvement of the signal due to avoidi...

Achieving the specified magnetic properties of magnetic thin- films is a precondition for a successful wafer fabrication of magnetic thin-film devices. In many cases, these films are anisotropic, with two main axes (hard and easy) perpendicular to each other. For a wafer level measurement along these axes, a new test approach is suggested: employin...

This paper presents a concept and a feasibility study for the development of a magnetoelastic sensor based on the Villari effect for determining mechanical stresses inside carbon fibers reinforcing composite materials. For determining the fiber's mechanical load within the interface, the fiber will be covered with a thin film of magnetoelastic NiFe...

We present 63Cu NMR studies of the CuO2 chains in Sr13LaCu24O41 and Sr14Cu24O41. In both compounds the temperature dependence of the NMR frequency shift is described by an antiferromagnetic dimer model for the local susceptibility. For Sr14Cu24O41 the resulting spin excitation gap (133 K) is consistent with macroscopic susceptibility and inelastic...