A sensor which detects mechanical stresses and stores the position and the strength of these loads by color change of embedded quantum dots (QDs) is presented. The top and bottom electrodes of the sensor are inkjet-printed which leads to a fast and accurate deposition of thin (approx. 50 - 300 nm) and conductive layers. The used silver and poly(3,4-ethylenedioxythio-phene) polystyrene sulfonate (PEDOT:PSS) inks are optimized in terms of printability and opportunities of functionality forming without influencing the active layer of the sensor. The active layer of the sensor is spin-coated and consists of the QDs embedded in semi-conducting poly(9-vinylcarba-zole) (PVK). The hole transport characteristic of PVK and the band level alignment of the used materials ensures the preferred injection of only one type of charge carrier into the QDs. As a result the mechanical stress is visualized by a decreasing in photoluminescence (PL) of the QDs.

This paper reports on the ohmic contacts of an radio-frequency micro-electro-mechanical-system (RF MEMS) switch. The structure of the MEMS is described briefly to give information about the organization of the switch device. The most significant performance data are reported, indicating very low actuation voltage below 5 V, switching time of <10 µs and good RF performance for frequencies up to 5 GHz. Since the contact performance is a key for excellent RF performance in the actuated state and for high reliability as well the article is focused on the contacts. It is supposed that asperities are building the current path in a closed contact, which is proved by measurements of the closing process with high time resolution. The measurements exhibit very good power-handling capabilities of the contacts. The reported findings render prior theoretical experiments with a physical device.

This paper describes a three-step process regime for the integration of porous SiCOH based ultra low-k materials in existing copper damascene technologies. During the work with these complex and sensitive materials, it became more and more clear, that a successful patterning depends not only on the etch step but also on the adjustment between the etch and the following cleaning and k-restore processes. The presented process regime starts with a reactive ion etch process for trench patterning followed by a post etch clean to remove etch residues. Finally a k-restore process was performed to repair the damaged regions in the trench sidewalls. In this work it became clear, that the etch chemistry influences not only the results of the etch process ostensibly sidewall damage but also kind and effect of the post etch clean. Each plasma composition results in the necessity of a customized post etch cleaning solution. Finally a k-restore process using Hexamethyldisilazane (HMDS) as restore chemical was demonstrated successfully. Enhanced temperatures and an additional UV-treatment are possibilities to promote the restore effect.

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 helpful. New requirements in MEMS technologies demand optimized processes in metallization for the fabrication of microstructures.

This paper presents some metallization applications and related technology development in the field of MEMS.

The paper describes a low temperature bond process based on an oxygen plasma pretreatment followed by 200°C and 400°C annealing which was to be integrated in our technological process flow to produce micromechanical devices in bulk and surface micromachining like acceleration sensors, gyroscopes and mirror arrays [1]. The results of infrared transmission and the measured bond strengths of the prepared test wafers will be presented in dependence on various pre-treatments and annealing times as well as temperatures. First die separation tests as well as additional detailed investigations showed that the bonding process has the potential to replace an anodic bonding process. During the development of the low temperature bond process it was shown that it is possible to reach a bond strength between 1.5 J/m2 and 2.8 J/m2 depending on the annealing conditions. To optimize the necessary size of the bond frame and to quantify the bond strength limits of the process a test pattern was designed with different arrangements of sensor structures like bond frames, spaces and chevron notch structures. The investigation showed the achieved bond yield in dependence on different sensor structures and bond conditions.

Siliconoxynitride layers with thicknesses between 5 and 10 nm were grown on (100) oriented silicon by rapid thermal processing (RTP) using either N2O or NH3 as nitridant. In order to study the trapping behaviour at the interface and in the insulator bulk, capacitance-voltage (CV) and current-voltage (IV) measurements have been performed combined with different magnitudes of Fowler-Nordheim stress. In addition, Deep Level Transient Spectroscopy (DLTS) has been applied for interface state detection. Auger Electron Spectroscopy (AES) has been used to obtain depth profiles for Si, N, O and C. The deconvolution of the AES signal displays significant peak contributions related to intermedium oxidation states. Nuclear Reaction Analysis (NRA) was successfully applied for hydrogen detection in buried SiOxNy thin films.