In etch plasmas used for semiconductor processing, concentrations of the precursor gas NF 3 and of the etch product SiF 4 are measured online and in situ using a new diagnostic arrangement, the Q-MACS Etch system, which is based on quantum cascade laser absorption spectroscopy (QCLAS). In addition, the etch rates of SiO 2 layers and of the silicon wafer are monitored including plasma-etching endpoint detection. For this purpose the Q-MACS Etch system is working as an interferometer arrangement. The experiments are performed in an industrial, dual-frequency, capacitively coupled, magnetically enhanced, reactive ion etcher (MERIE), which is a plasma reactor developed for dynamic random access memory (DRAM) technologies. In the spectral range 1028 ± 0.3 cm -1 , the absorption cross-sections of SiF 4 and NF 3 are determined to be r = (7.7 ± 0.7) × 10 -18 cm 2 molecule -1 and r = (8.7 ± 0.8) × 10 -20 cm 2 molecule -1 , respectively.

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In this paper, first measurements with a particularly designed quantum-cascade-laser (QCL) arrangement for application in semiconductor industrial environments for in situ wafer-to-wafer etch monitoring are reported. The combination of QCLs and infrared absorption spectroscopy (QCLAS) opens up new possibilities for plasma process monitoring and control. In silicon etch plasmas, concentrations of the etch product SiF 4 were measured real time in an industrial-production environment. The comparison of the results with inline data of the processed wafers shows a correlation between the amount of produced SiF 4 and the measures of the trench depth and the bottom void. Furthermore, it is shown that the characteristics of the refractive index of Si and SiO 2 in the mid-infrared can be used to determine etch rates of SiO 2 and Si wafers during the processing.

In the last decades, polymer brush coatings have proven to be excellent anti-fouling materials by preventing protein adhesion. When using this property to restrict cell growth laterally in cell culture, it is crucial to ensure that other cell functions remain unaffected. The present study therefore examines MC3T3-E1 cell growth and morphology on patterned PSBMA brush substrates and probes their proliferation potential at mRNA level. The osteoblastic cells display a more elongated morphology than cells on the control substrates, but show no sign of elevated levels of the apoptosis marker p53 or diminished levels of Ki-67 or H4, which serve as indicators of proliferation. Therefore, patterned polymer brushes do not seem to influence cells in their proliferation state and are suitable cell culture substrates. Nevertheless, the use of polymer brush surfaces in long-term cell culture was found to be limited by their instability in cell culture medium.

Implant medical research and tissue engineering both target the design of novel biomaterials for the improvement of human health and clinical applications. In order to develop improved surface coatings for hard tissue (bone) replacement materials and implant devices, we are developing micropatterned coatings consisting of polymer brushes. These are used as organic templates for the mineralization of calcium phosphate in order to improve adhesion of bone cells. First, we give a short account of the current state-of-the-art in this particular field of biomaterial development, while in the second part the preliminary results of cell culture experiments are presented, in which the biocompatibility of polymer brushes are tested on human mesenchymal stem cells.