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This paper presents an acceleration-threshold sensor fabricated with an electroplating technology which can be integrated on top of a pre-processed CMOS signal processing circuit. The device can be manufactured using a standard low-cost CMOS production line and then adding the mechanical sensor elements via a specialized back-end process. This makes the system especially interesting for automotive applications, such as airbag safety systems or transportation shock monitoring systems, where smaller size, improved functionality, high reliability and low costs are important.

Physical vapor deposition of hexadecafluorophthalocyaninatozinc (F 16 PcZn) is performed under UHV conditions from monolayer coverages to an average thickness of about 20 nm on the (100) surfaces of NaCl, KCl, and KBr and on quartz glass as well as on microstructured interdigitated electrode arrays on amorphous SiO 2 . UV-vis absorption spectroscopy indicates stacks of cofacial parallel molecules for thin films on SiO 2 and NaCl, whereas a component typical for a head-to-tail arrangement of molecules is detected on KCl and KBr. Atomic force microscopy shows well-defined crystals oriented in a defined azimuth angle relative to the substrate lattice on KCl and KBr, indicating a growth in molecular square lattices parallel to the substrate surface which is confirmed by molecular mechanics and periodic surface potential calculations. Plateaus of molecules predominantly standing upright on the surface are seen for the films on NaCl and SiO 2 which is confirmed by the relative intensity of optical absorptions and by the electrical conductivity changes observed during growth on SiO 2 . The temperature dependence of the electrical conductivity of films on SiO 2 yields an increase of the thermal activation energy around 200 °C corresponding to a loss in spectral fine structure as reported earlier [J. Phys. Chem. B 1999, 103, 3078]. A clear correlation is seen between film structure and electrical as well as optical properties of molecular semiconductor thin films.

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