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This study reports use of inexpensive intensity-based plastic optical fiber (POF) in the form of cantilever beam to monitor the force. The cantilever consists of POF surface bonded on the surface of metal beams viz. spring steel (SS) and mild steel (MS) and subjected to force. The performance of the force sensor is evaluated during macro-bending caused because of the deflection of the beam by applied force. Experimentally obtained detector output of POF, which could be measured with negligible hysteresis is compared with finite element analysis in the range between 0.0098 and 19.613 N. The reproducibility of the sensor is observed in the limit of ±1%. The proposed sensor can replace stain gauge load cell to certain extent in some applications. © 2009 Wiley Periodicals, Inc. Microwave Opt Technol Lett 51: 1020–1023, 2009; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.24217

The present study reports the use of an intensity based plastic optical fiber (POF) as a force sensor. Different materials for beam, such as spring steel and mild steel, are used to evaluate the performance of the force sensor during macro-bending. The POF is surface bonded to a beam and subjected to force. The system relies on monitoring the light intensity, as the POF is subjected to transversal loading conditions. Experimentally obtained output of POF which could be measured with negligible hysteresis is compared with finite element analysis in the range between 0.0098 N to 19.613 N. The reproducibility of the sensor is observed in the limit of ±1%. The finding of this study highlights the potential use of POF sensors for various force sensing applications.

Titanium nitride particles formed in thermal and plasma-enhanced metallorganic chemical vapor deposition processes using tetrakis(diethylamino)titanium were investigated. Particle formation was studied by using a particle beam mass spectrometer calibrated by a certificate reference material (NaCl) as a function of process variables such as bubbler temperature, deposition temperature and pressure, sampling positions in the reactor, plasma conditions, and a flow rate of carrier gas. From these results, the effects of the sampling position and the thermal and plasma energies were studied. These measured results were in reasonable agreement with the transmission electron microscopy results.

We investigated characteristics of contaminant particles generated in titanium nitride (TiN) metal organic chemical vapor deposition (MOCVD) using tetrakis(dimethyl-amino-titanium) (TDMAT) as a precursor. Variation of the particle distribution generated before and after decomposition of TDMAT was estimated with the modified particle beam mass spectrometer (PBMS) in real-time. Particle size and concentration were sensitive to the change of the chemical status of TDMAT. When integrated absorbance of CH3 stretching features was increased, Particle size and concentration were bigger and higher, respectively. The degree of thermal decomposition of TMDAT was verified with in-situ Fourier transform infrared (FT-IR) spectroscopy and the morphology of films was measured by atomic force microscopy (AFM).

This study proposes a method for monitoring the decomposition state of a metal organic precursor which is used for the metal organic chemical vapor deposition (MOCVD) system. As many kinds of precursors for MOCVD such as tetrakis(dimethylamido)titanium (TDMAT) are highly likely to decompose due to the instability of their chemical structure during processing, critical problems are generated for thin film formation and its yield in this case. Although real-time monitoring technology on the decomposition degree of these precursors is essential for metallization, metal gate or electrode processes for memory devices, both commercialized technology and fundamental research have scarcely been accomplished. Therefore, this study endeavors for acknowledgment by the semiconductor industry with a proposal for a real-time monitoring method on the decomposition degree of the precursor through an ultrasonic diagnosis method. However, it is difficult to perform a degradation mechanism analysis since measuring the viscosity and physical properties of TDMAT is complicated due to its sensitivity to air. Therefore, viscosity was measured using a Pd compound (tetrakis(triphenylphosphine)palladium(0), Pd(PPh3)4) which is stable in air and has a similar chemical structure to TDMAT.