• Title/Summary/Keyword: H-bonding

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pH Sensing Properties of ISFETs with LPCVD Silicon Nitride Sensitive-Gate

  • Shin, Paik-Kyun;Thomas Mikolajick;Heiner Ryssel
    • Journal of Electrical Engineering and information Science
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    • v.2 no.3
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    • pp.82-87
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    • 1997

  • Ion-Sensitive Field-Effect Transistors(ISFETs) with LPCVD silicon nitride as a sensitive gate were fabricated on the basis of a CMOS process. The silicon nitride was deposited directly on a poly silicon gate-electrode. Using a specially designed measuring cell, the hydrogen ions sensing properties of the ISFET in liquid could be investigated without any bonding or encapsulation. At first, th sensitivity was estimated by simualtions according to the site-binding theory and the experimental results were analysed and compared with simulated results. The measured dta were in good agreement with the simulated results. The silicon nitride based ISFET has good linearity evaluated from correlation factor ($\geq$0.9998) and a mean pH-sensitivity of 56.8mV/pH. The maximum hysteresis width between forward(pH=3\longrightarrowpH=11)- and backward(pH=11\longrightarrowpH=3) titration was 16.7mV at pH=6.54.

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The Effects of CF4 Partial Pressure on the Hydrophobic Thin Film Formation on Carbon Steel by Surface Treatment and Coating Method with Linear Microwave Ar/CH4/CF4 Plasma

  • Han, Moon-Ki;Cha, Ju-Hong;Lee, Ho-Jun;Chang, Cheol Jong;Jeon, Chang Yeop
    • Journal of Electrical Engineering and Technology
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    • v.12 no.5
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    • pp.2007-2013
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    • 2017

  • In order to give hydrophobic surface properties on carbon steel, the fluorinated amorphous carbon films were prepared by using linear 2.45GHz microwave PECVD device. Two different process approaches have been tested. One is direct deposition of a-C:H:F films using admixture of $Ar/CH_4/CF_4$ working gases and the other is surface treatment using $CF_4$ plasma after deposition of a-C:H film with $Ar/CH_4$ binary gas system. $Ar/CF_4$ plasma treated surface with high $CF_4$ gas ratio shows best hydrophobicity and durability of hydrophobicity. Nanometer scale surface roughness seems one of the most important factors for hydrophobicity within our experimental conditions. The properties of a-C:H:F films and $CF_4$ plasma treated a-C:H films were investigated in terms of surface roughness, hardness, microstructure, chemical bonding, atomic bonding structure between carbon and fluorine, adhesion and water contact angle by using atomic force microscopy (AFM), nano-indentation, Raman analysis and X-ray photoelectron spectroscopy (XPS).

  • https://doi.org/10.5370/JEET.2017.12.5.2007 인용 PDF KSCI