Abstract
Silicon nitride films have been deposited by the process of mercury-sensitized photochemical vapor deposition (photo-CVD), using a gaseous mixture of SiH 4 and NH 3 under 253.7 nm UV light irradiation. The main advantages of this technique are low deposition temperature (200–400 ° C) and no radition damage. The optimal conditions of the deposit are defined in order to obtain a stable sensor with a surface sensitive to pH: optimal temperature of 200 °C, gas flow rate (SiH 4/NH 3) of 1/80 and deposition time of 8 min. An annealing is necessary at 400 °C in N 2 atmosphere for 20 s. Under these conditions, a deposition thickness f 560 Å and refractive index of 1.97 were obtained. The silicon nitride ISFET obtained has a quasi-nernstian pH response with a sensitivity equal to 53.5±0.5 mV pH −1, due tothe NH 2 sites at the surface of the silicon nitride deposit. The stability of the response when the silicon nitride surface is kept in contact with an aqueous solution is about five months.
Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
