Quantitative studies of long-term stable, top-down fabricated silicon nanowire pH sensors
We report a simple and effective method to develop long-term stable, top-down fabricated silicon nanowire (SiNW) pH sensors along with systematic studies on the performance of the sensors. In this work, we fabricated the SiNW pH sensors based on top-down fabrication processes. In order to improve the stability of the sensor performance, the sensors were coated with a passivation layer (PECVD-based silicon nitride) for effective electrical insulation and ion-blocking. The stability, pH sensitivity, and repeatability of the sensor response are critically analyzed with regard to the physics of sensing interface between sample liquid and the sensor surface. Also, trade-off between the stability and pH sensitivity of the sensor response is discussed.
KeywordsPDMS Silicon Nitride Passivation Layer Plasma Enhance Chemical Vapor Deposition Silicon Nitride Film
This research is supported by the U.S. Department of Energy (DOE, Grant #: DE-AC02-05CH112), a grant (2009K000069) from the Center for Nanoscale Mechatronics & Manufacturing (CNMM), one of the 21st Century Frontier Research Programs, and Basic Science Research Program (Grant #: 2011-0004409), which are supported by Ministry of Education, Science and Technology, Korea. S. Choi thanks for his graduate fellowship from the Samsung Scholarship Foundation.
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