Optimization of pH sensing using silicon nanowire field effect transistors with HfO sub(2) as the sensing surface

Silicon nanowire field effect transistor sensors with SiO sub(2)/HfO sub(2) as the gate dielectric sensing surface are fabricated using a top down approach. These sensors are optimized for pH sensing with two key characteristics. First, the pH sensitivity is shown to be independent of buffer concent...

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Bibliographic Details
Published in:Nanotechnology 2011-10, Vol.22 (40), p.405501-1-6
Main Authors: Zafar, S, D'Emic, C, Afzali, A, Fletcher, B, Zhu, Y, Ning, T
Format: Article
Language:English
Subjects:
Detection
Field effect transistors
Hafnium oxide
Nanomaterials
Nanostructure
Nanowires
Sensors
Silicon
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Summary:Silicon nanowire field effect transistor sensors with SiO sub(2)/HfO sub(2) as the gate dielectric sensing surface are fabricated using a top down approach. These sensors are optimized for pH sensing with two key characteristics. First, the pH sensitivity is shown to be independent of buffer concentration. Second, the observed pH sensitivity is enhanced and is equal to the Nernst maximum sensitivity limit of 59 mV/pH with a corresponding subthreshold drain current change of similar to 650%/pH. These two enhanced pH sensing characteristics are attributed to the use of HfO sub(2) as the sensing surface and an optimized fabrication process compatible with silicon processing technology.
ISSN:0957-4484
DOI:10.1088/0957-4484/22/40/405501