The Sensing Interface Sample Clauses

The Sensing Interface. ‌ Another aspect that deserves some thought when designing a sensor structure is the surface passivation material which acts as a gate dielectric. The SiNW-dielectric interface is important for the electrical stability of the device. SiO2 is not the best pH selective material as it does not provide a stable contact between the liquid and the sensor [1]. Since protons can penetrate the Si-oxide layers leading to large leakage current, different dielectrics (i.e.: Alumina) have been deposited in order to efficiently suppress this issue [10]. The protection layer should be as thin as possible in order to maintain the sensitivity of the device. It has been found in literature that the passivation of the silicon surface via strong covalent Si-C bonds can provide well defined and stable monolayers with insulating properties superior to that of native oxide [25, 26]. Two different dielectric materials have been investigated in this study. First, the dielectric constant εr = 1.7 of the organic monolayer SiC16H33 passivating an oxide free silicon surface as determined by Faber et al.,[25] and thickness td = 1.78 nm were utilized in the simulation. This mimics the functionalization scheme to be employed in future