This title appears in the Scientific Report :
2013
Please use the identifier:
http://hdl.handle.net/2128/5490 in citations.
Noise and Transport Characteristics of Silicon Nanowire Field Effect Transistors with Liquid Gate.
Noise and Transport Characteristics of Silicon Nanowire Field Effect Transistors with Liquid Gate.
Silicon nanowire field effect transistors (Si NW FETs) are promising structures for the development of new biosensors due to their ability to directly translate interactions with target molecules into readable signals. These structures are highly sensitive and selective and are capable of real-time...
Saved in:
Personal Name(s): | Pud, S. (Corresponding author) |
---|---|
Li, Jing / Sibiliev, V. / Acevedo, A. / Petrychuk, M. / Offenhaeusser, A. / Vitusevich, Svetlana | |
Contributing Institute: |
Bioelektronik; ICS-8 JARA-FIT; JARA-FIT Bioelektronik; PGI-8 |
Imprint: |
2013
|
Conference: | The 22-th.Int.Conf. on Noise and Fluctuations (ICNF 2013), Montpellier (France), 2013-06-24 - 2013-06-28 |
Document Type: |
Abstract |
Research Program: |
Physics of the Cell Sensorics and bioinspired systems |
Link: |
OpenAccess |
Publikationsportal JuSER |
Silicon nanowire field effect transistors (Si NW FETs) are promising structures for the development of new biosensors due to their ability to directly translate interactions with target molecules into readable signals. These structures are highly sensitive and selective and are capable of real-time response and label-free detection. However, there are challenges: the stability and reproducibility of the operation of such sensors in a liquid environment due to the property changes of the thin gate dielectric when exposed to an electrolyte for a long time. In this contribution, noise spectroscopy was employed to characterize the performance of the devices in the electrolyte and without it. Noise spectra were measured and analyzed for Si NW FETs with a width of 500nm and a variety of lengths (2-16µm) and a thin SiO2 passivation layer (10nm thickness) in air and phosphate-buffered saline (PBS) at different back-gate voltages, VG. Figure 1 shows the normalized current noise spectral density (NCNSD), SI / I2, at sub-threshold and above-threshold voltages measured in air and PBS. In the sub-threshold region, NCNSD in the device decreased when PBS was introduced to the sample. This decrease can be mainly explained by the changing of the surface charge state in the sample’s top dielectric due to PBS electrolyte adsorption and screening effect as well as only partial contribution of the increased sub-threshold current. Above the threshold voltage, submerging the sample in PBS results in a small increase in the amount of fluctuations in the sample. The lower value of the current at VG-VTh = 1.0 V in PBS only partially influences the normalized noise level behavior. Our results show that exposing the nanowire samples to PBS not only affects the number of charge carriers, but also most likely results in a change in the mobility of charge carriers. |