scholarly journals An Extended Gate Field Effect Transistor (EGFET) pH Microsensor

Author(s):  
İpek Avcı ◽  
Merve Oğuz ◽  
Mustafa Şen

Here, an extended – gate field effect transistor (EGFET) pH microsensor was developed for use in fast and sensitive pH measurement applications. The system consisted of two components; a pH sensitive modified gold electrode and a simple and cheap metal oxide semiconductor field-effect transistor (MOSFET). Polypyrrole, a semiconductor and pH responsive polymer, was formed by electropolymerization of pyrrole monomer at the surface of the gold electrode in galvostanic mode. Then, measurements were made in PBS at different pH values using the pH sensitive electrode. In this context, the pH sensitivity of polypyrrole with respect to electropolymerization and incubation time were studied. According to the results, the EGFET pH microsensor formed by 4-min pyrrole electropolymerization showed at pH 6-12 the highest pH sensitivity with 67 mV/pH

2021 ◽  
Author(s):  
İpek Avcı ◽  
Merve Oğuz ◽  
Mustafa Şen

Here, an extended – gate field effect transistor (EGFET) pH microsensor was developed for use in fast and sensitive pH measurement applications. The system consisted of two components; a pH sensitive modified gold electrode and a simple and cheap metal oxide semiconductor field-effect transistor (MOSFET). Polypyrrole, a semiconductor and pH responsive polymer, was formed by electropolymerization of pyrrole monomer at the surface of the gold electrode in galvostanic mode. Then, measurements were made in PBS at different pH values using the pH sensitive electrode. In this context, the pH sensitivity of polypyrrole with respect to electropolymerization and incubation time were studied. According to the results, the EGFET pH microsensor formed by 4-min pyrrole electropolymerization showed at pH 6-12 the highest pH sensitivity with 67 mV/pH


2021 ◽  
Author(s):  
Mustafa ŞEN ◽  
Fikri Seven

Here, an ultra-small size, simple and inexpensive metal oxide semiconductor field effect transistor (MOSFET)-integrated needle type EGFET pH microsensor was fabricated. The EGFET pH mi?crosensor has the potential to be applied to fast and precise local pH measurements. The system was composed of two components; a pH sensitive probe and a MOSFET. The pH sensitive probe wasmade by electrochemically coating the surface of a Pt ultra micro-electrode with polypyrrole, a semi-conductor polymer. The pH sensitive probe was then integrated with the gate of the MOSFET to carry out measurements in PBS at different pH values. The real time response of the EGFET pH microsen?sor was also tested by cycling the probe in three solutions at different pH. The results showed that the developed pH microsensor is sensitive to pH change. It is expected that the EGFET pH microsensor will allow local pH analysis in biological samples or corrosion studies


2021 ◽  
Vol 5 (1) ◽  
Author(s):  
Aryan Afzalian

AbstractUsing accurate dissipative DFT-NEGF atomistic-simulation techniques within the Wannier-Function formalism, we give a fresh look at the possibility of sub-10-nm scaling for high-performance complementary metal oxide semiconductor (CMOS) applications. We show that a combination of good electrostatic control together with high mobility is paramount to meet the stringent roadmap targets. Such requirements typically play against each other at sub-10-nm gate length for MOS transistors made of conventional semiconductor materials like Si, Ge, or III–V and dimensional scaling is expected to end ~12 nm gate-length (pitch of 40 nm). We demonstrate that using alternative 2D channel materials, such as the less-explored HfS2 or ZrS2, high-drive current down to ~6 nm is, however, achievable. We also propose a dynamically doped field-effect transistor concept, that scales better than its MOSFET counterpart. Used in combination with a high-mobility material such as HfS2, it allows for keeping the stringent high-performance CMOS on current and competitive energy-delay performance, when scaling down to virtually 0 nm gate length using a single-gate architecture and an ultra-compact design (pitch of 22 nm). The dynamically doped field-effect transistor further addresses the grand-challenge of doping in ultra-scaled devices and 2D materials in particular.


Materials ◽  
2021 ◽  
Vol 14 (13) ◽  
pp. 3554
Author(s):  
Jaeyeop Na ◽  
Jinhee Cheon ◽  
Kwangsoo Kim

In this paper, a novel 4H-SiC split heterojunction gate double trench metal-oxide-semiconductor field-effect transistor (SHG-DTMOS) is proposed to improve switching speed and loss. The device modifies the split gate double trench MOSFET (SG-DTMOS) by changing the N+ polysilicon split gate to the P+ polysilicon split gate. It has two separate P+ shielding regions under the gate to use the P+ split polysilicon gate as a heterojunction body diode and prevent reverse leakage `current. The static and most dynamic characteristics of the SHG-DTMOS are almost like those of the SG-DTMOS. However, the reverse recovery charge is improved by 65.83% and 73.45%, and the switching loss is improved by 54.84% and 44.98%, respectively, compared with the conventional double trench MOSFET (Con-DTMOS) and SG-DTMOS owing to the heterojunction.


1987 ◽  
Vol 65 (8) ◽  
pp. 995-998
Author(s):  
N. G. Tarr

It is shown that the accuracy of the charge-sheet model for the long-channel metal-oxide-semiconductor field-effect transistor can be improved by allowing for the small potential drop across the inversion layer, and by using a more accurate analytic approximation for the charge stored in the depletion region.


2008 ◽  
Vol 1144 ◽  
Author(s):  
Pranav Garg ◽  
Yi Hong ◽  
Md. Mash-Hud Iqbal ◽  
Stephen J. Fonash

ABSTRACTRecently, we have experimentally demonstrated a very simply structured unipolar accumulation-type metal oxide semiconductor field effect transistor (AMOSFET) using grow-in-place silicon nanowires. The AMOSFET consists of a single doping type nanowire, metal source and drain contacts which are separated by a partially gated region. Despite its simple configuration, it is capable of high performance thereby offering the potential of a low manufacturing-cost transistor. Since the quality of the metal/semiconductor ohmic source and drain contacts impacts AMOSFET performance, we repot here on initial exploration of contact variations and of the impact of thermal process history. With process optimization, current on/off ratios of 106 and subthreshold swings of 70 mV/dec have been achieved with these simple devices


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