METAL OXIDE THIN FILMS AS PH SENSING MEMBRANE FOR EXTENDED GATE FIELD EFFECT TRANSISTOR

2016 ◽  
Vol 78 (5-8) ◽  
Author(s):  
Muhammad AlHadi Zulkefle ◽  
Rohanieza Abdul Rahman ◽  
Khairul Aimi Yusof ◽  
Wan Fazlida Hanim Abdullah ◽  
Mohamad Rusop Mahmood ◽  
...  
Keyword(s):  
Thin Film ◽  
Thin Films ◽  
Field Effect ◽  
Field Effect Transistor ◽  
Sol Gel ◽  
Ph Sensing ◽  
Tio2 Thin Films ◽  
Suitable Material ◽  
Effect Transistor ◽  
Sensing Membrane

In this research, metal oxides (ZnO and TiO2) thin films were fabricated by the sol-gel spin coating method. The thin films were applied as the pH sensing membrane for the extended-gate field effect transistor (EGFET) sensor to distinguish the sensing capability between them. The surface morphology, thin film components and crystalline quality were characterized and the sensor performance of both materials were characterized and compared. The results showed that TiO2 thin film gave higher sensitivity with better linearity compared to the ZnO thin films hence was considered a more suitable material to be used as sensing membrane in EGFET pH sensor compared to zinc oxide. 

scholarly journals Spin Speed and Duration Dependence of TiO2Thin Films pH Sensing Behavior

2016 ◽  
Vol 2016 ◽  
pp. 1-8 ◽  
Author(s):  
Muhammad AlHadi Zulkefle ◽  
Rohanieza Abdul Rahman ◽  
Khairul Aimi Yusof ◽  
Wan Fazlida Hanim Abdullah ◽  
Mohamad Rusop ◽  
...  
Keyword(s):  
Thin Films ◽  
Field Effect ◽  
Field Effect Transistor ◽  
Ph Sensor ◽  
Oxide Semiconductor ◽  
Ph Sensing ◽  
Spin Speed ◽  
Coating Method ◽  
Effect Transistor ◽  
Sensing Membrane

Titanium dioxide (TiO2) thin films were applied as the sensing membrane of an extended-gate field-effect transistor (EGFET) pH sensor. TiO2thin films were deposited by spin coating method and the influences of the spin speed and spin duration on the pH sensing behavior of TiO2thin films were investigated. The spin coated TiO2thin films were connected to commercial metal-oxide-semiconductor field-effect transistor (MOSFET) to form the extended gates and the MOSFET was integrated in a readout interfacing circuit to complete the EGFET pH sensor system. For the spin speed parameter investigation, the highest sensitivity was obtained for the sample spun at 3000 rpm at a fixed spinning time of 60 s, which was 60.3 mV/pH. The sensitivity was further improved to achieve 68 mV/pH with good linearity of 0.9943 when the spin time was 75 s at the speed of 3000 rpm.

scholarly journals EVALUATION ON THE EGFET PH SENSING PERFORMANCE OF SOL-GEL SPIN COATED TITANIUM DIOXIDE THIN FILM

2021 ◽  
Vol 83 (4) ◽  
pp. 119-125
Author(s):  
Muhammad AlHadi Zulkefle ◽  
Sukreen Hana Herman ◽  
Rohanieza Abdul Rahman ◽  
Khairul Aimi Yusof ◽  
Aimi Bazilah Rosli ◽  
...  
Keyword(s):  
Thin Film ◽  
Tio2 Thin Film ◽  
Drift Rate ◽  
Sol Gel ◽  
Ph Sensor ◽  
Ph Sensing ◽  
Coating Method ◽  
Effect Transistor ◽  
Sensing Membrane ◽  
Sensing Performance

For this study, TiO2 thin film was fabricated using the sol-gel spin coating method. The fabricated film was then applied as a sensing membrane in an extended gate field effect transistor (EGFET) pH sensor system. The pH sensing performance of the sol-gel spin-coated TiO2 was evaluated in terms of sensitivity, linearity, and hysteresis where the value obtained was 58.70 mV/pH, 0.9922, and 86.17 mV respectively. The drift rate of the sample when being measured for 12 consecutive hours was also determined where measurement in pH 4, pH 7, and pH 10 yield drift rate of 1.72 mV/h, 4.14 mV/h, and 6.05 mV/h respectively.  Besides that, the TiO2 was characterized for its thickness (24.32 nm) and surface roughness (5.129 nm). From the results obtained, it was found that sol-gel spin-coated TiO2 thin film with thickness between 20 - 29 nm will have high pH sensitivity (more than 50 mV/pH).

scholarly journals Deposition of High-k Samarium Oxide Membrane on Polysilicon for the Extented-Gate Field-Effect Transistor (EGFET) Applications

2014 ◽  
Vol 17 (1) ◽  
pp. 013-016
Author(s):  
Chyuan-Haur Kao ◽  
Hsiang Chen ◽  
Jer-Chyi Wang ◽  
Yu-Cheng Chu ◽  
Chiao-Sung Lai ◽  
...  
Keyword(s):  
Field Effect ◽  
Field Effect Transistor ◽  
High Sensitivity ◽  
Great Promise ◽  
Ph Sensing ◽  
Samarium Oxide ◽  
High K ◽  
Effect Transistor ◽  
Oxide Membrane ◽  
Sensing Membrane

The paper reports samarium oxide as pH. sensing membrane on polysilicon combined with proper post deposition annealing for the extended-gate field-effect transistor (EGFET) application at the first time. It can be found that the high-k samarium oxide membrane annealed at 700 ºC could obtain high sensitivity, high linearity, low hysteresis voltage, and low drift rate due to improvements ofcrystalline structures. The high-k Sm2O3 sensing membrane shows great promise for future bio-medical device applications.

scholarly journals Integrating Epitaxial-Like Pb(Zr,Ti)O3 Thin-Film into Silicon for Next-Generation Ferroelectric Field-Effect Transistor

2016 ◽  
Vol 6 (1) ◽  
Author(s):  
Jae Hyo Park ◽  
Hyung Yoon Kim ◽  
Gil Su Jang ◽  
Ki Hwan Seok ◽  
Hee Jae Chae ◽  
...  
Keyword(s):  
Thin Film ◽  
Thin Films ◽  
Grain Boundaries ◽  
Field Effect ◽  
Field Effect Transistor ◽  
Ferroelectric Thin Film ◽  
Atomic Layer ◽  
Nucleation And Growth ◽  
Test Results ◽  
Effect Transistor

Abstract The development of ferroelectric random-access memory (FeRAM) technology with control of grain boundaries would result in a breakthrough for new nonvolatile memory devices. The excellent piezoelectric and electrical properties of bulk ferroelectrics are degraded when the ferroelectric is processed into thin films because the grain boundaries then form randomly. Controlling the nature of nucleation and growth are the keys to achieving a good crystalline thin-film. However, the sought after high-quality ferroelectric thin-film has so far been thought to be impossible to make, and research has been restricted to atomic-layer deposition which is extremely expensive and has poor reproducibility. Here we demonstrate a novel epitaxial-like growth technique to achieve extremely uniform and large rectangular-shaped grains in thin-film ferroelectrics by dividing the nucleation and growth phases. With this technique, it is possible to achieve 100-μm large uniform grains, even made available on Si, which is large enough to fabricate a field-effect transistor in each grain. The electrical and reliability test results, including endurance and retention test results, were superior to other FeRAMs reported so far and thus the results presented here constitute the first step toward the development of FeRAM using epitaxial-like ferroelectric thin-films.

scholarly journals Optimization of electrical conductivity of SnS thin film of 0.2 < t ≤ 0.4 μm thicknes for field effect transistor application

2021 ◽  
Vol 67 (2 Mar-Apr) ◽  
pp. 263
Author(s):  
T. O. Daniel ◽  
U. E. Uno ◽  
K. U. Isah ◽  
U. Ahmadu
Keyword(s):  
Thin Film ◽  
Thin Films ◽  
Electrical Conductivity ◽  
Grain Size ◽  
Grain Boundary ◽  
Film Thickness ◽  
Threshold Voltage ◽  
Field Effect ◽  
Field Effect Transistor ◽  
Effect Transistor

This study is focused on the investigation of SnS thin film for transistor application. Electron trap which is associated with grain boundary effect affects the electrical conductivity of SnS semiconductor thin film thereby militating the attainment of the threshold voltage required for transistor operation. Grain size and grain boundary is a function of a semiconductor’s thickness. SnS semiconductor thin films of 0.20, 0.25, 0.30, 0.35, 0.40 μm were deposited using aerosol assisted chemical vapour deposition on glass substrates. Profilometry, Scanning electron microscope, Energy dispersive X-ray spectroscopy and hall measurement were used to characterise the composition, microstructure and electrical properties of the SnS thin film.  SnS thin films were found to consist of Sn and S elements whose composition varied with increase in thickness. The film conductivity was found to vary with grain size and grain boundary which is a function of the film thickness. The SnS film of 0.4 μm thickness shows optimal grain growth with a grain size of 130.31 nm signifying an optimum for the as deposited SnS films as the larger grains reduces the number of grain boundaries and charge trap density which allows charge carriers to move freely in the lattice thereby causing a reduction in resistivity and increase in conductivity of the films which is essential in obtaining the threshold voltage for a transistor semiconductor channel layer operation. The carrier concentration of due to low resistivity of 3.612 ×105 Ωcm of 0.4 μm SnS thin film thickness is optimum and favours the attainment of the threshold voltage for a field effect transistor operation hence the application of SnS thin film as a semiconductor channel layer in a field effect transistor.

scholarly journals Electrical Characteristics and pH Response of a Parylene-H Sensing Membrane in a Si-Nanonet Ion-Sensitive Field-Effect Transistor

Sensors ◽  
2018 ◽  
Vol 18 (11) ◽  
pp. 3892 ◽  
Author(s):  
Bo Jin ◽  
Ga-Yeon Lee ◽  
ChanOh Park ◽  
Donghoon Kim ◽  
Wonyeong Choi ◽  
...  
Keyword(s):  
Field Effect ◽  
Field Effect Transistor ◽  
Ph Value ◽  
Signal To Noise Ratio ◽  
Low Frequency ◽  
Frequency Noise ◽  
Electrical Characteristics ◽  
Ph Sensing ◽  
Effect Transistor ◽  
Sensing Membrane

We report the electrical characteristics and pH responses of a Si-nanonet ion-sensitive field-effect transistor with ultra-thin parylene-H as a gate sensing membrane. The fabricated device shows excellent DC characteristics: a low subthreshold swing of 85 mV/dec, a high current on/off ratio of ~107 and a low gate leakage current of ~10−10 A. The low interface trap density of 1.04 × 1012 cm−2 and high field-effect mobility of 510 cm2V−1s−1 were obtained. The pH responses of the devices were evaluated in various pH buffer solutions. A high pH sensitivity of 48.1 ± 0.5 mV/pH with a device-to-device variation of ~6.1% was achieved. From the low-frequency noise characterization, the signal-to-noise ratio was extracted as high as ~3400 A/A with the lowest noise equivalent pH value of ~0.002 pH. These excellent intrinsic electrical and pH sensing performances suggest that parylene-H can be promising as a sensing membrane in an ISFET-based biosensor platform.

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