Study on Extended Gate Field Effect Transistor with Nano-TiO-2 Sensing Membrane by Sol-Gel Method

The nano-titanium dioxide (nano-TiO_2) sensing membrane,fabricated by sol-gel technology,was used as the pH-sensing layer of the extended gate field effect transistor (EGFET) device.The objective of this research is the preparation of titanium dioxide materials by sol-gel method using Ti(OBu)_4 as the precursor.In this study,we fabricated a nano-titanium dioxide sensing layer on the ITO glass by dip coating.In order to examine the sensitivity of the nano-TiO_2 films applied to the EGFET devices,we adopted the ITO glass as substrate,and measured theⅠ_(DS)-Ⅴ_G curves of the nano-titanium dioxide separative structure EGFET device in the pH buffer solutions that have different pH values by the Keithley 236 Instrument.By the experimental results,we can obtain the pH sensitivities of the EGFET with nano-TiO_2 sensing membrane prepared by sol-gel method,which is 59.86mV/pH from pH 1 to pH 9.

Study on the Carbon Nanotube Separative Structure for the Extended Gate H^+-Ion Sensitive Field Effect Transistor

We use the carbon nanotube (CNT) as the material of the pH sensing layer of the separative structure for the extended gate H^+-ion sensitive field effect transistor (EGFET) device.The CNT paste was prepared with CNT powder,Ag powder,silicagel,the di-n-butyl phthalate and the toluene solvents by appropriate ratio,then immobilized on the silicon substrate to form the carbon nanotube sensing layer.We measured theⅠ_(DS)-Ⅴ_G curves of the carbon nanotube separative structure EGFET device in the different pH buffer solutions by the Keithley 236Ⅰ-Ⅴmeasurement system.According to the experimental results,we can obtain the pH sensitivities of the carbon nanotube separative structure EGFET device,which is 62.54mV/pH from pH1 to pH13.

Study of Non-Ideal Effects for Extended Gate Field Effect Transistor Chlorine Ion Sensing Device

We use the extended gate field effect transistor (EGFET)as the structure of the chlorine ion sensor,and the chlorine ion ionophores (ETH9033 and TDDMAC1)are incorporated into solvent polymeric membrane (PVC/DOS),then the chlorine ion selective membrane is formed on the sensing window,and the fabrication of the EGFET chlorine ion sensing device is completed.The surface potential on the sensing membrane of the EGFET chlorine ion sensing device will be changed in the different chlorine ion concentration solutions,then changes further gate voltage and drain current to detect chlorine ion concentration.We will study non-ideal effects such as temperature,hysteresis and drift effects for the EGFET chlorine ion sensing device in this paper,these researches will help us to improve the sensing characteristics of the EGFET chlorine ion sensing device.

Electric gating of the multichannel conduction in LaAlO_(3)/SrTiO_(3) superlattices

The electric gating on the transport properties of two-dimensional electron gas(2DEG) at the interface of LaAlO_(3)/SrTiO_(3)(LAO/STO) heterostructure has attracted great research interest due to its potential application in fieldeffect devices. Most of previous works of gate effect were focused on the LAO/STO heterostructure containing only one conductive interface. Here, we systematically investigated the gate effect on high-quality LAO/STO superlattices(SLs)fabricated on the TiO_(2)-terminated(001) STO substrates. In addition to the good metallicity of all SLs, we found that there are two types of charge carriers, the majority carriers and the minority carriers, coexisting in the SLs. The sheet resistance of the SLs with a fixed thickness of the LAO layer increases monotonically as the thickness of the STO layer increases. This is derived from the dependence of the minority carrier density on the thickness of STO. Unlike the LAO/STO heterostructure in which minority and majority carriers are simultaneously modulated by the gate effect, the minority carriers in the SLs can be tuned more significantly by the electric gating while the density of majority carriers is almost invariable. Thus, we consider that the minority carriers may mainly exist in the first interface near the STO substrate that is more sensitive to the back-gate voltage, and the majority carriers exist in the post-deposited STO layers. The SL structure provides the space separation for the multichannel conduction in the 2 DEG, which opens an avenue for the design of field-effect devices based on LAO/STO heterostructure.

Study on the Drift Effect of Potassium Ion Sensing Based on the Extended Gate Field Effect Transistor

The advantages of the extended gate field effect transistor (EGFET) compared with the ion sensitive field effect transistor (ISFET) are easy package,easy preservation,insensitive light effect,and better stability.Although EGFET has above advantages,there are still some non-ideal effects such as drift etc..The drift behavior exists during the measurement process and results in the variation of the output voltage with time.We can obtain the drift value by immersing EGFET into the pH solution for 12 hours and measure the rate of the output voltage versus time after S hours.This study analyzes the sensitivity, stability,and drift effect of the EGFET based on the structure of the ruthenium oxide/silicon (RuO_x/Si) wafer for measuring the potassium ion.The fabrication of the potassium ion sensor can be widely employed in medical detection.

Fabrication of the Sodium Ions Extended Gate Field Effect Transistor by Using the Entrapment Method

The sodium ion is necessary in physiological function and an important element in blood of human body,because the concentration of the sodium ion in the blood directly affects the functions of some organs or pathological feature,how to detect it is an important affair.In this paper,we measure the concentration of sodium ions by the extended gate field effect transistor (EGFET).We use three different substrates RuO_x/p-Si,ITO glass,SnO_2/ITO to fabricate EGFET,and we choose the optimum structure.The fabrication of device needed to use the entrapment method.

Oxygen Scavenging Effect of LaLuO_3/TiN Gate Stack in High-Mobility Si/SiGe/SOI Quantum-Well Transistors

Higher-s dielectric LaLuO3, deposited by molecular beam deposition, with TiN as gate stack is integrated into high-mobility Si/SiGe/SOI quantum-well p-type metal-oxide-semiconduetor field effect transistors. Threshold voltage shift and capacitance equivalent thickness shrink are observed, resulting from oxygen scavenging effect in LaLuO3 with ti-rich TiN after high temperature annealing. The mechanism of oxygen scavenging and its potential for resistive memory applications are analyzed and discussed.

Calibration of the Circuit Measurement for the Glucose Sensor

The extended gate field effect transistor (EGFET)has many advantages such as the fabrication is easy,low cost, easy to operate etc.The EGFET was applied to biosensor in recent years.In this study,the tin oxide (SnO_2)pH sensitive membrane was deposited on ITO glass,when the surface voltage which pH membrane changes,the gate voltage and current channel of MOSFET will change immediately to detect concentration of the glucose sensor.In this study we have devoted to research about the calibration of the circuit measurement for the glucose sensor,and study the calibration system of the drift and hysteresis.

Effect of phosphorus ion implantation on back gate effect of partially depleted SOI NMOS under total dose radiation

The mechanism of improving the TID radiation hardened ability of partially depleted silicon-oninsulator（SOI） devices by using the back-gate phosphorus ion implantation technology is studied. The electron traps introduced in Si O2 near back Si O2/Si interface by phosphorus ions implantation can offset positive trapped charges near the back-gate interface. The implanted high concentration phosphorus ions can greatly reduce the back-gate effect of a partially depleted SOI NMOS device, and anti-total-dose radiation ability can reach the level of 1 Mrad（Si） for experimental devices.

Effect of gate engineering in submicron GaAs MESFET for microwave frequency applications

We present an approach of GaAs MESFET incorporating the gate engineering effect to improve immunity against the short channel effects in order to enhance the scaling capability and the device performance for microwave frequency applications. In this context, a physics-based model for I–V characteristics and various microwave characteristics such as transconductance, cut-off frequency and maximum frequency of oscillation of submicron triple material gate（TM） GaAs MESFET are developed. The reduced short channel effects have also been discussed in combined designs i.e. TM, DM and SM in order to show the impact of our approach on the GaAs MESFETs-based device design. The proposed analytical models have been verified by their good agreement with 2D numerical simulations. The models developed in this paper will be useful for submicron and microwave analysis for circuit design.

A gated strategy stabilizes room-temperature phosphorescence

Room-temperature phosphorescence(RTP)of purely organic materials is easily quenched with unexpected purposes because the excited triplet state is extremely susceptible to external stimuli.How to stabilize the RTP property of purely organic luminogens is still challenging and considered as the bottleneck in the further advancement of the bottom-up approach.Here,we describe a gated strategy that can effectively harness RTP by employing complexation/dissociation with proton.Due to the order-disorder transition orientation of intermolecular packing,the RTP of organic molecules 2,4,6-tris(4′-bromo-[1,1′-biphenyl]-4-yl)-1,3,5-triazine(Br-TRZ)will easily vanish upon mechanical force.Impressively,by enhancing its intramolec-ular charge transfer effect,the protonated Br-TRZ stubbornly possesses an obvious RTP under external grinding,whatever in the ordered or disordered intermolec-ular arrangement state.Consequently,the“Lock”gate of RTP was achieved in the protonated Br-TRZ molecule.Combined with theoretical calculation analy-sis,the enhanced charge transfer effect can narrow the energy gap singlet-tripletsignificantly,and stabilize the RTP property of triazine derivative sequentially.Fur-thermore,the locked RTP can be tuned via proton and counterions repeatedly and show excellent reversibility.This gated RTP concept provides an effective strategy for stabilizing the RTP emission of purely organic systems.

Nanoscale Ⅲ-Ⅴ on Si-based junctionless tunnel transistor for EHF band applications

A single gate Ⅲ-Ⅴ junctionless tunnel field effect transistor（SG-JLTFET） has been reported which shows excellent dc characteristics at low power supply operation.This device has a thin uniformly n-type doped channel of GaSb i.e.gallium antimonide which is grown epitaxially over silicon substrate.The DC performance parameters such as I（on）,I（on）/I（off）,average and point subthreshold slope as well as device parameters for analog applications viz.transconductance gm,transconductance generation efficiency gm/ID,various capacitances and the unity gain frequency fT are studied using a device simulator.Along with examining its endurance to short channel effects,the performances are also compared with a Silicon Dual Gate Junctionless Tunnel FET（DG-JLTFET）.The DC and small signal analog performance reflects that GaSb SG-JLTFET has immense purview for extreme high-frequency and low-power applications.

Impact of the lateral width of the gate recess on the DC and RF characteristics of InAlAs/InGaAs HEMTs

We fabricated 88 nm gate-length InP-based InAlAs/InGaAs high electron mobility transistors（HEMTs） with a current gain cutoff frequency of 100 GHz and a maximum oscillation frequency of 185 GHz.The characteristics of HEMTs with side-etched region lengths（L_（Side）） of 300,412 and 1070 nm were analyzed.With the increase in L_（Side）,the kink effect became notable in the DC characteristics,which resulted from the surface state and the effect of impact ionization.The kink effect was qualitatively explained through energy band diagrams,and then eased off by reducing the L_（Side）.Meanwhile,the L_（Side） dependence of the radio frequency characteristics,which were influenced by the parasitic capacitance,as well as the parasitic resistance of the source and drain,was studied.This work will be of great importance in fabricating high-performance InP HEMTs.

Performance analysis of InSb based QWFET for ultra high speed applications

An indium antimonide based QWFET（quantum well field effect transistor） with the gate length down to 50 nm has been designed and investigated for the first time for L-band radar applications at 230 GHz. QWFETs are designed at the high performance node of the International Technology Road Map for Semiconductors（ITRS）requirements of drive current（Semiconductor Industry Association 2010）. The performance of the device is investigated using the SYNOPSYS CAD（TCAD） software. In Sb based QWFET could be a promising device technology for very low power and ultra-high speed performance with 5–10 times low DC power dissipation.

Analysis of DC and analog/RF performance on Cyl-GAA-TFET using distinct device geometry

In this paper, analysis of DC and analog/RF performance on cylindrical gate-all-around tunnel fieldeffect transistor（TFET） has been made using distinct device geometry. Firstly, performance parameters of GAATFET are analyzed in terms of drain current, gate capacitances, transconductance, source-drain conductance at different radii and channel length. Furthermore, we also produce the geometrical analysis towards the optimized investigation of radio frequency parameters like cut-off frequency, maximum oscillation frequency and gain bandwidth product using a 3D technology computer-aided design ATLAS. Due to band-to-band tunneling based current mechanism unlike MOSFET, gate-bias dependence values as primary parameters of TFET differ. We also analyze that the maximum current occurs when radii of Si is around 8 nm due to high gate controllability over channel with reduced fringing effects and also there is no change in the current of TFET on varying its length from 100 to 40 nm.However current starts to increase when channel length is further reduced for 40 to 30 nm. Both of these trades-offs affect the RF performance of the device.