International Technology Roadmap for Semiconductors 2003の要求清浄度について － シリコンウエハ表面と雰囲気環境に要求される清浄度, 分析方法の現状について －

This survey deals with 1/f noise in homogeneous semiconductor samples. A distinction is made between mobility noise and number noise. It is shown that there always is mobility noise with an /spl alpha/ value with a magnitude in the order of 10/sup -4/. Damaging the crystal has a strong influence on /spl alpha/, /spl alpha/ may increase by orders of magnitude. Some theoretical models are briefly discussed none of them can explain all experimental results. The /spl alpha/ values of several semiconductors are given. These values can be used in calculations of 1/f noise in devices. >

1/f Noise Sources

Science and Engineering Research Board, India, Department of Science & Technology, Government of India: ECR/2017/000259

Adaptive hybrid intelligent MPPT controller to approximate effectual wind speed and optimal rotor speed of variable speed wind turbine.

This paper compares circular gate (CG) tunnel field effect transistor (TFET) and uniform gate Heterojunction (HJ) TFET as label-free biosensors based on dielectric modulation. Neutral and charged biomolecules with different values of dielectric constant are considered. Sensitivities of partially filled nanogaps arising out of steric hindrance in both the biosensors for concave, convex, increasing and decreasing step profiles of biomolecules are compared. The effect of probe position on sensitivities of the two biosensors is reported for various cases. A status map is presented, plotting the sensitivities of some of the most significant works in applications of FET as label-free biosensors along with sensitivities of the proposed devices. CG TFET exhibits higher sensitivity than HJ TFET due to its non-uniform gate architecture. The sensitivities of the TFETs are highly dependent on the position of biomolecules (steric hindrance and probe position) with respect to the tunnel junction. A maximum sensitivity of $1.31\times 10^{8}$ ( $3.382\times 10^{6}$ ) is achieved for fully filled nanogap in CG TFET (HJ TFET) for dielectric constant 12.

Comparative Analyses of Circular Gate TFET and Heterojunction TFET for Dielectric-Modulated Label-Free Biosensing

In this letter, we report that the source and channel Fermi-Dirac distributions in interband-tunneling-controlled transistors play a fundamental role on the modulation of the injected current. We explain the superlinear onset of the output characteristics based on the occupancy function modulation. Thus, we point out that, along with the tunneling barrier transparency, the availability of carriers and empty states, at the beginning and at the end of the tunneling path, respectively, should be always taken into account for a proper modeling of tunnel FETs.

Understanding the Superlinear Onset of Tunnel-FET Output Characteristic

A comprehensive evaluation of sensitivity between double gate tunnel FET and n+ pocket doped vertical tunnel FET based label-free biosensors is reported in this work. Both the biosensors possess nanogaps on the left and right of the fixed dielectric (HfO2) which enhances the capture area of the biosensors. Comparison has been made on the TCAD simulation studies of their sensitivities considering neutral/charged biomolecules having different dielectric constants. The sensitivity of VB is found to be approximately 104 times the sensitivity of DB due to its current conduction in both vertical and lateral directions. Also, the effects of steric hindrance and irregular position of probes/receptors are analyzed to understand the non-ideal behavior of the sensors. Sensitivity is calculated from the simulated results for four different cases of partially filled nanogaps – decreasing, increasing, concave and convex profiles. It rises by about 5–7% when filled factor is increased from 40 to 66%. Finally, benchmarking of proposed VB is done against other published literature as it gives better result in terms of sensitivity.

N+ Pocket Doped Vertical TFET Based Dielectric-Modulated Biosensor Considering Non-Ideal Hybridization Issue: A Simulation Study

We systemically investigated the impact of variation in temperature on electrical parameters for a dual material gate (DMG) FinFET. We have highlighted the DC performance such as drain current characteristics, subthreshold swing (SS), and Ion/Ioff for the variation in temperature from 200 to 350 K. Furthermore, the influence of temperature on RF/Analog parameters like transconductance (gm), output conductance (gd), gate capacitance (CGG), intrinsic delay, transconductance generation factor (TGF = gm/ID), intrinsic gain (gm/gd), cutoff frequency (ft), gain frequency product (GFP), transconductance frequency product (TFP), and gain transconductance frequency product (GTFP) are presented through TCAD simulator. We also discussed the influence of temperature on linearity parameters like gm2, gm3, VIP2, VIP3, IMD3, IIP3, and 1-dB compression point. A comparative study between DMG and single material gate (SMG) FinFET is also investigated.

Temperature effect on RF/analog and linearity parameters in DMG FinFET

In this article, a $\delta $ -doped germanium-source vertical TFET (Ge-source vTFET) is proposed and investigated by Synopsis TCAD simulation. Higher ON-state current is obtained as the electron tunneling takes place in a direction parallel to the gate electric field. The incorporation of the $\delta $ -doped layer in the germanium source region further reduces the OFF-state leakage current. The impact on the variation of the device geometric dimensions has been studied for various electrical parameters and the dimensions are optimized accordingly through extensive simulations. A very high current ratio of the order ~1011 with a substantially low average subthreshold swing of 21.2 mV/decade is achieved. Benchmarking of the proposed Ge-source vTFET with other novel TFETs is carried out which produced better results in terms of high ON -state current and SSavg. The results obtained for the proposed vTFET make it a potential candidate for ultralow-power applications.

Brinda Bhowmick

Papers

Comparative Analyses of Circular Gate TFET and Heterojunction TFET for Dielectric-Modulated Label-Free Biosensing

N+ Pocket Doped Vertical TFET Based Dielectric-Modulated Biosensor Considering Non-Ideal Hybridization Issue: A Simulation Study

Temperature effect on RF/analog and linearity parameters in DMG FinFET

Investigation of a Ge-Source Vertical TFET With Delta-Doped Layer

Heterojunction fully depleted SOI-TFET with oxide/source overlap