“…This is because, as Germanium concentration increases intrinsic carrier density increases and hence it would be better to choose a mole-fraction which can give high carrier density without reducing the mobility of carriers at the pocket-channel material junction for this device. Usage of Si 1-x Ge x mole fraction has also shown to reduce the gate to drain capacitance in the past which greatly effects gain bandwidth product (GBP) 40 . Figure 1 ( a ) Schematic structure of poc-DG-AJLTFET.…”
Section: Device Description and Simulationmentioning
This work is intended to design a quadrature phase shift keying (QPSK) system starting from the device design, characterization and optimization which is then followed by the circuit level implementation and finally the system level configuration. Tunnel Field Effect Transistor (TFET) technology came into existence because of the inability of CMOS (Complementary Metal Oxide Semiconductor) to produce reduced leakage current (Ioff) in the subthreshold regime. With the effects of scaling and requirement of high doping concentrations, TFET is not capable to produce stable reduction in Ioff due to the variation in ON and OFF current. To improve the switching ratio of the current and to obtain good subthreshold swing (SS) by overcoming the limitations of junction TFET, a new device design is proposed for the first time in this work. A pocket double gate asymmetric Junction less TFET (poc-DG-AJLTFET) structure has been proposed in which uniform doping is used to eliminate the junctions and a pocket of length 2 nm made of Silicon–Germanium (SiGe) material has been introduced to improve the designed structure performance in the weak inversion region and increase the drive current (ION). The work function has been tuned to produce the best results for poc-DG-AJLTFET and with our proposed poc-DG-AJLTFET, effects of interface traps are eliminated as against conventional JLTFET structures. The notion that low-threshold voltage device yields high IOFF has been proved wrong with our poc-DG-AJLTFET design, as it produced low threshold voltage with lower IOFF which reduced the power dissipation. Numerical results show that drain induced barrier lowering (DIBL) of 2.75 mV/V is achieved which could be less than 35 times required for short channel effects to be minimum. In terms of gate to drain capacitance (Cgd), it is found that ~ 103 reduction which greatly improves device inertia to internal electrical interference. Also, improvement in transconductance is achieved by 104 times, 103 times improvement in ION/IOFF ratio, and 400 times higher unity gain cutoff-frequency (ft) which would be required by all communication systems. The Verilog models of the designed device are used to construct the leaf cells of quadrature phase shift keying (QPSK) system and the implemented QPSK system is taken as a key evaluator in the performance evaluation in terms of propagation delay and power consumption of poc-DG-AJLTFET in modern satellite communication systems.
“…This is because, as Germanium concentration increases intrinsic carrier density increases and hence it would be better to choose a mole-fraction which can give high carrier density without reducing the mobility of carriers at the pocket-channel material junction for this device. Usage of Si 1-x Ge x mole fraction has also shown to reduce the gate to drain capacitance in the past which greatly effects gain bandwidth product (GBP) 40 . Figure 1 ( a ) Schematic structure of poc-DG-AJLTFET.…”
Section: Device Description and Simulationmentioning
This work is intended to design a quadrature phase shift keying (QPSK) system starting from the device design, characterization and optimization which is then followed by the circuit level implementation and finally the system level configuration. Tunnel Field Effect Transistor (TFET) technology came into existence because of the inability of CMOS (Complementary Metal Oxide Semiconductor) to produce reduced leakage current (Ioff) in the subthreshold regime. With the effects of scaling and requirement of high doping concentrations, TFET is not capable to produce stable reduction in Ioff due to the variation in ON and OFF current. To improve the switching ratio of the current and to obtain good subthreshold swing (SS) by overcoming the limitations of junction TFET, a new device design is proposed for the first time in this work. A pocket double gate asymmetric Junction less TFET (poc-DG-AJLTFET) structure has been proposed in which uniform doping is used to eliminate the junctions and a pocket of length 2 nm made of Silicon–Germanium (SiGe) material has been introduced to improve the designed structure performance in the weak inversion region and increase the drive current (ION). The work function has been tuned to produce the best results for poc-DG-AJLTFET and with our proposed poc-DG-AJLTFET, effects of interface traps are eliminated as against conventional JLTFET structures. The notion that low-threshold voltage device yields high IOFF has been proved wrong with our poc-DG-AJLTFET design, as it produced low threshold voltage with lower IOFF which reduced the power dissipation. Numerical results show that drain induced barrier lowering (DIBL) of 2.75 mV/V is achieved which could be less than 35 times required for short channel effects to be minimum. In terms of gate to drain capacitance (Cgd), it is found that ~ 103 reduction which greatly improves device inertia to internal electrical interference. Also, improvement in transconductance is achieved by 104 times, 103 times improvement in ION/IOFF ratio, and 400 times higher unity gain cutoff-frequency (ft) which would be required by all communication systems. The Verilog models of the designed device are used to construct the leaf cells of quadrature phase shift keying (QPSK) system and the implemented QPSK system is taken as a key evaluator in the performance evaluation in terms of propagation delay and power consumption of poc-DG-AJLTFET in modern satellite communication systems.
“…Increasing gate numbers can also decrease λ according to (1), and that is why FinFET with three sides of the channel surrounded by the gates performs better than planar FET in regards to suppressing SCE [8]. Recently, GAA-FET has been predicted to replace FinFET and dominate the semiconductor market for 3 nm technology node and beyond, since GAA-FET has better gate control and stronger SCE suppression ability than FinFET attributing to its surrounding gate structure [9].…”
With transistors scaling down to 3 nm node and beyond, short channel effect (SCE) as well as power consumption dissipation present immense challenges for further scaling down of the transistor. Hence the Gate all around field effect transistor (GAA-FET) is proposed to replace the Fin field effect transistor (FinFET) in 3 nm technology node and beyond due to its better gate control over the channel with surrounding gate structure, thus providing improved SCE constraint ability. Traditional transistors suffer from the problems of "Boltzmann Tyranny" and cannot overcome the subthreshold swing (SS) limit of 60 mV/dec at room temperature. To maintain high Ion and avoid Ioff from increasing too much, supply voltage (VDD) of the conventional transistor cannot scale down proportionally with the dimension of the transistor. The concept of negative capacitance (NC) has been demonstrated to be able to obtain sub-60 mV/dec SS with the ability of amplifying the potential of the channel region without VDD increment. The novel device structure of negative capacitance gate all around field effect transistor ( NC GAA-FET) can combine both the advantages of GAA-FET and NC-FET, and is the most promising ultra-low power consumption device and promises to sustain the Moore's law further beyond what is predicted now. Whereas, according to our knowledge, there have been few review papers about NC GAA-FET till now. Herein, we summarize the recent advances of the NC GAA-FET both in simulation and experimental aspects, which we believe will bring about profound changes to the further development of NC GAA-FET devices.INDEX TERMS Negative capacitance effect, short channel effect, subthreshold swing, power consumption dissipation, negative capacitance gate all around field effect transistor.
“…When using such consumable quartz parts for the process equipment, they can easily generate particles and gases of metal impurities when they are exposed to high-temperature and -pressure processes [ 6 ] because their raw material is purified from natural rocks with an impurity level of up to 10 ppm in metal ions such as Fe, Al, Ni, and Zn. Recently, since the channel length of metal–oxide–semiconductor field-effect transistors (MOSFETs) has been scaled down to 3 nm to achieve faster speed, lower power consumption, and higher integration density [ 7 ], ultra-high-purity synthetic quartz powder with an impurity level of less than 100 parts per billion (ppb) in metal ions is essential so that the fabricating devices are not contaminated by metallic impurities generated from such quartz parts during the fabrication process [ 8 , 9 ]. In addition, for quartz crucibles used in Czochralski technology, a 3 nm thick inner layer of quartz crucible is fabricated by fusing and coating synthetic quartz powder instantaneously on the inner surface of a quartz crucible formed of natural quartz through the arc plasma process.…”
Fumed silica-based ultra-high-purity synthetic quartz powder was developed via the sol–gel process to apply to quartz wares and quartz crucibles for use in advanced semiconductor processes. The process conditions of preparing potassium silicate solution, gelation, and cleaning were optimized, i.e., the relative ratio of fumed silica (10 wt%) to KOH (4 wt%) for potassium silicate solution, gelation time 3 h, and cleaning for 1 h with 5 wt% HCl solution. It was observed that the gelation time strongly affected the size distribution of the quartz powder; i.e., a longer gelation time led to a larger size (d50) of the synthesized quartz powder: 157 μm for 2 h and 331 μm for 5 h. In particular, it was found that the morphology of the as-synthesized quartz powder greatly depended on the pulverizing process; i.e., the shape of quartz powder was shown to be rod-shaped for the without-gel-pulverizing process and granular-shaped with the process. We expect that the fumed silica-based ultra-high-purity quartz powder with an impurity level of 74.1 ppb synthesized via the sol–gel process is applicable as a raw material for quartz wares and crucibles for advanced semiconductor processes beyond the design rule of 3 nm.
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