Analysis and Simulation of Vertical Complementary Silicon Bipolar Transistors

A self-aligned vertical Bipolar Charge Plasma Transistor (V-BCPT) with a buried metal layer between undoped silicon and buried oxide of the silicon-on-insulator substrate, is reported in this paper. Using two-dimensional device simulation, the electrical performance of the proposed device is evaluated in detail. Our simulation results demonstrate that the V-BCPT not only has very high current gain but also exhibits high BVCEO · fT product making it highly suitable for mixed signal high speed circuits. The proposed device structure is also suitable for realizing doping-less bipolar charge plasma transistor using compound semiconductors such as GaAs, SiC with low thermal budgets. The device is also immune to non-ideal current crowding effects cropping up at high current densities.

In this Letter, a novel vertical bipolar junction transistor (BJT) triggered silicon‐controlled rectifier (VBTSCR) is proposed for advanced nanoscale electrostatic discharge (ESD) protection applications. With the help of a vertical NPN transistor in floating base configuration, the new silicon‐controlled rectifier (SCR) structure achieves lower trigger voltage and better clamping capacity than the prior enhanced modified lateral SCR (EMLSCR) under the same layout footprint. The ESD characteristics are measured using the transmission line pulsing tester. Compared with that of EMLSCR, the trigger voltage of VBTSCR drops by 1 V, and the effective ESD robustness of VBTSCR has been doubled significantly. Based on these advantages, the proposed VBTSCR can provide ESD protection for the advanced 1.8/2.5 V input/output circuits more efficiently.

A new dc measurement technique that allows a direct observation of the Early effects and the base push-out effect in vertical bipolar transistors is described. The technique uses a special test structure and may be used to accurately determine the forward and reverse Early voltages used in the Gummel Poon model. The improvements provided by this method over conventionally used parameter extraction techniques are demonstrated through measurements on silicon and through two-dimensional device simulations.

To improve the value of β of a pnp-merged vertical bipolar transistor (VBT) in ‘pseudo-BiCMOS’ technology, a novel VBT design with an inversion layer-extended emitter is proposed. A high emitter injection efficiency of the forward-biased inversion layer is demonstrated in a pnp VBT fabricated in 1 µm compensated CMOS technology.

Axial force is one of the main factors which affect the pump safety and reliability during the operation of pumps, especially in multi-stage centrifugal pumps. 150QJ20 type deep-well centrifugal pump (DCP) is selected as an example to research the pump performance and axial force with the numerical simulation and experiment method. The numerical simulation results were compared with experimental measurements, and such result was analyzed. The results show that the change trend of the pump performance and axial force acquired by numerical and experiment is similar. At rated operating point, the error of axial force between the numerical simulation and experimental measurements is less than 3%. This confirmed the feasibility of predict the pump performance by numerical simulation method.

Does complementary technology within an ecosystem affect disruptive innovation? Evidence from Chinese electric vehicle listed firms

To research the dynamic characteristics of a planar piezoelectric six-axis force/torque(F/T) sensor in an actual measurement, a mathematical model method, a simulation method, and a calibration method are presented. The structure model of the sensor, its working principle, and research method are explained. A mass-spring equivalent model with multi-degrees of vibration based on the sensor is established, and differential equations based on the vibration system are derived from this model. According to the experimental prototype parameters of the sensor, its numerical model is established, the numerical simulation method and dynamic characteristic are investigated, and the amplitude–frequency and phase–frequency characteristics are analysed using the harmonic response method. The natural frequency of this sensor is calibrated using the impact response method. The experimental results indicate that the natural frequency in the six directions of the planar piezoelectric six-axis F/T sensor is higher than 3.95 kHz, and that the results of the analytical mathematical method and numerical simulation method are consistent with the calibration results. The proposed analytical mathematical method, simulation method, and calibration method can be used in the design, prediction, and calibration of the dynamic characteristics of these six-axis F/T sensors.

The present paper proposes a numerical simulation method for analyzing water impact on elastic structures.In order to accurately evaluate the structural strength of marine structures under severe water impact, the characteristics associated with the dynamic structural response to an impact load, the magnitude of which changes rapidly, must be examined. Until now, a simplified two-step method has been widely used for this purpose. This method entails estimation of a time series of the hydrodynamic force on a structure, assuming that the body is rigid. This is followed by response analysis of the structure by applying the previously estimated force history. However, when the structure is relatively flexible, the two-step method may not be applicable because it neglects the coupling effect between the fluid and structure. Thus, a numerical simulation method that considers fluid-structure coupling is prepared. The new method consists of two components, i.e., a 2-D numerical simulation method that utilizes the computational fluid dynamics (CFD) for flow field analysis and a modal analysis technique for solving the dynamic structural response of the cylindrical shell in its transverse section. Information such as fluid pressure, motion and deformation of the structure, is exchanged between the two components at each time-step of the numerical simulation. A series of drop model experiments was also conducted to verify the accuracy of the newly developed numerical simulation method. The experiments consisted of dropping a cylindrical model made of an aluminium plate onto a still water surface. The motion of the model and strain on the shell plate were measured. Experimental data taken from a published report were also used for comparison.The following results were obtained : 1. In the case of a light-weight model, the rigid body motion of the dropped model changed remarkably upon impacting the water surface. This deceleration influenced the pressure field around the model remarkably as well as the elastic response of the model structure, i.e., strain-time history. The accuracy of the numerical simulation was improved substantially by considering the deceleration effect of the rigid body motion during water entry.2. Although the predicted elastic response by the two-step method agreed fairly well with measured response in the case of a cylinder with high rigidity, the method cannot predict the elastic response of a cylindrical shell with low rigidity. By carrying out the above mentioned coupling simulation, the accuracy of the computed elastic response becomes noticeably improved. Thus, the proposed simulation method appears to be effective.

In this paper, the numerical simulation method for the protection performance of liquid armor based on STF can be roughly summarized into two ways, containing the shell element simulation method based on the inter-yarns friction coefficient and the coupled Euler-Lagrangian simulation method. The shell element simulation method of inter-yarns friction coefficient has a single consideration for STF performance, but it has high calculation efficiency and low calculation cost. The coupled Euler-Lagrangian simulation method fully considers the shear thickening characteristics of STF, and comprehensively considers the characteristics of STF. The simulated performance gets closer to the actual situation, and it can also reveal the effect of STF in improving the protection performance.

Most of the semiconductor device geometries that are being experimented with for improved magnetic field sensing do not lend themselves to accurate analytical modeling. The vectorial interaction taking place between the electrical current and the magnetic field complicates the problem of solving nonlinearly coupled carried density and electrostatic potential equations. In this work, solutions to the carrier density and electrostatic potential distributions are obtained by using a finite-element technique for a structure representing lateral and vertical bipolar transistors with multiple collectors. The results presented show the effect of the magnetic field to be very nonuniformly distributed around the emitter with a heavy-concentration near the emitter edges where the Lorentz-force-driven carriers are stopped at the insulating boundaries and give rise to a magnetoconcentration in the carrier densities. Distribution of currents collected by a multitude of collectors surrounding the emitter and their sensitivity to the magnetic field are given. The vertical magnetosensitivities are found to be an order of magnitude smaller than the lateral magnetosensitivity because of the lack of such a magnetoconcentration of carriers under the emitter. The computer program developed can simulate unipolar as well as bipolar magneto-sensitive devices with any boundary geometry.< <ETX xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">&gt;</ETX>

Optimal design of acoustic performance for automotive air-cleaner

To investigate the structural integrity of solid propellant under low temperature ignition impulsion conditions, this paper employs the generalized nonlinear Zhu-Wang-Tang (ZWT) constitutive model with four Maxwell elements, where the parameters of the constitutive model are obtained combining the tensile test data and slime mold algorithm (SMA). Based on the secondary development function of UMAT of the ABAQUS finite element analysis software, this constitutive model is then adopted to numerically simulate the propellant uniaxial tensile test under constant strain. The simulation results were compared with experimental data to validate the reliability of the numerical simulation method. Finally, this numerical simulation method is used to study the structural integrity of 5-pointed star HTPB solid propellant under curing cooling and ignition impulsion conditions at −30°C. The results show that the SMA has faster convergence and higher accuracy than commonly used ant colony optimization. The uniaxial tensile simulation results of the propellant under constant strain are consistent with the experimental results, which verifies the dependability of the constitutive model and the numerical simulation method. The HTPB solid propellant under the conditions of curing cooling and ignition impact at different ignition pressures (10, 12, 15, and 20 MPa) is also applicable to the HTPB solid propellant under different ignition pressures. The maximum equivalent stress and equivalent strain values of HTPB solid propellant under curing cooling and different ignition impulsion pressures (10, 12, 15, and 20 MPa) all appeared at the transition arc of the grain. The structural integrity of the grain is not damaged within 20 MPa ignition pressure at a low temperature of −30°C.

The lithology of the roof of the mining roadway is compound and the thickness of each layer varies considerably, and it is disturbed by dynamic load all the year round. The above factors has caused a huge difference in the stability of the roadway surrounding rock. Taking the 11,020 lower tunnel of a mine in Henan Province as the engineering geological background, using on-site investigation, formula derivation, numerical simulation and other methods, the composite roof roadway model group was established to study the deflection evolution characteristics of the surrounding rock under dynamic load disturbance, and summarize the plastic zone of the surrounding rock of the roadway Deformation and evolution of roof surrounding rock to evaluate the stability of surrounding rock with different roof structures. The research results show that the change of the roof surrounding rock structure will also lead to the change of the center deflection of the roadway roof. Therefore, the center deflection of the surrounding rock of various roof composite structures is different, and the deflection is the most direct indicator of the stability of the surrounding rock. The center deflection (\(\omega_{0}\)) of the soft rock type is the largest, the center deflection (\(\omega_{0}\))of the upper soft and the lower hard type, and the soft and hard type is larger, and the soft and hard progressive type, thin, hard and thick soft type (\(\omega_{0}\)) is the smallest, and the dynamic load The relationship between the magnitude of deflection before and after the disturbance is consistent. By constructing a composite roof roadway numerical model group, using the plastic failure zone of the roadway as the evaluation standard, the surrounding rock stability is evaluated and divided, and then the cross-point field measurement method is used to verify the stability of the surrounding rock on the roof of different composite structures. And the development of composite roof roadway surrounding rock deformation and failure mechanism and numerical simulation method has important theoretical significance and practical value for the analysis and control of composite roof roadway surrounding rock stability.

ABSTRACTA convergence identification method for oscillatory numerical simulation is proposed, in which the numerical solution can converge at the inflection point with respect to the time step. In addition, an algorithm to verify the appropriate time step is also proposed. The feasibility of the proposed method is further verified by its application to a case study involving combined natural and magnetohydrodynamics convection in a Joule-heated cavity using finite-volume methods. It is found that the two approaches have the same results and can judge the validity of the time step used in accurate computation of fluid flow and heat transfer.

A fractional rheological model was developed for MRE-based isolation systems to investigate the influence of material elasticity and viscosity on the isolation effect. The identification of model parameters was realized by fitting experimental data of dynamic mechanical analysis for MRE structures. The superior rationality of modeling was reflected with the good consistency and repeatability. The transmissibility was calculated both theoretically and numerically. The method of numerical simulation was verified with an excellent agreement between theoretical and numerical results. The influence of model parameters on transmissibility and energy flow was analyzed to interpret the dynamic behavior of vibration isolation systems. A control strategy based on the coincidence frequency was developed for this MRE-based isolation system to protect the foundation or the sensitive equipment against periodic vibrations. The isolation effect was investigated from the prospect of transmissibility and energy flow. Eventually, the fuzzy control algorithm was adopted to isolate the sensitive equipment against random motions of the ground, and the effectiveness was further validated by comparing with the passive isolation.