Bipolar Transistor Model Research Articles

Modeling of a New SOI Bidirectional Bipolar Junction Transistor for Low-Loss Household Appliances

In this paper, a new monolithic bidirectional bipolar junction transistor with full turn-off control is studied due to technology computer-aided tools. The structure is built on a symmetrical transistor using silicon-on-insulator technology, which functionality relies on reduced surface field and base shielding effects. These concepts allow high drift doping concentrations and a thin and/or lowly doped base. Such a structure is suitable for bidirectional household appliances within a confined environment where power dissipation is a critical parameter.

Monitoring of the current-distribution uniformity in bipolar transistors from the dependence of internal-feedback factor on collector voltage

On the basis of the two-section model of a high-power bipolar transistor, it is shown that the slope of dependence of the small-signal feedback coefficient on the collector voltage in the presence of defects in the transistor is proportional to the defect size. The setup for the automated monitoring of the current-distribution nonuniformity in the transistor device structure from the indicated dependence with using the combination of linearly increasing and small harmonic variations in the collector voltage is described. The experimental dependences confirming the results of the theoretical analysis are presented.

A Physics-Based Device Model of Transient Neutron Damage in Bipolar Junction Transistors

For the purpose of simulating the effects of neutron radiation damage on bipolar circuit performance, a bipolar junction transistor (BJT) compact model incorporating displacement damage effects and rapid annealing has been developed. A physics-based approach is used to model displacement damage effects, and this modeling approach is implemented as an augmentation to the Gummel-Poon BJT model. The model is presented and implemented in the Xyce circuit simulator, and is shown to agree well with experiments and TCAD simulation, and is shown to be superior to a previous compact modeling approach.

Physics-Based Model of Planar-Gate IGBT Including MOS Side Two-Dimensional Effects

An existing physics-based insulated gate bipolar transistor (IGBT) model, which has been proven accurate for both inductive turn-off and inductive turn-on simulations, is modified to account for planar-gate IGBT 2-D effects at the MOS end of the drift region. The modification is based on a steady-state solution of carrier distribution in the JFET region of the IGBT. The accuracy of this solution is verified through a set of finite element simulations. The improved accuracy of the modified model in terms of on-state forward drop and voltage tail at turn-on is verified through comparison with experimental results.

Interpreting Transistor Noise

The simple noise models of field effect and bipolar transistors reviewed in this article are quite useful in engineering practice, as illustrated by measured and modeled results. The exact and approximate expressions for the noise parameters of FETs and bipolar transistors reveal certain common noise properties and some general noise properties of both devices. The usefulness of these expressions in interpreting the dependence of measured noise parameters on frequency, bias, and temperature and, consequently, in checking of consistency of measured data has been demonstrated.

Direct Parameter Extraction Of Base and Emitter Resistances For SiGe HBTs Using DC Data Only

A new method to directly extract base and emitter resistance parameters for SiGe HBTs using the Mextram bipolar compact transistor model has been presented. The method only requires a standard forward Gummel measurement and accounts for several second order effects like high-injection base conductivity modulation, Early effect and emitter current crowding. Base and emitter resistance parameters have been extracted over a wide temperature range (300K - 93K) for a first generation 0.5µm SiGe HBT with a peak cut-off frequency of 50 GHz at 300K. The HBT features a heavily doped poly-silicon emitter, an extrinsic base region doped well above the Mott's transition (3e18 cc for boron in silicon) and an intrinsic base region doped very close to the Mott's transition. The extracted parameters have been verified by comparison with several different methods.

High-frequency log-domain current-mode multiphase sinusoidal oscillator

This study describes the design of a multiphase sinusoidal oscillator (MSO) based on log-domain filtering concept. The circuit is a direct realisation of a first-order differential equation for obtaining the inverting and non-inverting low-pass filters. Each low-pass filter comprises only a grounded capacitor and four transistors. The proposed MSO can be instantaneously controlled over a very wide frequency range by controlling the current for the oscillation frequency and oscillation condition which indicates the proposed MSO's suitability in high-frequency applications. A validated bipolar junction transistor (BJT) model is used in SPICE simulation operated from a single power supply as low as 2.5 V. The oscillation frequency is controlled over four decades of frequency. The total harmonic distortions for three phase (11.5 MHz) and four phase (7 MHz) are, respectively, obtained around 2.4 and 2.2% which enables them to be fully integrated in telecommunication systems. The power consumption is around 5.5 mW for 100 µA bias current. Moreover, experimental results of three-phase MSO are included.

The Superjunction Insulated Gate Bipolar Transistor Optimization and Modeling

In this paper, we present a detailed analysis and optimization of the superjunction (SJ) insulated gate bipolar transistor (IGBT). The SJ IGBT is a new device that breaks the IGBT limits, i.e., it delivers performance that is dramatically better. More specifically, we demonstrate here that the optimized SJ IGBT can deliver turn-off losses that are at least 50% lower than those of the state-of-art IGBT while maintaining a similarly low on-state performance, both at room temperature and at higher temperatures. The presence of alternating p- and n-pillars in the drift region gives rise to unique characteristics that when optimized can deliver superior performance. This paper also presents a SPICE model of the SJ IGBT under optimized conditions. Its results are in good agreement with the DESSIS simulation results under direct current conditions. This model consists of an intrinsic MOSFET and a parallel combination of wide- and narrow-base p-n-p bipolar junction transistors.

Modeling of a heterojunction bipolar transistor based AlGaAs / GaAs

The simulation of the physical components semiconductor uses approximations varied depending on the type of devices to study and expected effects. Also, the systems obtained are rarely simple to solve. Numerically, the transportation problems are most difficult to discrete. It should also be noted that the problem is strongly nonlinear, coupling quantities very heterogeneous and are not at all in the same order of size. It should be noted moreover than the exploitation of the physical models can be conceived only if the computing times remain reasonable. The physical model as simple implemented for HBT transistors is the model of drift diffusion. This model is given in the form of differential equations in partial derivatives, describing the physical behavior of charges and currents in each part of the device. The objective of our work consists in studying the electronic properties of a heterojunction bipolar transistor based AlxGa1-xAs /GaAs, and the distribution of electric potential, of the field electric thus the concentration of the electrons and the holes.

Modeling of MOS-Side Carrier Injection in Trench-Gate IGBTs

A compact trench-gate insulated-gate bipolar transistor model that captures MOS-side carrier injection is developed. The model retains the simplicity of a 1-D solution to the ambipolar diffusion equation, but at the same time, captures the MOS-side carrier injection and its effects on steady-state carrier distribution in the drift region and on switching waveforms.

An advanced physics-based sub-circuit model of a punch-trough insulated gate bipolar transistor

An advanced sub-circuit model of the punch-trough insulated gate bipolar transistor (PT IGBT) based on the physics of internal device operation has been described in this article. The one-dimensional physical model of low-gain wide-base BJT is employed based on the equivalent non-linear lossy transmission line, whereas a SPICE Level 3 model is used for the diffused MOST part. The influence of voltage dependent drain-to-gate overlapping capacitance and the conductivity modulated base (drain) ohmic resistance are modelled separately. The main advantages of novel PT IGBT model are a small set of model parameters, an easy implementation in SPICE simulator and the high accuracy confirmed by comparing the simulation results with the electrical measurements of test power circuit.

A Physics-Based Charge-Control Model for InP DHBT Including Current-Blocking Effect

We develop a physics-based charge-control InP double heterojunction bipolar transistor model including three important effects: current blocking, mobile-charge modulation of the base-collector capacitance and velocity-field modulation in the transit time. The bias-dependent base-collector depletion charge is obtained analytically, which takes into account the mobile-charge modulation. Then, a measurement based voltage-dependent transit time formulation is implemented. As a result, over a wide range of biases, the developed model shows good agreement between the modeled and measured S-parameters and cutoff frequency. Also, the model considering current blocking effect demonstrates more accurate prediction of the output characteristics than conventional vertical bipolar inter company results.

Thermal Resistance Model for Multi-finger Trench-Isolated Bipolar Transistors on SOI Substrate

A simple predictive model to estimate the thermal resistance of a trench isolated multi-finger bipolar device on SOI substrate is proposed. The model shows very good agreement with 3-D electro-thermal simulations over a wide range of device parameters. The simulations have been verified with measurements. The model is virtually independent of critical device parameters such as trench depth, oxide layer thickness and emitter dimensions and serves as a useful tool to predict the thermal resistance of a multi-emitter device reasonably accurately, from the known thermal resistance of the corresponding single-emitter device.

Thermal Resistance Model for Multi-finger Trench-Isolated Bipolar Transistors on SOI Substrate

not Available.

Finite-Element Modeling and Optimization-Based Parameter Extraction Algorithm for NPT-IGBTs

<para xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> A finite-element, physics-based, non-punch-through (NPT) insulated gate bipolar transistor (IGBT) model is presented in this paper. The model's core is based on solving the ambipolar diffusion equation through a variational formulation, resulting in a system of ordinary differential equations (ODEs). The approach enables an easy implementation into a standard SPICE circuit simulator. The resulting system of ODEs is solved as a set of (current controlled) <emphasis emphasistype="italic">RC</emphasis> nets describing charge carrier distribution in a low-doped zone. Other zones of the device are modeled with classical methods. This hybrid approach describes the device's dynamic and static behavior with good accuracy while maintaining low execution times. As physics-based models need a significant number of parameters, an automatic parameter extraction method has been developed. The procedure, based on an optimization algorithm (simulated annealing), enables an efficient extraction of parameters requiring some simple device waveform measurements. Experimental validation is performed. Results prove the usefulness of the proposed methodology for the efficient design of power circuits through simulation. </para>

A physical-model of small-signal InP-based double heterojunction bipolar transistors and its parameter extraction technique

The influence on the base-collector junction capacitance Cbc of the energy band structure of the InP heterojunction bipolar transistors is researched. A physical model of small-signal InP double heterojunction bipolar transistor （DHBT） is developed, which takes into account the base-emitter and collector-emitter metalisations by using two additional capacitances Cmb and Cmc. The resistance of the model is divided into the intrinsic resistance, the extrinsic resistance and the parasitic resistance. Meanwhile, a physically meaningful small-signal parameter extraction procedure for the model is presented, in which all the equivalent circuit elements are extracted without reference to numerical optimization. An experimental validation is carried out, and excellent results are obtained over a wide range of bias points, which demonstrates good modeling accuracy.

Analytical Model and Current Gain Enhancement of Polysilicon-Emitter Contact Bipolar Transistors

<para xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> This paper presents an analytical model that simulates the current gain improvement of polysilicon-emitter bipolar transistors based on the effective recombination velocity method. The theoretical framework developed in this paper incorporates the 2-D structure effect of the polysilicon layer with columnar grain boundary, tunneling processes of holes through polysilicon/silicon interface oxide layer, and nonuniform doping concentration and bulk recombination effects in the single-crystal emitter. The study goes on to derive an analytical expression for the base current density from which the analytical expression of the current gain was then derived. The effect of oxide breakup, at the polysilicon/silicon interface, on current gain was also considered. The dependence of the current gain on temperature was analyzed numerically; the results are in good agreement with experimental data. The approach outlined in this paper allows one to avoid many of the unnecessary simplifications inherent in previous works and to clearly assess the relevance of each physical mechanism. </para>

A Distributed Millimeter-Wave Small-Signal HBT Model Based on Electromagnetic Simulation

In this paper, a novel distributed small-signal heterojunction bipolar transistor (HBT) model at millimeter-wave frequencies is proposed. This new approach integrates the electromagnetic (EM) simulation of the outer extrinsic passive part of an HBT, the coupled transmission lines for the fingers, and the Gupta multiport connection into an efficient global distributed modeling approach. For the first time, the values of the entire HBT intrinsic model elements used in the active elementary cells (AECs) can subsequently be extracted through the explicit analytical expressions derived through the multiport connection method. Good agreement between the measured and the simulated results has been demonstrated. This model has several unique advantages for microwave transistor optimization and synthesis in that the derived explicit analytical expressions are in terms of the effect of the extrinsic parts, allowing the designer to have better control over the whole transistor design. Furthermore, it serves as one of the valuable steps toward global modeling of millimeter-wave devices and circuits.

Differential Type Class-AB Second-Order Log-Domain Notch Filter

In this paper, a new current-mode second-order differential type Class-AB log-domain notch filter is proposed. It is systematically designed using state-space synthesis method. The filter circuit is current-mode, Class-AB and differential type. In the circuit, the input and the output values, and dominant variables are all currents. Input and output currents are also differential signals. Only transistors and grounded capacitors are required to realize the filter circuit. Three cases of the second-order notch filter were obtained. The regular notch was obtained when omega <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">n</sub> =omega <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">0</sub> , the low-pass notch was obtained when omega <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">n</sub> >omega <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">0</sub> , and the high-pass notch was obtained when omega <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">n</sub> >omega <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">0</sub> . The center frequency, the notch frequency, the quality factor, and gain of the filter can be electronically tuned by changing external currents. Time and frequency-domain simulations are performed using PSPICE program for the filter to verify the theory and to show the performance of it. For this purpose, the filter is simulated by using idealized bipolar junction transistor models and AT&T CBIC-R (NR200N-2X NPN), (PR200N-2X PNP) type transistors.

Extraction of the InP/InGaAs metallic collector-up heterojunction bipolar transistor small-signal equivalent circuit

An efficient technique for determining the small-signal equivalent-circuit model of a Metal collector-up Heterojunction Bipolar Transistor (C-up MHBT) is presented. The technique employs analytically derived expressions for direct calculation of HBT T-Model equivalent circuit element values in terms of the measured S-parameters. This approach avoids errors due to uncertainty in fitting to large, over determined equivalent circuits and does not require the use of test structures and extra measurement steps to evaluate parasitics. Physically realistic results are demonstrated under various biasing conditions for the n-p-n InP/InGaAs HBT with metallic collector up structure. The agreement between the measured and model-produced data is excellent over the large frequency range and for several polarizations conditions for devices.