The dual gate base resistance controlled thyristor

A new device concept, called the dual gate base resistance controlled thyristor (DG-BRT), is introduced for simultaneously obtaining the low on-state voltage drop of a thyristor together with a good forward biased safe operating area. The two gates are used to control an N-channel and a P-channel MOSFET integrated with a thyristor structure using the DMOS process. When a positive bias is applied to both gates, the device operates in the thyristor-mode with a low on-state voltage drop at even high current densities. When a negative bias is applied to the OFF-gate, the device operates in the IGBT-mode with the saturated current controlled by the positive bias applied to the ON-gate. The results of two-dimensional numerical simulations and measurements performed on devices with 600 V forward blocking capability are reported     

Floating base thyristor

The floating base thyristor (FBT) is a new thyristor structure in which its p-base region, containing a p⁺ region is not shorted to the n⁺ emitter. Using the DMOS process, an n-channel and a p-channel MOSFET are integrated with the thyristor structure. The device operates in the thyristor mode with a low ON-state voltage drop at even high current densities when a positive bias is applied to, both gates. When a negative bias is applied to the OFF gate, the device operates in the IGBT mode with the saturated current controlled by the positive bias applied to the ON gate     

A novel single gate MOS controlled current saturated thyristor

A novel single gate MOS controlled current saturation thyristor (MCST) device is proposed. In the on-state the MCST operates in thyristor-like mode at low anode voltage and enters the IGBT-like mode automatically with increasing anode voltage, offering a low on-state voltage drop and current saturation capability. Simulation results based on 6.5 kV trench devices indicate the turn-off energy loss of the MCST is reduced by over 35% compared to the IGBT. The saturation current density of the MCST is strongly dependent on the on-set voltage of the p ⁺ buffer/n-well junction, leading to its excellent safe operation area (SOA) and making it suitable for high power applications     

The dual gate emitter switched thyristor (DG-EST)

A new device structure, called the dual gate emitter switched thyristor (DG-EST), is introduced for simultaneously obtaining on-state voltage drops lower than that of the conventional emitter switched thyristor (C-EST) and the high-voltage current saturation features of the Dual Channel EST (DC-EST). The DG-EST contains a DC-EST section and a C-EST section with a common thyristor section that can be controlled using two independent gate electrodes. When a positive bias is applied to both the gates, the device operates in a thyristor mode with the thyristor current constrained to flow through two lateral MOSFETs which minimizes the on-state voltage drop. When a “zero” bias is applied to the gate of the conventional EST, the device exhibits high-voltage current saturation, with the bias on the gate of the DC-EST controlling the saturated current. In this paper, the results of measurements performed on devices fabricated with a six-mask IGBT-like process are reported     

The injection efficiency controlled IGBT

An IGBT structure in which the anode injection efficiency changes with current density, the injection efficiency controlled IGBT (EEC-IGBT), is proposed. The anode injection efficiency of the IEC-IGBT is controlled via a current sensor inherent in its structure. Anode injection efficiency is strongly enhanced at low device current density and significantly reduced at high device current density. This enables the device to have a low on-state voltage drop (V_on) and superior safe operation area (SOA), making it very suitable for high-power applications. Simulation results based on 3.3 KV DMOS NPT devices indicate the on-state voltage drop of the IEC-IGBT is reduced by 0.6 V (20%) and the short-circuit SOA (SCSOA) is improved by several times compared to the conventional IGBT     

Theoretical and experimental characteristics of the base resistancecontrolled thyristor (BRT)

Described are the characteristics of a new MOS gated thyristor structure called the base resistance controlled thyristor (BRT), in which the turn-off of a thyristor built with an N drift region is achieved by reducing the resistance of the p-base region under MOS gate control. A p-channel MOSFET used to achieve turn-off is formed in the N drift region. The device is designed so that, when the p-channel MOSFET is switched on, holes are diverted from the p-base region of the thyristor into the adjacent p⁺ region, raising the holding current of the thyristor above the operating current level, and turning off the thyristor. Results of extensive 2-D numerical simulations that have been performed to demonstrate operation of this new device concept are discussed. Experimental results on 600-V devices fabricated with an IGBT process have corroborated theoretical predictions. Current densities above 900 A/cm² have been turned off at room temperature with a gate bias of -10 V     

A novel high performance insulated gate bipolar transistor

For the first time, a new concept of LDE-IGBT (local drift-region enhanced IGBT) is proposed and verified by two-dimensional (2D) device-circuit mixed simulations. The structure of the proposed device is almost identical to that of the conventional IGBT, except for an additional n⁺ plugged region under the gate contact. The proposed device exhibits larger maximum operating current, meaning higher current capability, which is expected for high-power operation. The simulation results indicate the LDE-IGBT can obtain a low on-state voltage drop with negligible increase of turn-off time due to lower sensitivity of turn-off time to the novel structure. Therefore, the trade-off relation between on-state voltage and turn-off time is improved and decoupled efficiently. Finally, the effects of three novel structure parameters on the on-state voltage are demonstrated in detail.     

具有P型浮空区的槽栅IGBT结构

本文提出了一种具有P型浮空层的新型槽栅IGBT结构,它是在之前所提的一种积累层沟道控制的槽栅IGBT(TAC-IGBT)基础之上引入了一浮空P型层。此结构在维持原有TAC-IGBT低的正向导通压降和更大正向偏置安全工作区（FBSOA）的同时,减小了器件的泄漏电流,提高了器件的击穿电压,也使得器件的短路安全工作区大大提高,且制造简单,设计裕度增大。仿真结果表明：对于1200V的IGBT器件,具有P型浮空层的新型槽栅IGBT结构漏电比TAC-IGBT小近一个量级,击穿电压提高近150V。     

New insulated-gate thyristor structure with MOSFET coupled baseregions

A new insulated-gate thyristor (IGTH) structure in which the base of n-p-n transistor is coupled to the base of p-n-p transistor through a MOSFET is described for the first time, In the new structure, called base coupled insulated gate thyristor (BC-IGTH), the parasitic lateral p-n-p carrier injection inherent in previously reported thyristor structures such as the MCT, BRT, and IGTH is absent. The absence of parasitic lateral p-n-p carrier injection results in low on state voltage drop and high controllable current capability for this structure. The turn-on process in the new structure is fundamentally different from other MOS-gated thyristor structures in that in the new structure, the higher gain n-p-n transistor is turned-on first, which then provides the base drive for the lower gain p-n-p transistor. Multicellular 800 V devices of the new thyristor structure were fabricated using a double-diffused DMOS process, and were found to give on-state drop of 1.1 V at 200 A/cm², and controllable currents in excess of 100 A/cm² were obtained by forming MOS-gate controlled emitter-to-base resistive shorts     

Trench gate IGBT structure with floating P region

A new trench gate IGBT structure with a floating P region is proposed,which introduces a floating P region into the trench accumulation layer controlled IGBT(TAC-IGBT).The new structure maintains a low on-state voltage drop and large forward biased safe operating area(FBSOA)of the TAC-IGBT structure while reduces the leakage current and improves the breakdown voltage.In addition,it enlarges the short circuit safe operating area(SCSOA)of the TAC-IGBT,and is simple in fabrication and design.Simulation results indicate that,for IGBT structures with a breakdown voltage of 1200 V, the leakage current of the new trench gate IGBT structure is one order of magnitude lower than the TAC-IGBT structure and the breakdown voltage is 150 V higher than the TAC-IGBT.     

High channel density dual operation mode MOS-controlled thyristorwith superior current saturation capability

A 1200-V dual operation mode MCT with low on state voltage drop, high turn-off current and superior current saturation capability has been developed. The dual operation mode MCT overcomes the tradeoff between the on-state voltage drop and the current saturation capability of the conventional IGBT operation by working in a thyristor mode in the on state and in an IGBT mode during the switching transient. This letter reports the device development and demonstrates how the dual operation mode MCT can be beneficial in switching circuit applications     

一种具有部分高介电常数介质调制效应的IGBT

提出了一种具有高介电常数介质填充沟槽的绝缘栅双极晶体管(IGBT).分析了高介电常数介质调制效应.结果表明,与普通场阻型IGBT相比,该器件的击穿电压提高了 8％,通态压降减小了 8％,关断损耗降低了 11％;在相同通态压降下,该器件的关断损耗降低了 35％.在栅极与原HK介质之间增加介电常数更高的介质,进一步提升了该...     

IGBT SPICE model

During the last few years, great progress in the development of new power semiconductor devices has been made. The new generation of power semiconductors is capable of conducting more current and blocking higher voltage. The IGBT (insulated gate bipolar transistor) is an outgrowth of power MOSFET technology. More like a MOSFET than a bipolar transistor in structure, the IGBT has some of the electrical characteristics of both. Like a MOSFET, the gate of the IGBT is isolated, and drive power is very low. The on-state conduction voltage of an IGBT is similar to that of a bipolar transistor. However, SPICE users are constantly faced with the inability to analyze circuits that contain devices that are not in the SPICE library of the semiconductor models. With the authors' own computer program, a complete macromodel of the IGBT for the SPICE simulator has been computed. In this paper, a complete IGBT SPICE macromodel is described and verified with experimental results     

Design of IGBT with integral freewheeling diode

A new power structure integrating a freewheeling diode in the termination region of a punch-through (PT) insulated gate bipolar transistor (IGBT) is presented. The proposed solution requires virtually no silicon area penalty with respect to a standard IGBT. Static and dynamic experimental results show the correct behavior of both IGBT and freewheeling diode. Further, it is shown that the lateral diode surrounding the multicellular IGBT can support IGBT direct current with low on-state voltage drop. The operation mechanisms of the composite structure and design techniques to improve structure dynamic behavior are investigated through two-dimensional numerical device simulations     

The asymmetrical field-controlled thyristor

A new device structure has been developed for field-controlled thyristors. In this structure, the uniformly doped n base of the conventional device has been replaced with a very lightly doped region near the gate and a more heavily doped region at the anode. This change in the base doping profile results in a significant improvement in the tradeoff between the forward-blocking voltage capability and the on-state forward-voltage drop. In addition, the high-resistivity region around the gate area allows the device to pinch off anode current flow at zero gate bias due to the built-in potential of the gate junction. The devices can, however, be triggered to the on-state by applying a small forward gate voltage and exhibit a forward voltage drop in the on-state which is much lower than that of conventional devices. The high resistivity of the channel area between gates also results in these devices having dc blocking gains in excess of 60, which is the highest value achieved in devices of this type. Further, because these devices have been fabricated using conventional planar processing techniques, this structure is suitable for high-volume production with high processing yields.     

A new lateral MOS-gated thyristor with controlling base-current

A new lateral MOS-gated thyristor, called the Base-Current-Controlled Thyristor, is described. This device is designed so that most holes at the on-stage reach the P base through the floating P⁺ region adjacent to the P base and the on-state MOSFET. At the turn-off stage, the interruption of the hole current to the P base due to switching off the above MOSFET occurs simultaneously with the conventional turn-off operation. The concept of this device is verified experimentally by using the fabricated lateral device with the external MOSFET. This device exhibits a better trade-off relation between the on-state voltage and the turn-off time compared uith the conventional MOS-gated thyristor     

The field-assisted turn-off thyristor: a regenerative device withvoltage-controlled turn-off

A solid-state switching element, the field-assisted turn-off (FATO) thyristor, has been developed. This is a regenerative device, which implies that it is capable of carrying very large current densities, with a very small forward voltage drop when it is in its on-state. Most regenerative devices cannot be turned off with a control signal; however, the structure of the FATO thyristor allows it to be switched off by applying a voltage to a high impedance, insulated-gate terminal. This device can also be fabricated with an insulated-gate turn-on structure, so that it is fully switchable using only low-current control signals. The design, fabrication, and characterization of the FATO thyristor are described     

Numerical analysis of turn-off characteristics for a gate turn-off thyristor with a shorted anode emitter

Turn-off current waveform for a gate turn-off thyristor (GTO) with a shorted anode emitter has been calculated numerically by solving the semiconductor basic equations in an equivalent one-dimensional model device. This model is derived from the analysis of current and carrier distributions obtained by a two-dimensional calculation of the on-state of GTO. A calculated turn-off current waveform agrees well with the experimental waveform. The computational time of one case is about 2 min. It is shown that this one-dimensional analysis method is useful for the calculation of the turn-off time. Using this one-dimensional model during the turn-off process and the two-dimensional model in the on-state, the relation between turn-off time and the forward voltage drop can be obtained in relation to the shorted emitter structure. It is shown that the shorted emitter structure is useful to improve this tradeoff relation.     

Insulated Gate P-I-N Transistor-a new MOS controlled switchingpower device

In this paper, a new monolithic MOS controlled power transistor structure called the Insulated Gate P-I-N Transistor (IGPT) is described for the first time and its operation is verified by two-dimensional numerical simulation. IGPT achieves an on-state voltage drop similar to that of a PIN diode, yet also provides insulated gate turn-off capability up to several thousand amperes per centimeter square. The turn-off of the IGPT is achieved by the MOS depletion of a high level injection region, verified also for the first time. IGPT is therefore a very attractive device to be used in high power switching applications because it is superior to current generation power devices such as the Insulated Gate Bipolar Transistor (IGBT) and MOS Controlled Thyristor (MCT)     

Effects of uni-axial mechanical stress on IGBT characteristics

This paper describes the impacts of mechanical stress on vertical power devices. The stress dependence of the DC characteristics of trench insulated gate bipolar transistors (IGBTs) was measured. The experimental results could be reproduced by the device simulation, which included stress dependence models of the carrier mobility and the band gap. We found that the stress dependence of the on-state voltage mainly arose from the MOSFET portion of the IGBT. Using the device simulation, we estimated the effects of mechanical stress on the surge voltage and the saturation current, which give us the important information for designing a power module with higher ruggedness.