Tomoyuki Yamazaki

A new vertical IGBT structure with a monolithic over-current, over-voltage, and over-temperature sensing and protecting circuit

A new 600 V vertical Insulated Gate Bipolar Transistor (IGBT) structure with monolithically integrated over-current, over-voltage, and over-temperature sensing and protecting functions has been developed to exploit an extremely excellent trade-off characteristic between an on-state voltage drop and turn-off time for the first time. This device can be easily made by the conventional IGBT fabrication process. An accurate and a real-time device temperature detection, as well as a high withstand capability against over-current and over-voltage conditions (short circuit immunity of 30 /spl mu/sec, clamped collector voltage of 640 V), have been achieved. Furthermore, an excellent trade-off characteristic of 1.40 V as an on-state voltage drop and of 0.18 /spl mu/sec as a fall time is also obtained.<<ETX>>

The IGBT with monolithic overvoltage protection circuit

A novel IGBT (insulated-gate bipolar transistor) with a monolithic overvoltage protection circuit has been developed to obtain high resistance to overvoltage stress. This device is characterized by novel integration of an avalanche diode with an IGBT structure. The conventional IGBT process can be used to fabricate this device without any additional photomasks. Since it exhibits a large safe operating area, this device can be applied not only to a soft switching application like a voltage resonant circuit but also to a hard switching application like a snubberless inductive load circuit.<<ETX>>

600V trench-gate IGBT with Micro-P structure

This paper describes the next generation 600V trench-gate IGBT utilizing the Micro-P structure to realize low noise and low power dissipation. We have achieved “better turn-on di/dt controllability”, “oscillation free turn-off” and “improved Von-Eoff trade-off relationship” in the 600V IGBTs. In a typical inverter operation, the new chip has realized 10% lower power dissipation and the dT<inf>j-c</inf> can be reduced by 2.5deg.C.

Current sensing IGBT structure with improved accuracy

A current sensing IGBT structure has been investigated in order to reduce collector-emitter voltage dependence of the sensing current ratio to the main IGBT current for short-circuit over-current protection. The operation physics of the current sensing IGBT during short-circuit was analyzed by numerical simulation and experimental results of the improved performance of the current sensing IGBT are presented.

Experimental and Numerical Studies on

Experimental results on the high-voltage level shifter and dV/dt robustness of 1200 V high voltage integrated circuits (HVICs) using a self-isolation (SI) structure are reported for the first time. Generally, because high dV/dt stress is applied to HVICs during insulated gate bipolar transistor (IGBT) switching, significant displacement current flows through a high-voltage isolation capacitance. This current acts as the base current of parasitic pnp and npn transistors, and causes a potential drop in their base region. In the worst case, this parasitic operation causes device destruction. In this study, not only the normal operation of HVICs but suppression of the parasitic transistors under high dV/dt condition are experimentally demonstrated by considering a high-side layout design and back diverter electrode.

dV/dt

This paper describes the next generation 1700V trench-gate FS-IGBT utilized the micro p-base structure for the first time. The new 1700V IGBT has been achieved that “better turn-on di/dt controllability”, “oscillation free turn-off” and “improved Von-Eoff trade-off relationship” as well as 600V and 1200V IGBTs. Furthermore, the critical thermal runaway temperature has successfully been elevated by the newly developed field-stop layer, which leads to increase of maximum junction temperature as high as 175 deg. C.

Robustness of 1200 V High-Voltage Integrated Circuits Using Self-Isolation Structure

The latest 6th generation (6G) IGBTs chip technology suitable for industrial motor drive applications is described in this paper. The 6G-IGBTs with micro-P structure provide better turn-on di/dt controllability, lower turn-off oscillation and better Von-Eoff trade-off relationship. By using the 6G-IGBTs with micro-P, the turn-on power dissipation can be reduced compared to the conventional IGBTs with floating p-base under the operating condition to set the same FWD reverse recovery dv/dt. The trade-off relationship between the on-state voltage drop and the turn-off power dissipation has been improved without the turn-off oscillation even in a severe condition. The impact of the micro-P structure on these characteristics has been demonstrated by using 600V and 1200V class IGBTs.

Development of the next generation 1700V trench-gate FS-IGBT

In this paper, we report an area-effective 600 V p-channel level shifter using a self-isolation structure without the degradation of blocking capability for the first time. To prevent the degradation of high-voltage isolation performance, the charge in a double reduced surface electric field (RESURF) structure is controlled at the border region between a high-voltage p-channel metal oxide semiconductor field effect transistor (MOSFET) and a high-voltage isolation region. Because of a divided p-offset region in the drift region of the high-voltage p-channel MOSFET and the high-voltage isolation region, parasitic current to the ground (GND) terminal through the isolation region can be ignored. By using the new high-voltage p-channel level shifter, a 400 V level shift operation is confirmed.

Advanced IGBT chip technology for industrial motor drive applications

This paper descr ibes IGBT and FWD design concept and measured results for the application of Magnetic Energy Recovery Switch (MERS) configuration for the first time. Since the switching frequency in the MERS application is so slow of 50–60Hz that a lower on-state voltage drop is strongly r equired for the IGBT and FWD chips even though their fast switching features are sacr ificed. Therefor e, the newly developed IGBT and FWD chip for this configuration exhibits an extr eme low on-state voltage drop while maintaining its turn-off withstand capability.