Taiga Arai

A Planar-Gate High-Conductivity IGBT (HiGT) With Hole-Barrier Layer

A high-conductivity insulated gate bipolar transistor (IGBT) (HiGT) with a double diffused MOS structure and an n-type hole-barrier layer surrounding a p-layer (planar HiGT) is presented. The hole-barrier layer prevents the holes from flowing into the p-layer and stores them in the n-layer. The planar HiGT provides a better tradeoff between collector-emitter saturation voltage [VcE(sat)] and turn-off loss than conventional IGBTs, regardless of the injection efficiency of the p-layer on the collector side, while it maintains a high blocking voltage by controlling the sheet carrier concentration of the hole-barrier layer. The planar HiGT has a tough short-circuit capability of more than 10 mus at 125degC, with a saturation current similar to that of conventional IGBTs.

1.7kV trench IGBT with deep and separate floating p-layer designed for low loss, low EMI noise, and high reliability

A novel 1.7kV IGBT with deep floating-p layers separated from trench gates has been developed to realize low loss, low EMI noise, and high reliability. Separating floating-p layers from the trench gates reduces excess V<inf>GE</inf> overshoot, which results in a 51% smaller reverse recovery dV<inf>AK</inf>/dt than the conventional IGBT. The deep floating p-layers weaken the electric field under the trenches, which results in an avalanche breakdown voltage of 2250V. In addition, the E<inf>on</inf> + E<inf>off</inf> for the proposed structure can be reduced by 47% more than that of the conventional one, maintaining a low V<inf>CE(sat)</inf> of 2.3V at 125°C.

Novel 3.3-kV advanced trench HiGT with low loss and low dv/dt noise

Novel 3.3-kV trench IGBT with low loss and low dv_AK/dt noise was developed. The structural feature of the IGBTs is deep p-WELL layers separated from trench gates. This structure suppresses excess V_GE overshoot and then reduces recovery dv_AK/dt. Moreover, this effect is enhanced by reducing the resistance of the deep p-WELL layers (R_FP). It was found that, for the first time, the trade-off characteristics between V_CEsat and recovery dv_AK/dt were drastically improved by separating p-WELL layers from trench gates and decreasing R_FP. The recovery dv_AK/dt could be reduced by 79% more than that for the conventional trench IGBT, maintaining a small V_CEsat and E_on equal to the conventional one.

Side gate HiGT with low dv/dt noise and low loss

This paper presents a novel side gate HiGT (High-conductivity IGBT) that incorporates historical changes of gate structures for planar and trench gate IGBTs. Side gate HiGT has a side-wall gate, and the opposite side of channel region for side-wall gate is covered by a thick oxide layer to reduce Miller capacitance (Cres). In addition, side gate HiGT has no floating p-layer, which causes the excess Vge overshoot. The proposed side gate HiGT has 75% smaller Cres than the conventional trench gate IGBT. The excess Vge overshoot during turn-on is effectively suppressed, and Eon + Err can be reduced by 34% at the same diodes recovery dv/dt. Furthermore, side gate HiGT has sufficiently rugged RBSOA and SCSOA.

New low-resistance and compact MOSFETs for analog switch ICs with V-groove dielectric isolation

A low-resistance and compact MOSFET for analog switch ICs with Dielectric Isolation (DI) process technology is proposed. To obtain a high current density, we have developed new MOSFET with internal prominence, which reduce the drift resistance of devices with a high breakdown voltage. New N-ch and P-ch compact MOSFETs for level shifters have also been developed that can control saturation current with a low electric field under the gate region by using a junction field effect transistor structure for higher hot carrier reliability. The areas of these MOSFETs can be shrunk about 40% in 220-V devices.

High power density side-gate HiGT modules with sintered Cu having superior high-temperature reliability to sintered Ag

In this study, sintered Cu is shown to have superior reliability to that of sintered Ag, in a high-temperature thermal cycle test up to 200°C and superior power cycle durability at a maximum junction temperature of 175°C. A 1700 V low-stray-inductance dual module made with sintered Cu and a leading-edge side-gate HiGT (High-conductivity IGBT) is also shown to have high power density with low loss and ten times higher power cycle durability compared with Pb-rich solder.