Toyota Jidosha Kabushiki Kaisha

Katsuhiko Nishiwaki

Tomoyoshi Kushida

Sachiko Kawaji

Akira Kawahashi

The semiconductor device includes a gate insulation film covering inner surfaces of the first trench and the second trench, and an inner surface of an intersection, and a gate electrode provided in the first trench and the second trench, and facing the semiconductor substrate via the gate insulation film. Further, the semiconductor device includes an emitter region of an n-type provided in the semiconductor substrate, exposed on the front surface of the semiconductor substrate, being in contact with the gate insulation film in the second trench, and not being in contact with the gate insulation film provided on the inner surface of the intersection of the first trench and the second trench.

Semiconductor device

To present a semiconductor device capable of operating stably even at large current, by lessening current concentration into the corners of contact opening after switching off and suppressing local heat generation without raising the ON voltage. In an insulated gate transistor divided by P field regionand gate electrode, having N+ emitter regionand P+ emitter region, and controlling conduction between emitter and collector by voltage applied to gate electrode, the shape of contact openingcontacting emitter (N+ emitter regionand P+ emitter region) and emitter electrode is formed of curved lines at four corners. Hence, eliminating right-angle apex, hole current from the field region into the emitter electrode after switching off is prevented from concentrating at one point.

Semiconductor device having a high withstand voltage

It is intended to provide a field-effective-type semiconductor device that can let low ON-resistance and non-excessive short-circuit current go together by effectively using its channel width and prevents device from destruction. In a field-effective-type semiconductor device, a semiconductor region arranged between gate electrodeshas stripe-patterned structure consisting of an Nemitter regionand a P emitter region. The P emitter region is constituted by P channel regionof low concentration and Pemitter regionof high concentration. The Nemitter regionthe P channel regionand the Pemitter regionare in contact with the emitter electrodeThereby, a channel width X is limited to the extent that is enough for ON current under normal operation state. That is, low ON-resistance and not excessive short-circuit current can go together in the field-effective-type semiconductor device.

Field-effect-type semiconductor device

It is intended to provide a high withstand voltage field effect type semiconductor device that relaxes electric fields in a semiconductor substrate without thickening thickness of a drift region and achieves withstand-ability against high voltage without sacrificing ON-voltage, switch-OFF characteristics, and miniaturization. A field effective type semiconductor device comprises emitter regionsand gate electrodesand the like on a surface (upper surface in FIG.), a collector regionand the like on the other surface (lower surface in FIG.), wherein Nfield dispersion regionsof low impurity concentration are arranged between P body regionsfacing to gate electrodesand an N drift regionbelow P body regions. Thereby, electric field between collector and emitter is relaxed and high withstand voltage field effect type semiconductor device is realized. Another field dispersion region can be arranged between the N drift regionand Pcollector regionbelow the N drift region

High withstand voltage field effect semiconductor device with a field dispersion region

In a semiconductor device having high voltage resistance and low ON voltage characteristics, charge-storage regions (insulation layer) are formed in a drift region. Formed above the drift region are a channel region, an emitter region, trench-type gate electrodes, and an emitter electrode. Strips of the insulation layer extend in a direction intersecting a direction of extension of the gate electrodes, and form a stripe pattern. The insulation layer curbs extraction of holes into the channel region. Openings in the stripe pattern of the insulation layer form depletion layers.

Semiconductor device and process for producing the device

A semiconductor device is formed such that a contact surface between a p-type high-concentration semiconductor region and an n-type high-concentration buffer region assumes a convexo-concave shape. This makes it possible to enlarge an area of the contact surface between the p-type high-concentration semiconductor region and the n-type high-concentration buffer region. As a result, holes are injected into an n-type low-concentration drift region from the p-type high-concentration semiconductor region with higher efficiency and with a less voltage drop between the pn-junction. Thus, effects of conductivity modulation can be achieved sufficiently and the on-resistance and the voltage drop of an IGBT can be lowered.

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Toyota, Japan

Katsuhiko Nishiwaki