Device for eliminating high electric field

Abstract

The invention provides a device for eliminating a high electric field. A cellular structure comprises a substrate, a source contact electrode, a drain contact electrode, a grid electrode, a grid oxide layer, a second type drift region, a second type bar, a first type bar, a second type buffer region, a first type well region, a second type heavy-doped region, a first type heavy-doped region and a third type heavy-doped region. According to the device for eliminating the high electric field, the left end of the second type bar extends into the first type well and is not connected with the second type heavy-doped region; the right end of the first type bar extends into the second type buffer region, so that the second type bar at the left end is exhausted by a multi-surface first type impurity, and the first type bar at the right end is exhausted by a multi-surface second type impurity; therefore, the peak of an electric field at a super junction edge is weakened, in-advance breakdown of the device is avoided, and the breakdown voltage of a super junction device is further increased; and the left side of the second type bar extends into the first type well region, so that the channel resistance of the device in an on state is reduced, and the specific on-state resistance of the device is reduced.

Description

technical field [0001] The invention belongs to the technical field of semiconductor power devices, and in particular relates to a device for eliminating high electric fields. Background technique [0002] The development of modern power electronics technology requires power devices to have superior high-voltage, high-speed, and low-power performance. In order to meet high withstand voltage, traditional power MOSFETs need to reduce the concentration of the drift region or increase the length of the drift region, but this approach will make the conduction The resistance also increases accordingly. Therefore, in traditional power device applications, on-resistance and breakdown voltage are contradictory, and the limit relationship between them is R on ∝BV 2.5 . Superjunction (SJ) devices, as a new type of power device, have the advantage of greatly reducing the specific on-resistance of the device while keeping the withstand voltage of the device basically unchanged. In su...

AI Technical Summary

Problems solved by technology

However, in actual device manufacturing, due to various reasons, the charge imbalance between P and N bars is easy to generate a high electric field, especially at the edge of the superjunction structure, which causes premature breakdown of the device and affects the withstand voltage of the device.

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