Laterally diffused metal oxide semiconductor (LDMOS) structure for protecting channel district by utilizing polysilicon field polar plate

Abstract

The invention discloses an laterally diffused metal oxide semiconductor (LDMOS) structure for protecting a channel district by utilizing a polysilicon field polar plate, comprising a deep trap, a source electrode, a drain electrode, a grid electrode and the channel district, wherein the source electrode, the drain electrode, the grid electrode and the channel district are in the deep trap; the source electrode and the channel district are positioned at one side of the grid electrode; the drain electrode is positioned at the other side of the grid electrode; the doping types of the source electrode, the deep trap and the drain electrode are the same; the doping types of the source electrode, the deep trap and the channel district are opposite; and the polysilicon field polar plate is arranged above the edge of the channel district and the deep trap, or the polysilicon field polar plate is arranged above the edge of a PN junction of the channel district and the drain electrode. The LDMOS structure can reduce surface electric field between an LDMOS underway and the drain electrode so as to enhance the breakdown voltage of the LDMOS.

Description

technical field [0001] The invention relates to a semiconductor device, in particular to a high-voltage integrated circuit manufacturing device, in particular to an LDMOS (Laterally Diffused Metal Oxide Semiconductor) structure using a polysilicon field plate to protect a channel region. Background technique [0002] LDMOS (Laterally Diffused Metal Oxide Semiconductor) is a high-voltage and high-power semiconductor device, which is widely used in power integrated circuits. Currently commonly used LDMOS structures such as figure 1 with figure 2 As shown, LDMOS includes a deep well, source, drain, gate, and channel regions. The source, drain, gate, and channel regions are all in the deep well, and the source and channel regions are located on one side of the gate. side, the drain is on the other side of the gate. The source, deep well, and drain are of the same doping type, and the source, deep well, and channel region are of opposite doping types. During normal operation...

AI Technical Summary

Problems solved by technology

Since the surface electric field is relatively concentrated at the edge of the channel region away from the gate, the breakdown voltage of the channel region and the drain in this region is low, which often limits the maximum operating voltage of the device.

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