High-voltage LDMOS device based on BCD process and manufacturing process

Abstract

The invention discloses a high-voltage LDMOS device based on a BCD process and a manufacturing process. The high-voltage LDMOS device comprises a substrate, the substrate is an N-type substrate, a P-type buried layer is arranged on the N-type substrate, an N-type thin epitaxial layer is arranged on the P-type buried layer, an N-trap is arranged on one side of the N-type thin epitaxial layer, a P-type light dope top layer covered with a field oxidation layer is arranged on the side, close to polycrystalline silicon, of the N-trap, an N-type injection layer is arranged on the other side of the N-trap, the N-type injection layer extends upwards to a drain electrode, a P-trap is arranged on the other side of the N-type thin epitaxial layer, a p-type field area is arranged on the upper middle portion of the P-trap, a short-circuit N-type injection layer and a short-circuit P-type injection layer are arranged on the p-type field area, the connecting position of the short-circuit N-type injection layer and the short-circuit P-type injection layer extends upwards to a source electrode, a grid electrode oxidation layer is arranged at the connecting position of the N-trap and the P-trap, the polycrystalline silicon is arranged on the grid electrode oxidation layer, and the polycrystalline silicon is externally connected with a grid electrode. The length of a voltage withstanding area of the LDMOS device is small, and the on-resistance of the device can be greatly reduced under the condition of keeping a breakdown voltage unchanged.

Description

technical field [0001] The invention relates to a high-voltage LDMOS device and a manufacturing process, in particular to a high-voltage LDMOS device and a manufacturing process based on a BCD process. Background technique [0002] BCD is a monolithic integration process technology, which can make bipolar, CMOS and DMOS devices on the same chip, called BCD process. LDMOS is laterally diffused metal oxide semiconductor. High-voltage LDMOS devices are commonly used in high-voltage power integrated circuits. They are used to meet the requirements of high-voltage resistance and power control. They are often used in radio frequency power circuits. [0003] The substrate material of the existing high-voltage LDMOS devices based on BCD process is p-type substrate, and N-type epitaxial layer is grown on the P-type substrate, and singleresurf technology is used to improve the withstand voltage. The performance of LDMOS devices with this structure is not good. High, the on-resistance...

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Problems solved by technology

[0003] The substrate material of the existing high-voltage LDMOS devices based on BCD process is p-type substrate, and N-type epitaxial layer is grown on the P-type substrate, and singleresurf technology is used to improve the withstand voltage. The performance of LDMOS devices with this structure is not good. High, the on-resistance is large under the premise of meeting the voltage

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