Semiconductor device and manufacturing method thereof

Abstract

The invention provides a semiconductor device and a manufacturing method thereof. The semiconductor device comprises a first-class high-voltage nLDMOS device, a first-class high-voltage pLDMOS device,a second-class high-voltage nLDMOS device, a second-class high-voltage pLDMOS device, a low-voltage NMOS device, a low-voltage PMOS device and a low-voltage NPN device which are integrated on the same chip. The first p-type field reduction layer is located on the surface, so that the conductive channel moves downwards, the hot carrier effect is reduced, and the reliability of the device is improved. The n-type heavily doped layer, the p-type field reduction layer, the n-type deep trap, the p-type trap and the p-type substrate form a multiple RESURF structure, the specific on-resistance of thehigh-voltage device is reduced, and the manufacturing cost of the chip is reduced. Compared with a traditional structure without an n-type heavily doped layer, the n-type heavily doped layer has smaller on-resistance under the condition of the same chip area, the on-resistance and the dynamic resistance of the device can be reduced through the n-type heavily doped layer, and the nLDMOS device further has the advantages of being high in input impedance, low in output impedance and the like.

Description

technical field [0001] The invention belongs to the technical field of semiconductor power devices. In particular, a semiconductor device and its manufacturing method. Background technique [0002] The development of high-voltage power integrated circuits is inseparable from high-voltage and low-voltage semiconductor devices. High-voltage power integrated circuits often use the high analog precision of Bipolar transistors, the high integration of CMOS, and the high power or voltage characteristics of DMOS (Double-diffused MOSFET) to integrate Bipolar analog circuits, CMOS logic circuits, CMOS analog circuits and DMOS high-voltage power devices. Monolithically integrated together (referred to as BCD device). Lateral high-voltage devices are widely used in high-voltage power integrated circuits because they are easy to integrate with low-voltage signal circuits through internal connections because the gates and gates are all on the chip surface. However, due to the existenc...

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Problems solved by technology

However, due to the Ron∝BV2.3~2.6 relationship between the on-resistance Ron of the DMOS device and the device withstand voltage BV, the on-resistance of the device rises sharply when the device is used in high voltage, which limits the lateral high voltage. Application of DMOS devices in high-voltage power integrated circuits, especially in circuits requiring low conduction loss and small chip area

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