Method for manufacturing N-trench lateral dual-diffusion metal oxide semiconductor (N-LDMOS)

Abstract

The invention discloses a method for manufacturing an N-trench lateral dual-diffusion metal oxide semiconductor (N-LDMOS). The method comprises the following steps of: supplying a substrate, and forming a deep N trap on the substrate; forming isolation structures in the deep N trap; forming an N trap in a drain region of the deep N trap, and forming a P trap in a source region of the deep N trap; forming a grid on the deep N trap; performing a source and drain light doping process, and respectively forming a source light doping region and a drain light doping region in the P trap and the N trap; forming grid side walls on the side walls of the grid; and performing a source and drain heavy doping and annealing process. According to the method, the deep N trap and the N trap of a drain replace a photomask in a drift region of the conventional N-LDMOS, and the P trap in the deep N trap of a source replace the photomask in the conventional body region; and the two photomasks are eliminated during manufacturing, so that the manufacturing cost of the LDMOS device is effectively reduced on the premise that the device meets a voltage withstand requirement.

Description

technical field [0001] The invention relates to the field of integrated circuit manufacturing, in particular to a manufacturing method of N-LDMOS. Background technique [0002] Lateral double-diffused metal oxide semiconductor (LDMOS) is a lightly doped MOS device, which has very good compatibility with CMOS technology. Traditional CMOS devices usually have a symmetrical source-drain structure, while LDMOS uses an asymmetric source-drain structure to meet the needs of higher withstand voltage and relatively low on-resistance. [0003] Such as figure 1 As shown, the source region of the LDMOS is provided with a body region structure 1 , and the drain region is provided with a drift region structure 2 . The body region 1 is similar to the well region in a traditional CMOS transistor, and is mainly used to control the threshold voltage of the LDMOS; the drift region 2 is mainly used to control the withstand voltage performance of the LDMOS. According to the principle of brea...

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Problems solved by technology

[0004] In the traditional CMOS process, two additional masks are usually added to the source and drain regions to form the body region 1 and the drift region 2, so as to realize the source-drain asymmetric structure of LDMOS, but the use of the mask Leading to an increase in the manufacturing cost of LDMOS, which is not conducive to actual production implementation

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