Manufacturing method of P-LDMOS (P-Laterally Diffused Metal Oxide Semiconductor)

Abstract

The invention discloses a manufacturing method of a P-LDMOS (P-Laterally Diffused Metal Oxide Semiconductor), comprising the steps that: a substrate is provided, and a deep N trap is formed on the substrate; a separation structure is formed in the deep N trap; a P trap is formed in the drain zone of the deep N trap, and an N trap is formed in the source zone of the deep N trap; a grid electrode is formed on the deep N trap; a source-drain light dope technique is performed, and a source light dope zone and a drain light dope zone are respectively formed in the N trap and the P trap; and a grid electrode side wall is formed on the side wall of the grid electrode, and a source-drain heavy dope technique and an annealing technique are performed. According to the manufacturing method, the deep N trap and the P trap in the drain are adopted to replace a photo-mask in a drifting zone of a conventional P-LDMOS, the N trap in the deep N trap in the source is adopted to replace a photo-mask in a conventional body zone, two photo-masks in the processing are omitted, and the manufacturing cost of an LDMOS device is effectively reduced on the premise that the pressure resistance of the device is met.

Description

technical field [0001] The invention relates to the field of integrated circuit manufacturing, in particular to a P-LDMOS manufacturing method. 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 breakdo...

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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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