Isolated NLDMOS device and manufacturing method thereof

Abstract

The invention discloses an isolated NLDMOS device. A first deep trap ion implantation region, a plurality of second deep trap ion implantation regions and a P-type trap are formed on a P-type semiconductor substrate; a first space is formed between the first deep trap ion implantation region and a second deep trap ion implantation region closest to a drain region; the first deep trap ion implantation region and each second deep trap ion implantation region are integrally communicated after thermal propulsion and form an N-type deep trap; the N-type deep well between the second side surface of the P-type well and the drain region forms a drift region; a second space is formed between the second deep trap ion implantation regions, and the P-type trap is surrounded by an integral structure formed by the second deep trap ion implantation regions; and by setting the second space, the influence of the N-type deep well on the P-type concentration of the P-type trap is reduced, and the P-type net doping concentration of the P-type trap is increased. The invention further discloses a manufacturing method of the isolation type NLDMOS device. According to the invention, the breakdown voltage of the device can be improved, and meanwhile, a good isolation effect between the body region and the semiconductor substrate is ensured.

Description

technical field [0001] The invention relates to the field of manufacturing semiconductor integrated circuits, in particular to an isolated NLDMOS device; the invention also relates to a manufacturing method of the isolated NLDMOS device. Background technique [0002] In conventional non-isolated NLDMOS, there is no isolation structure between the body region (body) composed of P-type wells and the P-type semiconductor substrate, so that the body region and the source region composed of N+ regions formed in the body region can only be connected to the same potential as the semiconductor substrate, that is, 0V potential. NLDMOS means N-type LDMOS. [0003] N-type deep well isolation is used between the body region of the isolated NLDMOS and the P-type semiconductor substrate, so that the body region and the source region can be connected to a voltage different from that of the semiconductor substrate, so that the body region and the source region can be at 0V potential and F...

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Problems solved by technology

figure 1 In the existing structure shown, the second deep well ion implantation region 202b directly surrounds the P-type well 204, which will reduce the P-type net doping concentration of the P-type well 204, that is, will make the drift region The concentration relative to the P-type well 204 will be relatively thick, thereby reducing the depletion ability of the drift region, and finally reducing the breakdown voltage of the device

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