Semiconductor structure and forming method thereof

Abstract

The invention provides a semiconductor structure and a forming method thereof. The forming method comprises the steps that a semiconductor substrate is provided, and a body region is formed in the semiconductor substrate; a drift region is formed in the body region, and the doping type of the drift region is opposite to that of the body region; a channel region is formed in the body region, the part of the channel region extends in the direction where the drift region is located to form at least one channel extension region, the channel extension regions and the drift region are distributed inan interdigital shape, and the doping type of the channel region is identical to that of the body region; an isolation region is formed in the drift region, and the end portions of the channel extension regions are located below the isolation region; a grid structure is formed on the surface of the semiconductor substrate; a source region is formed in the channel region at one side of the grid structure, and a drain region is formed in the drift region and located at the side, away from the channel region, of the isolation region.

Description

[0001] This application is a divisional application with the application number 2015100782107, the application date of February 13, 2015, and the title of the invention "semiconductor structure and its formation method". technical field [0002] The invention relates to the field of semiconductor manufacturing, and in particular to a semiconductor structure and a forming method thereof. Background technique [0003] Lateral double diffused metal oxide semiconductor (LDMOS) device is a lightly doped MOS device, which has very good compatibility with CMOS process, and has good thermal stability and frequency stability, high gain and durability, Low feedback capacitance and resistance, widely used in RF circuits. [0004] In the BCD process, a P-type LDMOS device whose drain end can withstand high voltage is usually required. In the prior art, the structure of a conventional P-type LDMOS device is as figure 1 with figure 2 As shown, it includes: a semiconductor substrate 10...

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Problems solved by technology

[0006] In order to overcome the problem of low breakdown voltage of existing LDMOS devices, the present invention provides a semiconductor structure with high breakdown voltage and its forming method

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