公开(公告)号：US11309406B2

公开(公告)日：2022-04-19

申请号：US16770362

申请日：2018-12-05

Applicant: CSMC TECHNOLOGIES FAB2 CO., LTD.

Inventor： Nailong He ,  Sen Zhang ,  Guangsheng Zhang ,  Yun Lan

IPC: H01L29/66 ,  H01L21/762 ,  H01L29/417 ,  H01L21/033 ,  H01L29/06 ,  H01L29/78 ,  H01L29/423

Abstract: A manufacturing method of an LDMOS device comprises: obtaining a wafer formed with a doped region having a first conductivity type, wherein a top buried layer is formed inside the doped region having the first conductivity type, and a field oxide insulation layer structure is formed on the top buried layer; disposing a trench on the doped region having the first conductivity type, wherein the trench extends to the top buried layer and the field oxide insulation layer structure such that a portion of the top buried layer is removed; injecting an ion of a second conductivity type to form a well region below the trench; and forming a doped source region in the well region. The first conductivity type and the second conductivity type are opposite conductivity types.