Semiconductor Manufacturing International (shanghai) Corporation

Semiconductor Manufacturing International (beijing) Corporation

Jiwei He

Gangning Wang

Xianyong Pu

Guangli Yang

Shannon Pu

Mike Tang

Amy Feng

Chih-Chung Tai

Semiconductor devices having a buried layer and methods for forming the same are disclosed. In an exemplary method, a hard mask layer can be provided on a semiconductor substrate. The hard mask layer can have a plurality of through-openings. A plurality of deep trenches can be formed in the semiconductor substrate using the hard mask layer as a mask. A bottom of each of the plurality of deep trenches in the semiconductor substrate can be doped to form a plurality of heavily-doped regions. One or more of the plurality of heavily-doped regions can be connected to form the buried layer in the semiconductor substrate. There is thus no need to use an epitaxial process to form active regions. In addition, lateral isolation structures can be simultaneously formed in the semiconductor substrate.

Semiconductor device having buried layer and method for forming the same

Various embodiments provide LDMOS devices and fabrication methods. An N-type buried isolation region is provided in a P-type substrate. A P-type epitaxial layer including a first region and a second region is formed over the P-type substrate. The first region is positioned above the N-type buried isolation region, and the second region surrounds the first region. An annular groove is formed in the second region to surround the first region and to expose a surface of the N-type buried isolation region. Isolation layers are formed on both sidewalls of the annular groove. An annular conductive plug is formed in the annular groove between the isolation layers. The annular conductive plug is in contact with the N-type buried isolation region at the bottom of the annular conductive plug. A gate structure of an LDMOS transistor is formed over the first region of the P-type epitaxial layer.

LDMOS device and fabrication method

Growing community of inventors

Shanghai, China

Jiwei He