Semiconductor device and manufacturing method thereof

Abstract

The invention provides a semiconductor device and a manufacturing method thereof, and the method comprises the steps: providing a PDSOI substrate with a first device region and a second device region, and the PDSOI substrate comprises a lower substrate, an insulating buried layer and a semiconductor layer from bottom to top; forming an epitaxial layer on the semiconductor layer of the second device region; forming an MOS (Metal Oxide Semiconductor) transistor in the first device region and forming an LDMOS (Laterally Diffused Metal Oxide Semiconductor) transistor in the second device region. According to the invention, the breakdown voltage of the LDMOS transistor can be improved.

Description

technical field [0001] The invention relates to the field of semiconductor integrated circuit manufacturing, in particular to a semiconductor device and a manufacturing method thereof. Background technique [0002] The semiconductor-on-insulator (SOI) structure includes a lower substrate, an insulating buried layer and an upper semiconductor layer. The SOI substrate is divided into partially depleted SOI (Partially-Depleted Semiconductor-On-Insulator, PDSOI) and fully depleted according to whether the active region is depleted. Depleted SOI (Fully-Depleted Semiconductor-On-Insulator, FDSOI), generally speaking, the upper semiconductor layer of the FDSOI substrate will be relatively thin, and the cost of the substrate is relatively high. On the other hand, the threshold voltage of FDSOI is not easy to control. The PDSOI substrate is still used, wherein the thickness of the upper semiconductor layer of the PDSOI substrate purchased from the manufacturer is equal, but in the pr...

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Problems solved by technology

[0002] The semiconductor-on-insulator (SOI) structure includes a lower substrate, an insulating buried layer and an upper semiconductor layer. The SOI substrate is divided into partially depleted SOI (Partially-Depleted Semiconductor-On-Insulator, PDSOI) and fully depleted according to whether the active region is depleted. Depleted SOI (Fully-Depleted Semiconductor-On-Insulator, FDSOI), generally speaking, the upper semiconductor layer of the FDSOI substrate will be relatively thin, and the cost of the substrate is relatively high. On the other hand, the threshold voltage of FDSOI is not easy to control. The PDSOI substrate is still used, wherein the thickness of the upper semiconductor layer of the PDSOI substrate purchased from the manufacturer is equal, but in the process of manufacturing semiconductor devices, different devices may need to be fabricated on the same substrate. Different devices have different requirements for breakdown voltage, and the use of upper semiconductor layers with equal thickness cannot meet the requirements of different devices for breakdown voltage at the same time.

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