Manufacturing method of soi high-voltage power device

Abstract

The present invention relates to a manufacturing method of SOI devices, and in particular, to a manufacturing method of SOI high-voltage power devices. The method comprises steps of: forming a first oxide layer in a section on the surface of the SOI substrate; removing the first oxide layer to form a depressed area in the corresponding section of the upper surface of the SOI substrate; forming a second oxide layer, the upper surface of which is as high as the that of the SOI substrate, in the depressed area formed in step (B); performing photoetching and doping processes to form a P-type region, an N-type region and a gate region on the thus-formed structure where the second oxide layer is formed; forming a third oxide layer by deposition on the drift region of the structure after P-type and N-type regions are formed; wherein the total thickness of the third oxide layer and the second oxide layer approximates to the thickness of the buried oxide layer in the SOI substrate; and forming metal sub-regions, which are respectively in contact with the P-type region, the N-type region and the gate region, on the structure where the third oxide layer is formed, thereby forming a high-voltage power device.