Patent ID: 8686504
Filing Date: 2014-04-01
Classification: H01L

Abstract:
1. A manufacturing method of a double diffused drain metal oxide semiconductor (DDDMOS) device, comprising: providing a first conductive type substrate, wherein the DDDMOS device and a low voltage device are formed in the substrate; forming a second conductive type first well in the substrate by a process step which also forms a second well in the low voltage device; forming a first gate on the substrate, wherein the first gate has a first side and a second side opposite to each other with respect to a channel direction, and wherein part of the first well is located below part of the first gate including the first side; forming a first conductive type diffusion region in the substrate by a process step which also forms a lightly doped drain in the low voltage device, wherein at least part of the diffusion region is located outside the second side with respect to the first gate; and forming a first source and a first drain with first conductive type in the substrate outside the first side and the second side with respect to the first gate respectively, wherein the first drain and the first gate are separated by part of the diffusion region, and the first source is located in the first well.