Patent ID: 9287394
Filing Date: 2016-03-15
CPC Classification: H01L

Claim Text:
1. A manufacturing method of a lateral double diffused metal oxide semiconductor (LDMOS) device, comprising: providing a substrate with a first conductive type; forming with a second conductive type a drift region on the substrate; forming an isolation oxide region on the drift region to define an operation region, wherein the operation region is located in the drift region; forming an oxide region on the drift region in the operation region having a first thickness by same process steps which form the isolation oxide region; defining a second oxide region in the oxide region by a mask layer; forming the second oxide region in the oxide region having a second thickness by an etching process, wherein a first oxide region is formed, which is a remaining not-etched portion of the oxide region, wherein the second oxide region is directly connected to the first oxide region in a lateral direction, wherein the second thickness is less than the first thickness; removing the mask layer; forming a gate on the drift region in the operation region, which overlays at least part of the second oxide region and part of the first oxide region, including: forming a body region with a first conductive type in the drift region, and part of the body region is beneath the gate; forming a source with the second conductive type in the body region, wherein the spacer layer is located between the source and the stack layer from a top view; and forming a drain with the second conductive type in the drift region, which is located between the first oxide region and the isolation oxide region; wherein the first oxide region, the second oxide region, and the isolation oxide region are local oxidation of silicon (LOCOS) structures; wherein the isolation oxide region, the drain, the first oxide region, the second oxide region, and the dielectric layer are sequentially connected in the lateral direction.