LDMOS device and manufacturing method thereof

According to the LDMOS device and the manufacturing method thereof provided by the invention, the first epitaxial layer is formed in the drift region through an epitaxial growth process, so that the functional region with the conduction type opposite to that of the drift region is introduced into the drift region, the surface electric field distribution of the drift region is improved, and the breakdown voltage is improved. Therefore, the process difficulty is simplified, and the position and depth of the PN junction are easy to control. 本发明提供了一种LDMOS器件及其制造方法，通过外延生长工艺在漂移区中形成第一外延层，以在漂移区中引入与其导电类型相反的功能区，改善漂移区表面电场分布，提高击穿电压。由此，简化了工艺难度，易于对PN结位置和深度进行控制。