Semiconductor devices and methods for forming the same

A method for forming a semiconductor device, comprising:

• providing a substrate having a first conductive type;
• forming an epitaxial layer having the first conductive type on the substrate;
• forming a trench in the epitaxial layer;
• forming a first insulating layer in the trench and on a top surface of the epitaxial layer;
• forming a shield electrode and a mask layer on the first insulating layer in order;
• using the mask layer to remove a portion of the first insulating layer, wherein a top surface of the first insulating layer is higher than a top surface of the shield electrode after removing the portion of the first insulating layer;
• removing the mask layer;
• forming a second insulating layer on the first insulating layer and the shield electrode;
• forming a gate electrode on the second insulating layer;
• forming a well region having a second conductive type in the epitaxial layer, wherein the second conductive type is different from the first conductive type;
• and
• forming a heavily doped region having the first conductive type in the well region.