Patent ID: 8778764
Filing Date: 2014-07-15
Classification: H01L

Abstract:
1. A method for making an insulated gate semiconductor device having a shield electrode structure comprising: providing a region of semiconductor material having a major surface; forming a first trench extending from the major surface into the region of semiconductor material; forming a dielectric structure along surfaces of the first trench, the dielectric structure comprising a first dielectric layer along surfaces of the first trench and a second dielectric layer overlying the first dielectric layer; removing portions of the first and second dielectric layers along a lower surface of the first trench; forming a second trench extending from the first trench into the region of semiconductor material; forming a third dielectric layer along surfaces of the second trench, wherein the third dielectric layer is thicker than the dielectric structure; forming a shield electrode within the second trench along the third dielectric layer and within a portion of the first trench along a portion of the dielectric structure, wherein the shield electrode has a wide portion adjacent the dielectric structure and a narrow portion adjacent the third dielectric layer; removing a portion of the second dielectric layer after forming the shield electrode, wherein another portion of the second dielectric layer remains between the wide portion and the first dielectric layer; forming an inter-electrode dielectric layer overlying the wide portion; forming a gate electrode overlying the inter-electrode dielectric layer; and forming a body region within the region of semiconductor material, wherein the body region and the first trench are adjacent.