Patent ID: 6930027

Claim:
A method of manufacturing a semiconductor component, the method comprising: providing a semiconductor substrate having an upper surface; forming a first electrically insulating layer over the upper surface; forming a second electrically insulating layer over the first electrically insulating layer; etching a first trench and a second trench through the second electrically insulating layer and the first electrically insulating layer and into the semiconductor substrate, wherein the second trench comprises a bottom surface; etching a third trench through the bottom surface of the second trench and into the semiconductor substrate, wherein the third trench has a first portion and a second portion interior to the first portion; forming a third electrically insulating layer over the second electrically insulating layer, in the first portion of the third trench, and in the first trench, without filling the second portion of the third trench; and forming a plug layer in the second portion of the third trench, wherein: forming the plug layer comprises etching the layer to form a top surface of the plug layer below the bottom surface of the second trench.