Patent ID: 6946389

Claim:
A method comprising: forming at least one first trench within a semiconductor substrate at a first depth; depositing a first conductive material, which has a melting point high enough to prevent unwanted metallurgical changes during subsequent processing, substantially at the bottom of each first trench; forming at least one second trench within the semiconductor substrate at a second depth shallower than the first depth; depositing a second conductive material, which has a melting point high enough to prevent unwanted metallurgical changes during subsequent processing, substantially at the bottom of each second trench; surrounding the first conductive material and the second conductive material with an insulative material to prevent short circuiting between the first conductive material and the second conductive material and to provide electrical insulation between the first and second conductive materials and the semiconductor substrate; and connecting the first conductive material to conductive parts that extend upwardly on opposite sides of the second conductive material beyond the second depth.