High voltage power device with low diffusion pipe resistance

A method for forming a high voltage semiconductor power device, comprising:

• providing a first aluminum source on an upper surface of a silicon substrate;
• providing a second aluminum source on a lower surface of the substrate;
• annealing the substrate for a first given time to drive aluminum atoms from the first and second aluminum sources into the substrate;
• removing the first and second aluminum sources from the upper and lower surfaces of the substrate;
• annealing the substrate for a second given time to homogenize aluminum concentration within the substrate after the first and second aluminum sources have been removed, where the annealing the substrate for the second given time results in out-diffusion of aluminum atoms proximate the upper and lower surfaces of the substrate;
• and
• providing compensation dopants into the substrate after annealing the substrate for the second given time to compensate the aluminum out-diffusion,
• wherein the aluminum atoms driven into the substrate define an isolation diffusion structure that extends from the upper surface to the lower surface, and
• wherein the isolation diffusion structure has a sufficiently low resistance to provide a current path between a first electrode on the upper surface of the substrate and a second electrode on the lower surface of the substrate.