Patent ID: 7646064

Claim:
A semiconductor die comprising: a silicon region of a first conductivity type, the silicon region having a top surface and a bottom surface; a first well of the first conductivity type that contacts the silicon region, the first well having a top surface that contacts the top surface of the silicon region, and a bottom surface spaced apart from the bottom surface of the silicon region, the first well having a dopant concentration greater than a dopant concentration of the silicon region; and a first structure extending away from the bottom surface of the silicon region up through the silicon region to contact the first well without touching the top surface of the first well, the first structure having aluminum that contacts the silicon region and the first well, the first structure including: a first base region having a side wall and including aluminum; and a plurality of spaced-apart spikes extending away from the side wall of the first base region in all directions, and including aluminum.