Patent ID: 7566951

Claim:
A silicon structure having a central axis, a front surface and a back surface that are generally perpendicular to the central axis, a central plane between and parallel to the front and back surfaces, a circumferential edge, and a radius extending from the central axis to the circumferential edge, wherein the structure further comprises: a near-surface region extending substantially from the central axis to the circumferential edge and a distance, D 1 , of between about 0.5 μm and about 25 μm from the front surface toward the central plane, a transition region extending substantially from the central axis to the circumferential edge and a distance, D 2 , of less than about 1 μm from the near-surface region toward the central plane, a bulk region extending substantially from the central axis to the circumferential edge and a distance, D 3 , of greater than about 5 μm from the transition region toward the central plane, wherein the bulk and near-surface regions are doped with a dopant, the concentration of dopant in the near-surface region is at least 10 times the maximum concentration, c, of dopant in the bulk region, and c is greater than about 5×10 13 atoms/cm 3 .