摘要 |
One exemplary embodiment is a semiconductor structure, that can include a semiconductor substrate of one conductivity type, having a front surface and a back surface, a first semiconductor layer disposed on the front surface of the semiconductor substrate, a second semiconductor layer disposed on a portion of the back surface of the semiconductor substrate, and a third semiconductor layer disposed on another portion of the back surface of the semiconductor substrate. Each of the second and third semiconductor layers may be compositionally graded through its depth, from substantially intrinsic at an interface with the substrate, to substantially conductive at an opposite side, and have a selected conductivity type obtained by the incorporation of one or more selected dopants.
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