Patent ID: 7897445
Filing Date: 2011-03-01
Classification: H01L

Abstract:
1. A method of forming a semiconductor device, comprising the steps of: providing a semiconductor layer; providing a first masking layer over the semiconductor layer, said first masking layer comprising a material that provide a permeable barrier to a dopant; providing a second masking layer over the first masking layer, wherein the second masking layer is a conductive layer; sequentially dry etching the conductive layer and the first masking layer such that sidewalls of the first masking layer and the conductive layer are aligned with each other; etching the conductive layer into a trapezoid profile to expose a portion of the first masking layer covering a first region of the semiconductor layer; and exposing the semiconductor layer, including the first region covered by the first masking layer, to the dopant, wherein the first region covered by the first masking layer is lightly doped with the dopant in comparison to a second region not covered by the first masking layer.