Patent ID: 7307316
Filing Date: 2007-12-11
Classification: H01L

Abstract:
1. A liquid crystal display device, comprising: a substrate; a buffer layer formed on the substrate; a semiconductor layer formed on the buffer layer; a gate insulating layer formed on the semiconductor layer; a gate electrode formed on the gate insulating layer; source/drain regions formed by implanting a first dopant into the semiconductor layer with the gate electrode serving as a mask; a first lightly doped region formed by implanting a second dopant into the semiconductor layer with the gate electrode serving as a mask, wherein the first lightly doped region extends to a position underlying the gate electrode; a second lightly doped region formed by implanting a third dopant into the semiconductor layer with the gate electrode serving as a mask, wherein the second lightly doped region extends to a position underlying the gate electrode; a third lightly doped region formed by implanting a fourth dopant into the semiconductor layer with the gate electrode serving as a mask, wherein the third lightly doped region surrounds the first lightly doped region and one of the source/drain regions, and wherein the third lightly doped region extends to a position underlying the gate electrode; and a fourth lightly doped region formed by implanting a fifth dopant into the semiconductor layer with the gate electrode serving as a mask, wherein the fourth lightly doped region surrounds the second lightly doped region and one of the source/drain regions, and wherein the fourth lightly doped region extends to a position underlying the gate electrode.