| 摘要 |
PROBLEM TO BE SOLVED: To provide a method for manufacturing a semiconductor device in LDD structure that can shorten a stage of forming a gate electrode. SOLUTION: Since the gate electrode 12d is formed in such a shape that a circumference of a substrate surface 10a is hollowed inside, a low-density impurity layer 21 can be formed inside and below the opening of the recess 12c by injecting impurity ions into a semiconductor substrate 10 through a recess 12c while using the gate electrode 12d as a mask. Further, the gate electrode 12d is formed to such a thickness that impurity ions are stopped from being transmitted when the impurity ions are injected in a high-density impurity layer forming stage, a high-density impurity layer 22 can be formed by injecting the impurity ions into the semiconductor substrate 10 while using the same gate electrode 12d as a mask. Namely, the shape of the gate electrode 12d need not be changed between the forming stages of the low-density impurity layer 21 and high-density impurity layer 22, so the electrode forming stage can be shortened. COPYRIGHT: (C)2007,JPO&INPIT
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