| 摘要 |
PURPOSE:To obtain a short channel MOSFET easily by a method wherein an insulating film is laminated onto the surface of a trench formed on a semiconductor substrate, a conductive film is laminated onto the insulating film, a resist is applied, a gate electrode is formed only in the trench through etchback without using a mask, and impurity ions are implanted to the whole surface to form source and drain regions. CONSTITUTION:A polysilicon film 22 as a conductive film for a gate electrode and a resist 23 are applied onto the whole surface of an silicon substrate 11 to which a trench is shaped, the gate electrode 13 is formed only into the trench 21 without employing a mask through etching under conductions in which the etching rates of both the film 22 are the resist 23 are equalized, and the surface of an element can be flattened. Ions are implanted to the whole surface without using the mask when shaping source-drain region 15, thus simultaneously allowing the formation of the source-drain regions 15 and the lowering of the resistance of the gate electrode 13 consisting of polysilicon, etc. Accordingly, an excellent buried gate type MOSFET having short channel length is acquired easily.
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