| 摘要 |
PURPOSE:To increase the gate electrode of a MISFET of a memory cell in crosssectional area, to decrease a word line in resistance, and to enable a semiconductor memory device of this design to operate at a high speed by a method wherein the gate electrode of the MISFET buried inside the part of a fine groove larger in width is formed nearly square in cross section. CONSTITUTION:The whole surface of a polycrystalline silicon film 13A is anisotropically etched so far as the thickness of the deposited silicon film 13A to form a gate electrode 13 buried in a fine groove 2B. A buried electrode 13 is formed between an active island region 3 and an isolating protrudent belt 10 inside a fine groove 2A. By this constitution, the gate electrodes 13 can be buried in the fine grooves 2A and 2B, which surround the active island regions 3, in a self-aligned manner to the active island regions 3, a word line can be formed of the gate electrodes 13, and the gate electrode 13 inside the fine groove 2A is formed in a square in cross section to increase in crosssectional area, whereby the word line 13 can be decease in resistance. |
