| 摘要 |
PURPOSE:To reduce parasitic capacitance, and to improve the degree of integration easily by forming a wiring layer onto a trench filled with an insulator. CONSTITUTION:An N<+> buried layer 11 and an N epitaxial layer 12 are superposed onto a P-type Si substrate 10, and a trench 1 reaching the substrate 10 is shaped together with isolation trenches 3 through RIE, and filled with SiO2, Si3N4, etc. The trench 1 is formed where coincident with the pattern of an Al wiring layer 2. According to the constitution, element forming regions 4 are not narrowed due to bird beaks because a selective oxidation method is not used, thus reducing parasitic capacitance, then easily improving the degree of integration.
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