| 摘要 |
PURPOSE:To obtain an IC of high density by a method wherein a smooth insulated and isolated layer by the use of anode oxidization of an Al film without using photoetching. CONSTITUTION:After forming an n<+>-buried layer 2 in a p-type Si substrate 1, on which a p-epitaxial layer 3, an SiO2 layer 4 and an Si3N4 layer 5 are laminated, a groove 12 reaching the substrate 1 is provided by the reactive sputtering method while adding to it a photoresist mask 6. Then a streak is formed by etching the layers 3-1 using a liquid of nitric acid fluoride series. Next an SiO2 film 7 is provided in the groove 12 and polycrystalline-Si 8, Al 9 are vacuum-evaporated. An anode oxidized film 10 is formed on the surface of the Al 9 in the groove 12. The Al 9 on the layer 8 is isolated because of the streak and not anode-oxidized. The Al 9 and the Si layer 8 near the groove are removed by etching with the anode-oxidized film 10 as a mask. Then films 10, 9 are removed by etching and the polycrystalline Si layer 11 is epitaxially formed with the layer 8 as a core, then dielectric isolation of planar construction is completed, thus making it possible to form an IC of high density of which the reduction of the active layer is minimized in the horizontal direction. |
