| 摘要 |
PURPOSE:To highly integrate an element by forming a film pattern which is smaller than a mask material pattern by side etching, thereby forming an ultrafine element isolating film. CONSTITUTION:A polycrystalline silicon film is accumulated on a thermally oxidized film 2 on the surface of a silicon substrate 1, isotropically etched, then side etching occurs, and a polycrystalline silicon film pattern 3' which is smaller than a photoresist pattern 4 is formed. An aluminum film 5 is deposited, the pattern 4 is removed, and an aluminum film pattern 5' is formed on the film 2. A slot 6 is formed in the substrate 1 by anisotropic etching, a BSG film is accumulated, etching back by anisotropic etching to bury part of the BSG film in the slot 6, thereby forming an element isolating film 8. The thickness of the polycrystalline silicon film becomes substantially equal to the width of the film 8, and the width of the film 8 can be controlled by the thickness of the silicon film. |
