| 摘要 |
PURPOSE:To obtain an element forming region of accurate size by coating the whole surface with a thin insulating film, forming an Al-Cu alloy film, Cu concentration therein is specified, onto the element forming region, thinning the lower end of the alloy film through etching and removing the exposed section of the insulating film while using the lower end as a mask when the insulating for isolating an element is formed to a semiconductor substrate. CONSTITUTION:An SiO2 film 12 and an Al-Cu alloy film 13 are laminated and applied on an Si substrate 11, and the exposed section of the film 13 is removed through reactive ion etching while using a resist film 14 as a mask to expose the film 12. In the constitution, Cu concentration in the film 13 is made a little less than 2% in a surface section, increased gradually with the deepening of depth and reduced suddenly, and increased with an approach to the boundary of the film 12 up to approximately 8%. Accordingly, the lower end of the residual film 13 is brought to the state of overhang, and the film 12 on both sides of the lower end and the surface layer section of the substrate 11 are removed while using the lower end as a mask. An SiO2 film 15 is formed to the surface layer section of the substrate 11, and a groove 16 in extremely narrow width is shaped between the film 15 and the residual film 12. |
