| 摘要 |
PURPOSE:To enable the uniformity of a thermal oxide SiO2 film coating the substrate by covering a groove, by a method wherein a groove is formed in a semiconductor substrate by anisotropic etching with the mask of a corrosion- resistant film; then, the substrate edge at the groove aperture is removed byu photoreacting etching. CONSTITUTION:The P-type Si substrate 1 with a surface index 100 is coated with a thermal oxide SiO2 film 2 of 300nm thickness as the corrosion-resistant film. Next, a region where a groove is to be formed is opened by RIE by a normal photolithographic process, and the remaining SiO2 film 2 is masked and subjected to anisotropic etching that etches only in a vertical direction, resulting in the formation of a groove 3 in the substrate 1. On photoreacting etching that follows Si RIE, an oblique cut 6 is formed by the difference in etching rate of the crystal orientation. The SiO2 film 2 is removed with HF, and the substrate 1 is thinly coated with a thermal oxide SiO2 film 4 by cover ing the inner surface of the groove 3 as the insulation film. The whole surface of the substrate is coated with poly Si by CVD, which is then patterned into a capacitor opposition electrode 5. |
