| 摘要 |
PURPOSE:To form a stable insulating film with a desired tapered angle simply, and to prevent a defective breaking at a step part of a metallic wiring by forming at least two oxide insulating layers under different conditions on manufacture and utilizing the difference of the etching rates of these oxide insulating layers. CONSTITUTION:A thermal oxide film 2 is formed on a silicon substrate 1 in approximately 5,000Angstrom , and an LPCVD oxide film 3 is formed on the thermal oxide film 2 in 5,000Angstrom at approximately 0.6Torr pressure and a growth temperature of 850-950 deg.C by using S1H2Cl2 and N2O gas. The thermal oxide film 2 and the LPCVD oxide film 3 are etched selectively while using a photo-resist as a mask through a photoetching method. A wet type etching method by a substance such as hydrogen fluoride is used for etching. Accordingly, a tapered angle of 10 deg. is formed to the thermal oxide film 2 while a tapered angle of 45 deg. is formed to the LPCVD oxide film 3 as a sectional shape after etching. |
