| 摘要 |
PURPOSE:To remarkably increase the speed of anisotripic etching by a method wherein, when a wet etching process is performed on a polysiloxin insulating film using hydrofluoric acid aqueous solution, a local exposing process and a heat treatment process are performed on the insulating film in an oxygen atmosphere using ultraviolet rays or a light containing them. CONSTITUTION:A substrate 1 is placed in a parallelled flat plate electrode plasma CVD device, a polysiloxin insulating film 2 is coated by performing a plasma polymerization using octamethyl-cyclotetrasiloxane as a monomer, and a photoresist mask 4 having a circular window 3 is provided thereon. Then, a beam of light 5, containing ultraviolet rays emitted from a low voltage mercury-arc lamp, is projected and exposed in the air, the film 2 located in the window is changed to the exposed film 6, a heat treatment is performed at 150 deg.C in an oxygen atmosphere, and the film 6 is changed to a processed film 16. Subsequently, said film 16 is removed by etching using a hydrofluoric acid aqueous solution of 1% and after a desired circular window 23, having a wide aperture on the front surface and a narrow aperture on the lower surface, has been generated below the window 3, the mask 4 is removed. |
