Minute cavity formation manner and possesses the minute cavity the minute device

摘要

PURPOSE: To form a minute cavity with excellent controllability in a silicon substrate by etching the substrate through minute holes included in the specified region of a porous film, forming the cavity beneath the specified region, and forming an upper film layer so as to cover the minute holes on the porous film. ;CONSTITUTION: A specified opening 4 is provided in a resist film 3, which is formed on the surface of SiO₂ on the surface of a silicon substrate 1. Then with the resist film 3 as a mask, the SiO₂ film is selectively etched by RIE. The surface of the silicon substrate 1 at the bottom surface of the opening 4 is exposed. Then, the resist film 3 is removed. The substrate is cleaned, and a natural oxide film 5 is formed at the exposed part of the surface of the silicon substrate 1. Then, ultraviolet rays are cast in a chlorine atmosphere. A cavity 6, which is covered with the natural oxide film 5 having many minute holes, is formed in the island shape at the lower part of the opening 4. When an SiO₂ film 7 is deposited on the surface of the substrate, the cavity, which is tightly closed with the SiO₂ film 7, is formed.;COPYRIGHT: (C)1995,JPO