Dry etching

Abstract

Abstract PURPOSE:To enable the etching process having extremely excellent selectivity to be performed by a method wherein a mixed gas comprising the first gas containing bromine atoms and the second gas containing oxygen atoms and not containing carbon atoms is used as a reactive gas. CONSTITUTION:A thermal oxide film 21 1000Angstrom thick is formed on the surface of a silicon substrate 20; a silicon nitride film 22 4000Angstrom thick is formed on the film 21; and positive type resist patterns R are formed on the surface of the film 22. This specimen 36 is mounted on a cathode 32, after evacuating the dryetching device through a gas exhaust port 37, hydrogen bromide is led-in as an etching gas at 20 SCCM simultaneous with the introduction of oxygen at 5 SCCM (not to contain carbon) while the whole surface is impressed with 0.4W/cm<2> of high-frequency power per unit space of anode in the state at the pressure of 0.1Torr to produce plasma for performing the etching process. Through these procedures, the silicon nitride film 22 having extremely excellent selectivity is etched away while the silicon oxide film 21 is left in excellent state without being etched away.

Inventors

• 👤 Tsunetoshi Arikado
• 👤 経敏 有門
• 👤 Haruo Okano
• 👤 晴雄 岡野

Bibliographic Details