Method of pattern formation in film body

Abstract

Abstract PURPOSE:To obtain an Nb film and the like having a high accuracy by using a double layer films consisted of poly-silicon and Si3N4 to form a given opening throught the Si N layer and a larger opening than that of said Si3N4 through the poly-silicon layer availing the defference of the etching velocity with a mask. CONSTITUTION:A poly-Si 4 and an Si3N4 5 are laminated on a substrate 1 for Josephson element. After performing a resist-mask 3 on the substrate an opening 51 is set to the film 5. Then, the film 4 is etched in excess with a CF4+O2 to form an opening 41 and an Nb film 21 of a given pattern is formed by vaporizing an Nb film 2 while heating the substrate. Then, the film 4 is etched by CF4+O2. When the double film of poly-silicon and Si3N4 is used as such, the opening pertinent to the lift-off method can be obtained with accuracy. Therefore, the pattern formation of the Nb film wherein lift-off method can not be used due to the difficulty of etching and the necessity of high vaporization, can be realized with high accuracy.

Inventors

• 👤 Tadao Kato
• 👤 Yaichiro Watakabe

Bibliographic Details