Etching method

Abstract

Abstract PURPOSE:To make side etching less and to form a deep groove in high accuracy by restraining the side etching generated by dry etching with an anti-etching film formed on the side wall of an Si groove. CONSTITUTION:An etching mask 2 such as an SiO2 film or an Si3N4 film is formed on an Si substrate 1 and an Si groove 5 is formed by shallowly etching with a fluorine gas such as CF4 or SF6. The inside of the Si groove is covered with an etching resistant film and etched anisotropically to cover only the side wall of the Si groove with the etching resistant film 7. For the etching resistant film, a plasma-oxidized or deposited SiO2 film is preferably used. The process is repeated again and then the etching of Si is further carried out. The undercut can be reduced to b1 and the b1 can be made one third since the etching of Si is divided into three times.

Inventors

• 👤 Takashi Tagami
• 👤 田上　高志
• 👤 Tokuo Hisafuda
• 👤 久札　得男

Bibliographic Details