Etching process of copper

Abstract

Abstract PURPOSE:To prevent a copper thin film of lapped film pattern of chromium-lead from being overetched and to form a fine pattern with excellent reproducibility and high operability by using an etching soln. consisting of acetic acid, hydrogen peroxide and water of specified composition. CONSTITUTION:After a chromium layer 2 having about 400Angstrom and a copper layer 3 having about 5,000Angstrom are respectively vapor-deposited on a glass base plate 1 by a vacuum deposition method or the like, a master pattern 4 is formed by photoresist. The etching of the copper layer 3 is performed by using an etching soln. consisting of 5-50ml/l acetic acid, 2-50ml/l hydrogen peroxide and the balance water. By using the above-mentioned etching soln., the overetching is prevented and the pattern is formed with excellent operability. It is desirable that the self-decomposition of hydrogen peroxide due to the presence of copper ion is controlled by adding a stabilizer such as uric acid for the above-mentioned etching soln. Even if the etchig soln. is regulated to (3-4)pH by adding sulfuric acid and a pH regulating salt such as sodium acetate instead of weak acid such as acetic acid, the similar effect is obtained.

Inventors

• 👤 Haruo Tanmachi
• 👤 東夫 反町
• 👤 Toshio Matsuzaki
• 👤 松崎　壽夫
• 👤 Kiyoshi Sato
• 👤 清 佐藤
• 👤 Takumi Suzuki
• 👤 工 鈴木
• 👤 Takeshi Sugii
• 👤 岳史 椙井

Bibliographic Details