Ion beam etching process for high-density spintronic devices and its damage recovery by the oxygen showering post-treatment process. (21st March 2017)

• Record Type: Journal Article
• Authors: Jeong, Junho; Endoh, Tetsuo
• Is Part Of: Japanese journal of applied physics. Volume 56:Number 4(2017)Supplement
• Publication Date: 2017-03-21
• Subjects: Physics -- Periodicals; 621.05
• DOI: 10.7567/JJAP.56.04CE09
• Languages: English
• ISSNs: 0021-4922

Abstract

Abstract: The electric short fail trend of the perpendicular magnetic tunnel junctions (p-MTJs) caused by the ion beam etching (IBE) process is studied at various ion beam angles and cell-to-cell space widths. The number of electric short fails increases markedly at an ion beam angle greater than 35° and a cell-to-cell space width less than 30 nm at the assumed MTJ height including a hard mask (HM) of 20 nm. In order to recover these electric short fails, we propose the selective oxidation process called the oxygen showering post-treatment (OSP). By the OSP process, the number of electric short fails in sub-30-nm-spaced MTJ arrays is reduced from 25 to 0.8%, and the magnetoresistance (MR) is increased from 99 to 120%. By this result, we can verify that the damaged layer is recovered successfully by the OSP, and that the OSP can be a universal post-treatment process even beyond the 20 nm design rule for use in both reactive ion etching and IBE schemes.