The variation of the leakage current characteristics of W/Ta2O5/W MIM capacitors with the thickness of the bottom W electrode. (June 2016)

• Record Type: Journal Article
• Authors: Yu, D.Q.; Lau, W.S.; Wong, Hei; Feng, Xuan; Dong, Shurong; Pey, K.L.
• Is Part Of: Microelectronics and reliability. Volume 61(2016)
• Page Start: 95
• Page End: 98
• Publication Date: 2016-06
• Subjects: Ta2O5 -- Surface roughness -- Surface smoothing -- Effective Schottky barrier height; Electronic apparatus and appliances -- Reliability -- Periodicals; Miniature electronic equipment -- Periodicals; Appareils électroniques -- Fiabilité -- Périodiques; Équipement électronique miniaturisé -- Périodiques; Electronic apparatus and appliances -- Reliability; Miniature electronic equipment; Periodicals; 621.3815
• DOI: 10.1016/j.microrel.2016.02.013
• Languages: English
• ISSNs: 0026-2714

Abstract

Abstract: In this paper, we will report that the leakage current characteristics can be a function of the bottom electrode. The variation of the bottom tungsten electrode thickness can affect the leakage current characteristics of W/Ta2 O5 /W MIM capacitors mainly through two mechanisms. The first mechanism is that the Ta2 O5 CVD process can be influenced by the W bottom electrode thickness. Experimentally it was observed that the thickness of the Ta2 O5 film deposited by CVD is noticeably different for samples with different bottom W electrodes with different thicknesses. The second mechanism is that the surface roughness of the bottom W electrode increases with increasing thickness, resulting in a smaller effective Schottky barrier height. A smaller effective Schottky barrier height will lead to larger leakage current. Highlights: The leakage current characteristics can be a function of the bottom electrode of the MIM structure. The thickness of the bottom electrode affects the leakage current characteristics through two mechanisms. The thickness of the bottom W layer can affect Ta2 O5 layer CVD process. Rougher surface of the bottom W electrode can result in a smaller effective Schottky barrier height.