Buckling and postbuckling of etching-induced wiggling in a bilayer structure with intrinsic compressive stress. (June 2018)

• Record Type: Journal Article
• Authors: Okumura, Dai; Sugiura, Junya; Tanaka, Hiro; Shibutani, Yoji
• Is Part Of: International journal of mechanical sciences. Volume 141(2018)
• Page Start: 78
• Page End: 88
• Publication Date: 2018-06
• Subjects: Wiggling -- Etching -- Bilayer structure -- Buckling -- Postbuckling -- Finite element analysis; Mechanical engineering -- Periodicals; Génie mécanique -- Périodiques; Mechanical engineering; Maschinenbau; Mechanik; Zeitschrift; Periodicals; 621.05
• DOI: 10.1016/j.ijmecsci.2018.03.032
• Languages: English
• ISSNs: 0020-7403

Abstract

Highlights: Buckling and postbuckling of etching-induced wiggling in a bilayer structure is investigated. Mask layer includes intrinsic compressive stress while unmasked layer is selectively removed. Etching process is explicitly introduced via step-by-step eigenvalue buckling analysis. In explicit modeling of etching, wiggling behavior shows completely opposite tendencies. The importance of explicit modeling of etching process is confirmed. Abstract: In this study, we investigate buckling and postbuckling of etching-induced wiggling in a bilayer structure consisting of mask and masked layers. To show effects of explicit modeling of etching process, two mask–masked ridge models with and without etching (Models w/E and w/oE) are analyzed using finite element analysis. The etching process is explicitly introduced via step-by-step eigenvalue buckling analysis. Although Model w/oE predicts a constant value of the critical wavelength of wiggling regardless of the change in ridge width, Model w/E predicts a shorter wavelength depending on the decrease in ridge width and the increase in intrinsic compressive stress in the mask layer. In postbuckling analysis, Model w/oE predicts a monotonic increase in the wiggling amplitude with the constant wavelength, whereas Model w/E predicts saturation of the wiggling amplitude owing to the decreasing wavelength. In the explicit modeling of etching process, the wiggling behavior shows completely opposite tendencies. Dimensional analysis is performed to obtain empirical equations, which are compared with an experiment. Graphicalabstract :