title: A new method for the characterization of micro-/nano-periodic structures based on microscopic Moiré fringes.
abstract: Linewidth and opening ratio (ratio of linewidth to period) are important parameters in characterizing micro-/nano-periodic and quasi-periodic structures. Periodic structures are conventionally characterized by the direct observation of specimens under a microscope. However, the field of view is relatively small, and only certain details can be acquired under a microscope. Moreover, the non-uniformity of the linewidth in quasi-periodic structures cannot be detected. This paper proposes a new characterization method for determining the linewidth and opening ratio of periodic structures based on Moiré fringe analysis. This method has the advantage of full-field characterization of the linewidth of micro-/nano-structures over a larger area than that afforded by direct observation. To validate the method, the linewidth of scanning electron microscope (SEM) scan lines was first calibrated with a standard grating. Next, a microperiodic structure with known geometry was characterized using this calibrated SEM system. The results indicate that the proposed method is simple and effective, indicating a potential approach for the characterization of gratings over large areas. This technique can be extended to various high-power scanning microscopes to characterize micro-/nano-structures.
authors.affiliation: AML, Department of Engineering Mechanics, Tsinghua University, Beijing 100084, China.
authors.forename: Dan
authors.initials: D
authors.lastname: Wu
authors.forename: Huimin
authors.initials: H
authors.lastname: Xie
authors.forename: Minjin
authors.initials: M
authors.lastname: Tang
authors.forename: Zhenxing
authors.initials: Z
authors.lastname: Hu
mesh_terms: D000818:Animals; D002080:Butterflies / Q000648:ultrastructure; D004867:Equipment Design / Q000295:instrumentation* / Q000379:methods*; D008853:Microscopy / Q000295:instrumentation* / Q000379:methods*; D014921:Wings, Animal / Q000648:ultrastructure
keywords: Linewidth; Micro-/nano-periodic structures; Moiré; SEM