High-Precision Wafer Bonding Alignment Mark Using Moiré Fringes and Digital Grating

Abstract

This paper investigates a moiré-based mark for high-precision wafer bonding alignment. During alignment, the mark is combined with digital grating, which has the benefits of high precision and small size. A digital grating is superimposed on the mark to generate moiré fringes. By performing a phase calculation on the moiré fringe images corresponding to the upper and lower wafers, the relative offset of the upper and lower wafers can be accurately calculated. These moiré fringes are exceptionally stable, thereby enhancing the alignment stability. In this study, through practical experiments, we tested the rationality and practicability of the mark.

A dynamic and nonlinear time grating subdivision method for magnetic levitation ruler

“…Based on the relationship between the subdivision error obtained by the grating sensor's output Moir é fringes electrical signal and the error parameters contained in the output Moir é fringes electrical signal, a signal compensation method is designed to convert the phase non orthogonal error of the two Moir é fringes electrical signals into amplitude coefficient unequal error [5]. From the perspective of amplitude subdivision method, many domestic and foreign scholars have started to study software subdivision algorithms, which linearize the collected Moir é fringes electrical signals through programming methods, namely electronic amplitude subdivision method [6]. Based on the linearized function, subdivision is carried out to achieve the subdivision goal of a gate spacing [7].…”

Study of window functions for the Moiré fringe phase demodulation

“…Moreover, the moiré fringe measurement method offers many advantages, including noncontact measurement, high accuracy, wide measurement range, strong applicability, fast and efficient operation, minimal sensitivity to environmental conditions, and visualizability. It finds wide-ranging applications in fields such as microelectronics, optical components, mechanical engineering, and biomedical sciences [5,6] . In recent years, with the advancement of precision instruments and digital signal processing, the measurement accuracy of moiré fringe methods has been continuously improving.…”