RESUMEN
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.
RESUMEN
The bonding energy is an important parameter to evaluate the quality of bonded wafers in the semiconductor industry. The most important currently used method to measure the bonding energy is the so-called crack opening method. Unfortunately, the infrared cameras used for the wafer inspection with this method have limiting resolutions, and the derived direct crack length reading error is relatively large. To solve the reading error and adaptability problems, in this study, we improve upon the conventional image processing method and propose a crack length identification method that uses function fitting. The effectiveness and feasibility of the method are verified through experiments.