Recent semiconductor manufacturing has rapidly advanced toward three-dimensional integration to overcome the limitations of planar scaling. Conventional die-to-die bonding faces intrinsic limitations in alignment accuracy and productivity due to chip-level handling and repeated process steps. As an alternative, wafer-to-wafer bonding followed by wafer-level chip separation has attracted increasing attention, requiring a dicing technology capable of precisely separating bonded thick wafers without inducing defects. Mechanical blade dicing is limited by contact-induced chipping, residual stress, and yield loss caused by a relatively wide kerf width. In contrast, laser stealth dicing is a non-contact technique that forms an internal micro-crack layer, enabling high-precision separation with minimal mechanical and thermal damage through localized energy delivery and precise heat input control. In bonded wafers, however, the presence of a bonding interface can alter laser propagation and influence micro-crack formation and dicing behavior. In this study, Si-Si bonded wafers with a 200 nm thick SiO₂ interface were fabricated via direct bonding, and 750 μm thick specimens were diced using a near-infrared nanosecond pulsed laser. Cross-sectional observation, surface roughness analysis, and Raman spectroscopy were performed to evaluate crystalline quality and residual stress near the interface. Partial reflection and transmission of the incident laser beam were observed at the bonding interface, enabling efficient wafer separation without full-thickness laser scribing. These results provide insight for the efficient design of stealth dicing processes for wafer-level bonded structures.