Modeling of Laser Absorption and Modification Layer Formation Within Silicon Due to Stealth Dicing

Ultrathin dies with defect-free sidewall and high die strength are the industry gold standard. This is achieved by a new process stealth dicing (SD), in which silicon wafer is subjected to high-intensity infrared (IR) laser; with focal point within the bulk silicon, to cleave the wafer internally and induce crack. While early adaptation has made this as mature semiconductor manufacturing technology, the advent of disruptive circuitry design with focus on higher packing necessities the development of simulation model of the said process. This article presents an initial finding where the physics of laser–material interaction are applied to simulate the SD process. The SD model presented in this article details nonlinear IR laser absorption; heat-affected zone (HAZ) to simulate the formation of SD modified (MOD) layer formation within silicon. An in-house experiment with different configurations of pulse energy and focal depth was conducted for the model validation. Simulation results have been validated with the in-house experimental data and an $R^{2}$ value of 0.858 and 0.854 for single-beam MOD height and MOD width, respectively, have been found.