Flash Lamp Annealing For Wafer Debonding

Abstract

Debonding temporarily-bonded wafers at imec, is carried out using a 308nm Xenon Chloride excimer laser. This is indeed a well-established process in the 2.5D/3D packaging industry, since it comes with multiple advantages, particularly when compared to mechanical debonding. In this work, the authors investigate the implementation of Flash Lamp Annealing (FLA) as an alternative to laser ablation. Similarly to the latter, FLA debonding requires a release layer (RL) made of a light-absorbing material. The results of both heat diffusion modeling and debonding experimentation, show the importance of two key aspects for a successful debonding process: a highly visible light-absorbing material for a maximum effective fluence, and an insulating stack sandwiching the release layer.