Heat Transfer in Fast Linear Annealing for Direct Bonding of SOI Wafer Pairs

A novel silicon-on-insulator (SOI) manufacturing method, the fast linear annealing (FLA) method, is proposed. In the fast linear annealing method, a halogen lamp moves with a constant speed above a silicon wafer pair prebonded by the hydrogen iInteraction. In order to optimize the processing parameters such as the initial heat treatment time and the moving speed of the halogen lamp, bonding strengths were measured when the moving speed varies in the range of 0.05–0.5mm· s−1. The temperature distribution of SOI is analyzed numerically by using a finite difference method. The SOI is modeled two-dimensionally, and the alternate direction implicit (ADI) technique is used for the calculation of the temperature. The calculation results show that the SOI reaches a steady-state temperature distribution in an elapsed time of 380 s of halogen lamp irradiation. The maximum temperature of SOI does not vary significantly as the moving speed of the halogen lamp increases. These results agree with the measurement results, which show that the bonding strength from the high-speed anneal (0.5mm· s−1) was of similar strength to that from the slow speed (0.05mm· s−1) process.