Thermal treatments

A thermal treatment is usually required in many fabrication processes for microelectronics, photonics, solar cells, etc to induce dopant activation, recrystallization or to remove the residual damage, among others. Thermal budgets are characterized by their temperature-time profile, defined by the heating and cooling rates, the peak temperature and the duration of the annealing. Current techniques are evolving from long anneals at relative low temperatures (furnace) to extremely short anneals at high temperatures (spike and flash) or even melting and sub-melting anneals (laser), capable of achieving a high dopant activation with minimal diffusion.

The simulation of advanced thermal treatments requires an accurate definition of the models and parameters involved in defect and dopant evolution, due to the highly far-from-equilibrium conditions reached. We have analyzed the efficiency of flash anneal on end of range (EOR) damage removal combining kinetic Monte Carlo simulations, following the real temperature-time profile of the anneal, and TEM analysis of experimental samples. Several peak temperatures and implant energies were considered to determine the map for defect annihilation conditions.

EOR damage depth at which a complete damage removal is achieved as a function of flash anneal peak temperature. The blue region represents those conditions in which damage is totally annihilated, whereas in the orange region there are still defects. The characteristics of the samples analyzed by TEM are also indicated.