Study of Ultra-shallow Junctions Formed by Flash Lamp Annealing to Reveal Dopant Activation Phenomenon

We studied the characteristics of ultra-shallow junctions (USJ) formed by flash lamp annealing (FLA) to reveal the nature of the dopant activation. A pre-amorphized layer is effective in activating dopants in FLA. End-of-range (EOR) defects remain close to amorphous/crystal (a/c) interface. FLA with low lamp power results in the amorphous layer remaining in the surface. Sb is highly activated, compared to As. These phenomena exhibit a correspondence with the activation during solid-phase epitaxial regrowth (SPER), where dopants are activated in a thermal non-equilibrium condition. Therefore, we conclude that FLA is a form of SPER, employing high temperatures and short (mili-second) times. The high temperature in FLA achieves higher dopant activation than obtained in SPER, whilst eliminating shortcomings found with SPER.