Elena Bruno

Diffusion and Clustering of B in Si: Basics and Defect Engineering Elena Bruno

Since the invention of the transistor at Bell Laboratories in the United States in 1947, almost all areas of our life have been touched by microelectronics, where silicon plays a dominant role as a basic material. Indeed, a continuous trend towards smaller but more powerful devices has been evidenced. Nonetheless, this miniaturization has been limited by difficulties in semiconductor device fabrication, further hampered by physical limits. Among dopants, B is absolutely the most used impurity to create p-type doped regions in silicon. Unfortunately the interaction with defects generated during the common industrial steps for devices production makes B to strongly diffuse and precipitate, hindering its use for ultra-shallow junction creation. Hence, new studies are required to face the problem. We deeply investigated the interaction of high B doped regions with the excess of defects generated by ion implantation and thermal annealing, as far as B precipitation, i.e. electical deactivation, and diffusion are concerned. The found results are hence used to develop new methodologies in order to control these two phenomena, by appropriate defect engineering.