Challenges and opportunities for doping control in Ge for micro and optoelectronics applications

In this work we report two promising approaches to control dopant diffusion and promote dopant incorporation and electrical activation in Ge. The former is based on reducing the vacancy concentration, and hence the dopant diffusivity, by increasing the interstitial concentration through high-fluence O implant and the formation of stable GeO2 complexes. The other approach exploits the non equilibrium processes occurring under laser annealing, that lead to the incorporation (and electrical activation) of dopants to concentration levels much higher than those achievable by any other conventional technique; all the related phenomena occurring are hence studied in details.