Popis: |
A systematic investigation has been carried out to study the influence of various annealings and implantations on the photoluminescence (PL) properties of phosphorus (P)-implanted Ge epitaxial films on Si substrate. For un-capped Ge samples, rapid thermal annealing (RTA) at 700 °C for 300 seconds yields the strongest PL emission peaked at 1550 nm. The influence of employing various capping layers (i.e., SiO(2), Si(3)N(4), and α-Si ) on the PL properties has been investigated. The capping layers are found to effectively decrease the dopant loss, leading to a significant PL enhancement. Si(3)N(4) is found to be the most efficient capping layer to prevent dopant out-diffusion and thus lead to strongest PL. Furthermore, it has been found that capping layers not only enhance the PL intensities but also make PL emission peak red- and blue- shift, depending on the stress type of the capping films. The effect of implantation dose on the PL has been also investigated. |