Study of annealing induced redistribution of implanted Au in Si: Fluence dependence

Fabrication of silicon nanocrystals using sequential Au ion implantation

“…The RBS spectra corresponding to annealed samples at different temperatures i.e 550, 650, and 750, 850 and 950 o C has been shown in Figure 6 (a) and (b) respectively. Our previous work on single keV implantation followed by annealing reveals inward diffusion of Au in Si [25]. Followed by that, in the present study, we expect the keV implanted Au diffuses towards the Au/Si interface whereas the MeV implanted Au outdiffuses to the surface resulting in a bi-modal distribution of Au in Si matrix.…”

“…A detailed RUMP analysis of the annealed samples reveals that Au-Si layer thickness decreases and Au layer rises as we increase the annealing temperature. Simulation for the annealed sample at 550 o C, shows that the pre annealed layered structure gets rearranged (due to annealing) and a 5 nm layer consisting of Au nano/micro-particles [25] is present between layer 1 and layer 2. A schematic diagram explaining the above has been shown in Fig.…”

Study of thermal recrystallisation in Si implanted by 0.4‐MeV heavy ions

“…It is shown that thermal annealing at temperatures greater than or equal to 500°C results in a solid‐phase epitaxial recrystallisation of the a ‐Si layer . Since the solid solubility of Au in a ‐Si is much higher than that in c ‐Si, solid‐phase epitaxial recrystallisation of the a ‐Si layer at temperatures approximately 500°C results in separation of Au atoms into the narrowing a ‐Si layer, causing the observed out‐diffusion of Au . A typical bimodal profile indicates that parts of dopants remind still in depth and this feature was observed for instance in Macková et al and is connected to the substantial modification of structure, where nanocrystallites and voids can appear after the implantation.…”

“…Point defects can agglomerate and form extended defect clusters of Si interstitials and clusters of vacancies and cavities, which require annealing temperatures of 800°C to 1000°C to be removed . Au implantation into Si was studied, eg, in Priolo et al, Mohapatra and Mahapatra, and Kamila et al, gold‐silicide formation in Green and Bauer, metal‐induced crystallisation, and Au out‐diffusion and in‐diffusion in Si, etc for advanced semiconductor device application. We decided to follow phenomena connected to Si crystal recovery and possible ions diffusion.…”