Kinetic aspects of the growth of platelets and voids in H implanted Si

We have undertaken a systematic and quantitative study of the extended defe cts formed after high-dose proton implantation in silicon. This study is ba sed on the transmission electron microscopy (TEM) and secondary ion mass sp ectroscopy (SIMS) experiments to "follow" the thermal evolution of platelet s and voids for a large variety of annealing conditions up to 900 degreesC. Up to about 500 degreesC, only platelets are observed and, as the anneal p roceeds, they grow in size and reduce their density through the conservativ e exchange of hydrogen (H) atoms. On the contrary, above 500 degreesC, H st arts to diffuse out of the defect-rich region and this out-diffusion can be completed after 700 degreesC anneals. Concurrently, platelets tend to disa ppear and voids appear. Above 700 degreesC anneals, hydrogen cannot be dete cted anymore in the layers and only voids remain, Upon time, they also grow in size and reduce their density. This is again attributed to the Ostwald ripening of voids which involves now vacancy diffusion from small voids to large ones. In summary, we have shown that platelets and voids both undergo quasi-conservative ripening upon annealing; at low-temperature (LT) platel ets exchange the H atoms they are composed of while at high-temperature voi ds exchange vacancies. (C) 2001 Elsevier Science B.V. All rights reserved.