Diffusion study of Kr, Rb and Xe implanted into positive and negative photoresist films

Abstract

In the present work results are reported of thermal diffusion of Kr and Rb implanted into AZ1350 positive photoresist films and Xe implanted into “waycoat” negative photoresist films. Kr and Xe ions were implanted at 80 K and the depth profiles determined in situ by using the Rutherford backscattering technique in a 80–473 K and 80–273 K temperature range respectively. The extracted Kr diffusion coefficients follow a linear Arrhenius plot over the studied temperature range with a characteristic activation energy of E b = 100 meV. The Xe diffusion into the “waycoat” photoresist develops in a very narrow temperature range (210–230 K) which only allows determination of the diffusion coefficient at 230 K. The Rb diffusional behavior was studied in a 273–473 K temperature range and it is characterized by an activation energy of E b = 300 meV. Comparison between the present and previous published results show that when implanted into the same polymer Kr and Xe display very similar diffusional characteristics. On the other side, the diffusion into the “waycoat” photoresist seems to be much faster than in the AZ1350 film. Finally a comparison between Rb and Kr results indicates that the Rb-photoresist bonds play an important role in the thermal diffusion process.