Depth profiles of Li ions implanted in the photoresist AZ111

Abstract

Depth profiles of 30–150 keV⁶Li implanted into the photoresist AZ111 have been analyzed through the ⁶Li(n,a)t nuclear reaction using thermal neutrons. As was found recently for ¹⁰B and ¹⁹F implanted into the same material, at certain threshold implantation energy the Li ions also split up into a regular and a nonregular distribution. This energy differs from the energies found for ¹⁰B and ¹⁹F, but at the threshold the electronic stopping power has the same value of about 20 eV/Å in the three cases. The nonregular Li fraction, typically around 10% of the implanted atoms, redistributes according to the TRIM code predicted profile of electronic energy transfer. The regular component exhibits a range profile that is well described by the TRIM code particle distribution predictions. The analysis of the B, F, and Li data shows that there is an approximately linear relation between the nonregular fraction of ions and the density of total deposited energy.