Thermal effect of ion implantation with ultra-short ion beams

Ion implantation with plasma guns operated in the detonation mode presents several differences from normally used low current ion implanter systems.

The most important differences are the high power of the beams generated with the plasma guns owing to their pulsed nature on one hand, and the plasma environment in which the target is immersed during the process of implantation on the other hand. Both effects were studied in this work.

The temperature profiles and their evolutions during and after nitrogen implantation in pure titanium, stainless steel and copper were investigated by using the finite differences method. The calculation for nitrogen ion implantation (fluence of 10¹³ cm^?2 and pulse time of 400 ns) in pure titanium, shows melting layers of 20 ns after the first 200 ns of implantation, with a fast cooling after the end of implantation. Thermal gradients of 1000 K μm^?1 and a heating rate of 5 K ns^?1 were also observed.

Optical spectroscopy observations (real time spectroscopy) of the implantation region show a highly activated nitrogen plasma.

Both effects can be of extreme importance in several applications such as, for example, titanium nitriding because of an extra temperature assisted absorption by the getter effect.