Focused ion beam applications using gas field and liquid metal alloy ion sources

Focused ion beams are often considered as tools required for the sample preparation for
other techniques such as transmission electron microscopy. However, in this presentation I
would like to convince you that by using other sources than ubiquitous Gallium liquid metal
ion source a wide range of interesting and challenging problems can be addressed in a very
flexible way. I will focus on applications enabled by the usage of gas field (GFIS) [1–3] and
liquid metal alloy ion sources (LMAIS) [4]. Among other examples I want to present some
recent results obtained using Ne and He GFIS based helium ion microscopy (HIM). I will
show how the HIM can be used to create arbitrary shaped ferromagnets using Fe60 Al40 [5]
as well as anti-ferromagnets in Co/Pt/Ru multilayers [6]. Using in-situ probing I will show
how to tune the spin torque interaction in a Pt/Co/W multilayer sample such that current
switchable magnetization patterns can be created[7]. Finally, I’d like to present recent results
related to the epitaxial overgrowth of tin spheres driven and observed by HIM [8].
In the second part of my talk I want to present results obtained using LMAIS based FIBs.
This includes our recent effort to create single photon emitters (SPE) in Si. We use LMAIS
based Si irradiation to create single W and G centers in two different Si base materials. The
obtained yield for the G-centers is more than 50% and the lateral precision is ≈100 nm. I
will also show how this process can be scaled up to avoid the flexible but serial FIB approach
and switch to broad beam irradiation [9]. Finally, I want to show that also LMAIS based
FIB can be used to control magnetic properties on the nanometer scale with high precision.
Examples include the implantation of up to 10% of Co into permalloy with a lateral resolution
of 30 nm and the control the Gilbert damping of the magnetization dynamics by four orders
of magnitude using a Dy LMAIS. An outlook on new sources currently under development
will conclude the talk.