4:45 PM - 5:15 PM
▲ [13p-A303-9] Application of Neon Ion Beam for Processing III-V Semiconductors and Atom Probe Sample Preparation of Ga sensitive materials
Keywords:Neon Ion Beam, Atom Probe Tomography, III-V Semiconductor
Focused ion beam (FIB) milling using Gallium ions is routinely used for the site-specific sample preparation of cross-sections, Transmission Electron Microscopy (TEM) lamella and Atom Probe Tomography (APT) tips. While the Ga FIB has been a versatile tool on a variety of materials, there are exceptions such as Al, In, Sn and III-V semiconductors where Ga irradiation and implantation causes detrimental effects including intermixing, implantation and accumulation of Gallium at the surface and grain boundaries, and Ga droplet formation. With the advent of novel FIB sources, alternative ion species for precision milling are now available. For example, Ne-FIB-milling as the final polishing step in the preparation of TEM lamella has been demonstrated as an alternative approach for samples in which gallium contamination cannot be tolerated. In this contribution, we present results from the application of Ne ions in the milling GaAs and final polishing of APT tips.
Conventional processing of GaAs and GaN with Ga FIB-SEMs at room temperatures is well known to produce Ga-rich droplets and pores. Here we employ the Ne ion beam for direct sputtering of GaAs to create trenches and structures as small as 20 nm. Optimization of the ion beam landing energy and current for preparing flat bottom trenches and side walls without Ga droplets will be presented.
The APT tips are extracted from bulk samples using Ga-FIB in situ lift out with final polishing using Ne ions. Materials investigated include a titanium alloy and a sample comprising aluminum/aluminum oxide layers on a silicon substrate. High-resolution TEM analysis of Ne-FIB-milled tips reveals that implanted gallium from the pre-milling steps is successfully removed. A thin amorphous layer of ~ 5nm is observed, beneath which the crystallinity of the tip is well-preserved. The experimental workflows for the Ne-FIB technique will be discussed and the 3D reconstructions from the APT measurements will be presented.
Conventional processing of GaAs and GaN with Ga FIB-SEMs at room temperatures is well known to produce Ga-rich droplets and pores. Here we employ the Ne ion beam for direct sputtering of GaAs to create trenches and structures as small as 20 nm. Optimization of the ion beam landing energy and current for preparing flat bottom trenches and side walls without Ga droplets will be presented.
The APT tips are extracted from bulk samples using Ga-FIB in situ lift out with final polishing using Ne ions. Materials investigated include a titanium alloy and a sample comprising aluminum/aluminum oxide layers on a silicon substrate. High-resolution TEM analysis of Ne-FIB-milled tips reveals that implanted gallium from the pre-milling steps is successfully removed. A thin amorphous layer of ~ 5nm is observed, beneath which the crystallinity of the tip is well-preserved. The experimental workflows for the Ne-FIB technique will be discussed and the 3D reconstructions from the APT measurements will be presented.