Cryogenic large volume 3D characterization and damage free TEM sample preparation of beam sensitive materials using advanced multiple ion source PFIB integrated with dedicated flexible cryo stage

Session

FIB Applications & EM Samples Prep Techniques in Physical Sciences

Authors

Dr Min Wu (1), Dr Letian Li (1), Dr Haifeng Gao (1)

Affiliations

1. Thermo Fisher Scientific

Keywords

Cryogenic, beam sensitive materials, large volume, multi ion source PFIB, damage free 3D imaging, TEM sample preparation under cryogenic conditions

Abstract text

Direct quantitative investigation of the inner morphology and structure of materials is of critical importance to provide profound insights for properties evaluation. The scanning electron microscope (SEM) and focused ion beam (FIB), combined known as FIB-SEM or DualBeam, are conventionally recognized as a highly effective method to acquire 3D volume information. FIB-SEM together with integrated Automated Slice and View software has made the automated 3D data acquisition and analysis possible. However, slicing using Ga ion beam at room temperature has been found inducing severe damage to the beam sensitive materials, resulting in significant deterioration of the 3D data quality. Cutting edge cryogenic multi-ion source plasma FIB (PFIB) technique provides a fully automated workflow which allows large volume, damage-free ion beam slicing and high spatial resolution SEM acquisition during serial sectioning using various types of plasma ion beams under cryogenic conditions. With automated 3D reconstruction of the micrograph stacks, we can subsequently recover the comprehensive volume information of such beam sensitive materials. In addition, cryogenic multiple ion source PFIB has been confirmed to be capable of fabricating high quality large area TEM lamellae without damaging the beam sensitive bulk samples. Coupled with cryogenic in-situ nanomanipulator, the TEM samples can be easily lifted out under cryogenic conditions and subsequently transferred to TEM. 

In this paper we present a series of large volume 3D imaging results and TEM sample preparation examples of extremely beam sensitive samples. The samples were processed using xenon, oxygen or argon plasma ion source on Thermo Scientific Helios Hydra Plasma FIB platform under cryogenic conditions. The slicing and imaging acquisition was achieved using Automated Slice and View software and the subsequent data processing was conducted using Avizo 3D analysis and visualization software. The unique technical experiment set up and comprehensive application experience will be discussed in this presentation.