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European Microscopy Congress 2020 Abstract Database

In-situ heating and microstructural characterization using state of the art SEM-TKD stage

In-situ heating and microstructural characterization using state of the art SEM-TKD stage

Session

PST.5 - Diffraction techniques and structural analysis

Authors

Yevheniy Pivak (1), Vijay Bhatia (2), Mathilde Lemang (1), Christian Deen-van Rossum (1), H. Hugo Pérez-Garza (1)

Affiliations

1. DENSsolutions
2. THE UNIVERSITY OF SYDNEY

Keywords

 EBSD, In-situ biasing, In-situ heating, SEM, TKD

Abstract text

Thermal treatments are important process steps in nano- and micro-fabrication of multilayer structures and devices. The exact annealing temperatures and the duration are two very important parameters which influence the final properties of the devices through various effects like the nature of the phases in presence, the phase stability, defects formation, etc. It is therefore important to perform a microstructural analysis of those devices as a function of temperature.  

A common method to study thermal stability and microstructural evolution is ex-situ annealing and electron backscatter diffraction (EBSD) technique [1]. Although this approach works well, it can be very time consuming as the process is done in a repetitive manner using different equipment. Besides, EBSD method has some limitation in terms of spatial resolution for crystallographic analysis and contain some data artefacts [2]. The aim of this work is to apply an alternative technique and to use a state of the art SEM-TKD stage (Fig. 1) to follow microstructural evolution during heating in SEM/FIB in situ. 

A steel sample is used in this work as a model system. The in-situ heating was done using the MEMS (Microelectromechanical Systems)-based heating Nano-Chip [3] position in the TKD-SEM stage. A FIB sample was prepared on top of the electron transparent window of the Nano-Chip (Fig. 2).  The in-situ heating experiment was performed in a step wise approach in the temperature range from RT to 800 °C. The as-prepared sample has a BCC phase (Fig. 3). Starting 700 °C, a nucleation and a growth of the FCC phase is clearly visible from the phase colour maps (Fig. 3). We will present the design and the workflow of the SEM-TKD stage and the detailed results of the microstructural characterization of the steel sample using imaging, colour phase and IPX mapping during in-situ heating. Furthermore, we will discuss the perspectives and possible applications of the in-situ SEM/TKD method. 

Fig. 1: 3D model of the in-situ SEM and TKD stage. The stage contains 8 needles that can be used to apply heating and/or biasing stimuli to the sample, positioned on the MEMS Nano-Chip.

Fig. 2: SEM image of the FIB sample positioned on top of the circular electron transparent window (shown in black). The grey rectangle shows the area from which the phase and inverse pole figure maps were collected.

Fig. 3: (From left to right) Phase colour maps of the selected region of interest of the sample (Fig. 2) at RT, 650 °C, 700 °C, 800 °C and after 5 minutes at 800 °C. Blue and Red denote BCC and FCC phases, respectively.

References

[1] H. Alimadadi et al., Nat. Materials and Design 151, 60 (2018).

[2] A. Bastos S. Fanta et al., Ultramicroscopy 206, 112812 (2019). 

[3] J. T. van Omme et al., Ultramicroscopy 192, 14 (2018)