Preparation Techniques for Cross‐Section Transmission Electron Microscopy Lamellas Suitable for Investigating In Situ Silicon–Aluminum Alloying at Grain Boundaries in Multicrystalline Silicon

Abstract

Herein, advanced preparation methods of cross‐section samples suitable for site‐specific studies of alloying processes are reported. To follow alloying processes in real time with the highest possible spatial resolution, in situ heating transmission electron microscopy (TEM) is conducted. As an industrially relevant model system, aluminum (Al) on multicrystalline silicon (mc‐Si) is chosen. Despite the tremendous advantages of in situ TEM compared with ex situ techniques, the development of suitable sample preparation recipes is a challenging task. As the standard focused ion beam (FIB) lift‐out fails for this preparation, three alternative methods are implemented. They show significant improvements compared with the widely used standard lift‐out and are described and evaluated in terms of contamination and overall lamella quality. Moreover, further improvements are discussed, leading to the conclusion that the new methods allow the reproducible preparation of lamellas suitable for site‐specific, in situ TEM alloying experiments.

Focused Ion Beam Sample Preparation for High Temperature In-situ Transmission Electron Microscopy Experiments: Use Carbon for Now

“…This work presents an approach to FIB preparation for samples that were heated in an electron microscope, demonstrates its viability, and emphasizes important problems with the most common (Pt and W) adhesion materials. Adhesion of the lamella is usually achieved via local ion-beam modification and deposition of a vapor-injected precursor; the poor thermal stability of most commonly used FIB-deposited materials at high temperatures presents a significant challenge for high temperature TEM imaging which needs to be addressed [1][2][3]. We will present the findings of our studies of the temperature stability of three commonly used FIB-deposited materials: Pt, W and C. Our initial studies were performed on FIB-deposited lines and blocks on SiN membranes, imaged over a temperature range from room temperature to approximately 1000 C heated using a furnace-style heating holder.…”

Advanced preparation of plan-view specimens on a MEMS chip for in situ TEM heating experiments

“… 8 , 33 With its cutting, material deposition, and mechanical micromanipulation abilities, the FIB is the preferred instrument to prepare MEMS chips for in situ experiments with cross-sectional lamellae. 4 , 34 , 35 However, in a wide variety of cases, the sole cross-sectional observation is insufficient for the reliable investigation of compositional or structural homogeneity of samples. 4 , 36 Despite many advantages of the FIB previously highlighted, the plan-view FIB sample preparation is still not a common practice mainly due to demanding restrictions compared to the preparation of cross-sectional lamellae.…”

Superhydrophobic aluminum alloy surface with excellent universality, corrosion resistance, and antifouling performance prepared without prepolishing

“…Aluminum and its alloys play a vital role in engineering materials due to their properties such as good ductility, low density, and excellent electrical conductivity. [ 1,2 ] Thus, they have been extensively used in various areas in our daily life, particularly in construction engineering, aerospace, transportation, and civilian industries. Nevertheless, aluminum is a highly reactive metal and prone to corrosion and contamination in wet and salty environments, which hinders its wide applications.…”