Quantification of inhomogeneous residual strain in fractured amorphous silica via nano-beam electron diffraction

Strain engineering in layered materials comprising both crystalline and amorphous components is pivotal for modern electronic applications, ranging from flexible displays to high-mobility semiconductor devices. Precise strain measurement in these layered materials is crucial for optimizing device performance and reliability; however, while strain in crystalline layers has been extensively characterized, the mechanical behavior of amorphous layers remains largely unexplored due to their inherent atomic disorder. Here, we demonstrate that nano-beam electron diffraction (NBED) provides a robust pathway for analyzing local strain in amorphous materials by quantifying the ellipticity of diffraction rings. To elucidate the residual strain behavior under fracture conditions, we fabricated a strained amorphous silica lamella via a controlled ex situ stretching process. Using NBED combined with a custom geometric distortion correction algorithm, we achieved a high measurement precision of ±0.05%, enabling the successful mapping of subtle variation of residual strain fields. Our results reveal an inhomogeneous strain distribution that gradually increases toward the fracture edge, reaching a maximum residual strain of 0.1%. This work establishes a practical methodology for characterizing amorphous strain fields for advanced strain engineering in next-generation semiconductor devices.