The prospect of employing nanophotonic methods for controlling photon–electron interactions has ignited substantial interest within the particle accelerator community. Silicon-based integrated dielectric laser acceleration (DLA) has emerged as a viable option by leveraging localized photonic effects to emit, accelerate, and measure electron bunches using exclusively light. Here, using highly regular nanopatterning over large areas while preserving the crystalline structure of silicon is imperative to enhance the efficiency and yield of photon-electron effects. While several established fabrication techniques may be used to produce the required silicon nanostructures, alternative techniques are beneficial to enhance scalability, simplicity and cost-efficiency. In this study, we demonstrate the nano-synthesis of silicon structures over arbitrarily large areas utilizing exclusively deep ultraviolet (DUV) ultrafast laser excitation. This approach delivers highly concentrated electromagnetic energy to the material, thus producing nanostructures with features well beyond the diffraction limit. At the core of our demonstration is the production of silicon laser-induced surface structures with an exceptionally high aspect-ratio -reaching a height of more than 100 nm- for a nanostructure periodicity of 250 nm. This result is attained by exploiting a positive feedback effect on the locally enhanced laser electric field as the surface morphology dynamically emerges, in combination with the material properties at DUV wavelengths. We also observe strong nanopattern hybridization yielding intricate 2D structural features as the onset of amorphization takes place at high laser pulse fluence. This technique offers a simple, yet efficient and attractive approach to produce highly uniform and high aspect ratio silicon nanostructures in the 200–300 nm range.

中文翻译：

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具有深紫外飞秒脉冲的高度均匀的硅纳米图案化


采用纳米光子方法控制光子-电子相互作用的前景在粒子加速器界引起了极大的兴趣。硅基集成介电激光加速 （DLA） 已成为一种可行的选择，它利用局部光子效应仅使用光来发射、加速和测量电子束。在这里，在大面积上使用高度规则的纳米图案化，同时保留硅的晶体结构，对于提高光子-电子效应的效率和产量是必不可少的。虽然可以使用几种成熟的制造技术来生产所需的硅纳米结构，但替代技术有利于提高可扩展性、简单性和成本效益。在这项研究中，我们展示了仅使用深紫外 （DUV） 超快激光激发在任意大面积上纳米合成硅结构。这种方法为材料提供高度集中的电磁能，从而产生具有远超衍射极限特征的纳米结构。我们演示的核心是生产具有极高纵横比的硅激光诱导表面结构 - 达到超过 100 nm 的高度 - 纳米结构周期为 250 nm。这一结果是通过利用表面形态动态出现时对局部增强激光电场的正反馈效应，结合 DUV 波长下的材料特性来实现的。我们还观察到强纳米图案杂化产生复杂的 2D 结构特征，因为非晶化的开始发生在高激光脉冲通量下。 该技术提供了一种简单但高效且有吸引力的方法，可在 200-300 nm 范围内生产高度均匀和高纵横比的硅纳米结构。