Surface Modification of Silicon at the Nanometer Scale

纳米级硅表面改性

• 批准号: 505225793
• 负责人: Professor Dr. Martin Ezequiel Garcia
• 金额: --
• 依托单位: Laserinstitut
• 依托单位国家: 德国
• 项目类别: Research Grants
• 资助国家: 德国
• 项目状态: 未结题
• 来源: https://gepris.dfg.de/gepris/projekt/505225793?language=en
• 关键词: Surface; Modification; Silicon; Nanometer; Scale

In order to improve the efficiency and applicability of laser micro- and nano-strucutring of silicon, the interaction of silicon with single- and multi-pulsed radiation is comprehensively investigated by time-resolved metrology and theoretical simulations. We develop a hybrid atomistic-continuum multiscale model that combines several numerical techniques in a single mesoscopic computational approach. The model includes at least five physical phenomena: First, the MD part for describing the laser-induced transient states of matter at the atomic level. Second, the effect of laser-generated free carriers (the electron-hole pairs) accounted in continuum. Third, non-thermal phase transitions due to newly developed interatomic potential. Fourth, the effect of SPP excitation on the laser-energy deposition. And finally, the CGMD method for modeling of large volumes of matter under low excitation and smooth laser-induced phase transitions under local equilibrium conditions. Moreover, the obtained laser-induced structures constituting the final periodic patterns can be separately studied in ab-initio calculations subjects to their new optical properties. The theoretical simulations are supported by spectroscopic imaging pump-probe ellipsometry measurements, which enable the comprehensive determination of the complex refractive index upon irradiation. Therefore, the investigation of the Si surface restructuring processes and its transient optical properties can be seen as a successful implementation and interconnection of the following theoretical and experimental objectives: Theoretical objectives:1) Development of the theoretical description of the ultrashort laser-pulse interaction with semiconductors on the example with Si.2) Verification of the model predictions with the experimental measurements.3) Investigation of the role of non-thermal processes involved into the laser-induced phase transitions in Si.4) Development of the methodology of designing the experiment for functionalization of Si surface with demanded optical properties in IT-technologies.Experimental objectives:1) extend spectral range of pump probe setup into the UV.2) comprehensive investigation of transient complex refractive index n ̃(t,H,λ).3) develop optical gradient index model by complementary consideration of experiment and simulation.4) determine transient complex refractive index n ̃(t,H,λ) for multipulse irradiation for LIPSS formation.The project studies the transient state of Si as a representative of a large group of semiconductors. A number of results obtained in this project, therefore, can be extended to In, As, Ge, and other materials, highly demanded in microelectronics and nanotechnologies. The deep understanding of the laser-induced processes can result in ability of manipulation with the transient optical properties of Si and development of new generation of electronic devices at the nanoscale.

为了提高激光对硅微纳结构化的效率和适用性，本文采用时间分辨计量和理论模拟的方法，对单脉冲和多脉冲激光与硅的相互作用进行了全面的研究。我们开发了一个混合原子连续多尺度模型，结合了几种数值技术在一个单一的介观计算方法。该模型至少包括五个物理现象：第一，分子动力学部分，用于描述原子水平上的激光诱导物质的瞬态。第二，激光产生的自由载流子（电子-空穴对）的影响在连续的帐户。第三，非热相变由于新开发的原子间势。第四，SPP激发对激光能量沉积的影响。最后，CGMD方法用于模拟低激发下的大体积物质和局部平衡条件下的平滑激光诱导相变。此外，所获得的激光诱导的结构构成的最终周期性图案可以单独研究在从头计算科目的新的光学性质。理论模拟支持光谱成像泵浦-探测椭圆偏振测量，这使得照射后的复折射率的全面测定。因此，对Si表面重构过程及其瞬态光学性质的研究可以被视为以下理论和实验目标的成功实现和互连：理论目标：1）以Si为例，发展超短激光脉冲与半导体相互作用的理论描述。2）用实验测量验证模型预测。3）研究非热过程在Si激光诱导相变中的作用。4）开发IT技术中具有所需光学特性的Si表面功能化实验设计方法。实验目标：1）将泵浦探测装置的光谱范围扩展到紫外; 2）全面研究瞬态复折射率n <$（t，H，λ）; 3）通过实验和模拟的互补考虑，建立光学梯度折射率模型; 4）确定瞬态复折射率n <$（t，H，λ），λ）用于LIPSS形成的多脉冲辐照。该项目研究了作为一大组半导体代表的Si的瞬态。因此，在本项目中获得的一些结果可以扩展到微电子和纳米技术中高度需求的In，As，Ge和其他材料。对激光诱导过程的深入理解可以导致对Si的瞬态光学性质的操纵能力和新一代纳米电子器件的开发。