基于刻蚀抑制剂成膜行为的等离子体刻蚀自组织效应微观机制研究

As a key technique in nano/micro-patterning, plasma etching often causes surface roughness, which generally takes the form of periodic nano/micro-structures with uniform size and shape. Plasma etching has suffered for decades from this roughening effect because it degrades the device performance. Nowadays, plasma-directed roughening effect is gradually utilized for surface nano-texturing, which has a great future in the fields of optics, biology and environmental science. Given the fact that the microscopic mechanism governing the formation and evolution of the plasma etching directed organization still remains unclear, this research proposal attempts to study the governing mechanism from the perspective of filming of depositing etching product. The interrelationship between the plasma-directed organization and the Volmer-Weber film growth model of depositing etching product caused by the poor wettability of etched substrate by the depositing etching products is identified. Firstly, the impacts plasma etching parameters having on depositing parameters and the governing mechanism are investigated. Secondly, the formation and evolution behavior of depositing film are theoretically predicted based on kinetic Monte Carlo and consequently further verified in experimental investigation during which the formation and evolution behaviors of surface textures are studies. The implementation of this proposal will benefit the avoiding or precise control of plasma directed organization both scientifically and technologically.

作为微纳加工核心技术之一，等离子体刻蚀常引起微观上表现为周期性微纳结构的刻蚀表面粗糙化。传统上，这会降低图形转移精度和元器件性能，因而成为困扰等离子体刻蚀多年的问题。近年来，该效应被逐步积极应用于表面微织构领域，在光学、生物和环境等领域逐步显现广阔的应用前景。本项目针对自组织效应微观机理不清晰问题，将微结构的形成与刻蚀沉积物的岛状成膜方式关联起来；从等离子体刻蚀环境下刻蚀抑制剂在刻蚀表面成膜动力学的角度研究微结构的形成和演化过程。重点研究等离子刻蚀工艺对刻蚀抑制剂成膜条件的影响机制；进而分析刻蚀抑制剂在自身性质、分子间作用势、刻蚀环境等内外作用下的成膜行为。然后开展等离子体刻蚀验证实验，对比刻蚀抑制剂成膜特性与微结构形成和演化特性的吻合程度。研究成果可为不同应用背景下刻表面微结构的抑制或调控提供科学依据和理论支持。

作为微纳加工核心技术之一，等离子体刻蚀常引起微观上表现为周期性微纳结构的刻蚀表面粗糙化。传统上，这会降低图形转移精度和元器件性能，因而成为困扰等离子体刻蚀多年的问题。近年来，该效应被逐步积极应用于表面微织构领域，在光学、生物和环境等领域逐步显现广阔的应用前景。本项目针对自组织效应微观机理不清晰问题，将微结构的形成与刻蚀沉积物的岛状成膜方式关联起来；从等离子体刻蚀环境下刻蚀抑制剂在刻蚀表面成膜动力学的角度研究微结构的形成和演化过程。系统研究了刻蚀诱导粗糙化的动力学过程，构建了基于动力学蒙特卡洛思想的微观刻蚀模型；该模型重点考虑刻蚀抑制剂在自身性质、分子间作用势、刻蚀环境等内外作用下的成膜行为机制。该模型所预测的自组织结构的拓扑特性（相对平缓的低频背景表面和高频微凸起相互叠加而成的“二元尺度”微观形貌）、演化过程（随着刻蚀时间增加，微凸起的横纵向尺寸不断增大，密度减小，平均间距增大）、微结构特性（有无、密度、尺寸、形状等）随刻蚀工艺参数(抑制剂及基底的材质、基底温度、离子轰击能量等)的变化规律与实验观测结果高度吻合；研究结果明确了刻蚀诱导自组织效应与抑制剂岛状生长的关联性，揭示了等离子体刻蚀诱导表面微结构的形成和演化的微观机制，构建了自组织结构形成演化过程的理论模型，可为不同应用背景下刻蚀表面微结构的抑制或调控提供科学依据和理论预测工具。