纳米尺度射流输运聚焦机理及电射流打印控制技术研究

It is an important way to print demand-based nano-structures by electrohydrodynamic flow (E-flow) for high resolution, high precision, and low cost nano-devices fabrication. As present, the maximum resolution of the electrohydrodynamic jet (E-jet) printing which is based on Taylor cone focusing theory only reaches submicron scale. To increase the printing resolution to sub-100 nm, a novel nano-printing method based on the theory of nanoscale E-flow transporting and focusing is proposed. The collision, scattering, multi-energy transporting processes of Argon ions at low pressure will be studied. The etching model of the Argon ions at dynamic-symmetrical electromagnetic-field will be constructed. The nozzle with sub-100 nm inner diameter will be fabricated. The formation mechanism of nanoscale Taylor cone at multi-physical fields will be studied. The theory of nanoscale E-flow transporting and focusing will be illuminated. The effect of the E-flow controlling parameters on the printing resolution will be clearly explained. The feedback control system based on nano-ampere current detection method will be constructed, and high resolution, high precision, low cost nano-structures with feature size of sub-100 nm can be printed on demand. Results from this project can be expect to provide a new view on the formation mechanism and controlling law of the nanoscale E-flow, and develop technology architecture for nano-resolution E-jet printing with flexible, simple, low-cost, practical features, which can significantly promote the application and development of the nano-devices.

利用电射流按需打印纳米结构是实现高分辨率、高精度、低成本纳米器件制造的重要途径。目前，基于泰勒锥流体聚焦原理的电射流打印最高分辨率仅达到亚微米量级。为将打印分辨率提高至100 nm以下，本项目提出基于纳米尺度电射流输运聚焦机理的纳米打印新方法。研究低气压下氩离子体碰撞散射和多能量传递过程，建立动态非对称电磁场中氩等离子体刻蚀模型，制造内径小于100 nm的纳米尺度喷针。分析多重物理场协同作用下纳米尺度泰勒锥的形成机制，阐明纳米尺度电射流输运和聚焦机理，明确射流控制参数对打印分辨率的作用途径和影响规律，构建基于纳安级电流检测反馈控制系统，实现特征尺寸小于100 nm的纳米结构高分辨率、高精度、低成本按需打印。研究成果将在科学层面上扩展人们对纳米尺度电射流形成机理和控制规律的认知，在工程应用上研发出一种灵活简单低成本实用型的纳米结构直写技术，推动纳米器件制造及应用的发展。

纳米尺度电射流的形成机理尚不明确，且电射流控制和纳米尺度喷针制造具有挑战。因此，项目深入研究了墨水在纳米通道内的滑移流动行为，根据滑移层和切向动量适应系数基本假设，推导了一阶和二阶速度滑移的墨水输运控制方程；以Navier-stokes方程和Scaling-law为基础，构建了纳米尺度电射流聚焦模型，并结合数值仿真，分析了直流和交流电场下，纳米尺度电射流的电荷和电场分布、喷射模式及射流激发条件；分析了等离子体刻蚀过程中的非均匀电场和浓度分布问题，优化了刻蚀工艺参数。开发了基于激光刻蚀、光学曝光和间隙控制的电射流喷针制造方法，最终制造了100 nm以下的纳米尺度聚合物电射流喷针；开发了电射流反馈控制系统，研究了打印控制参数和墨水物性对打印分辨率的影响规律，构建了电射流打印线宽计算模型和临近激发电压计算公式，实现了导电银浆、环氧树脂、光刻胶和聚合物等微纳尺度结构打印，最小线宽可达100 nm。此外，项目亦开发了氩等离子体辅助的AZ703光刻胶直写技术，打印线宽最小可以达到30 nm。项目研究成果将对微纳米器件制造、纳米尺度结构直写及其控制理论的发展具有重要参考价值和工程价值。