飞秒激光掩模版加工中的精度控制方法

飞秒激光掩模版加工和修复是近几年来微纳加工领域的研究热点之一,其中精度控制是获得高质量掩模版的关键.在飞秒激光脉冲对铬金属膜和石英基底材料破坏特性的理论基础上,利用一套输出脉宽25fs、最大功率1 W、中心波长800 nm、重复频率1 kHz的飞秒脉冲激光系统,实验研究了掩模特征单元尺寸与激光能量密度、扫描速度的关系,通过参数优化实现了最小特征尺寸为290 nm的掩模版加工;探讨了特征单元的边缘形貌和底部形貌受能量密度与扫描次数的影响规律,提出了加工参数的选取原则,最终实现了飞秒激光掩模版加工的精度控制和优化.

Precision control methods in the fabrication of mask via femtosecond laser irradiation

Femtosecond laser mask fabrication and repair is a research focus in micro-and nano-manufacturing field,precision control is the key to obtain high quafity mask.Precision control methods for the femtosecond laser fabrication of mask were proposed.On the basis of the theoretical researches on the damage characteristics of femtosecond laser pulse on the chromium film and the fused silica,a femtosecond pulsed laser system with the output pulse width of 25 fs,the maximum power of 1 W,the central wavelength of 800 nm and the repetition rate of 1 kHz was adopted in experiments.The relationships among the feature size of micro-structure,laser energy density,and scan speed were studied,and a mask with the critical dimension of 290 nm was fabricated with the optimized processing parameters.Furthermore,the effects of energy density and scan times on the edge and bottom morphologies of micro-structures were discussed,and some important principles for selecting the processing parameters were proposed to realize precision control and optimization of mask quafity.