Fabrication of field emission and microdischarge devices using femtosemnd laser lithop-aphy

在本研究中，我们利用飞秒雷射微影技术制作场发射与微放电元件。实验结果如下：1.飞秒激光光刻提出了飞秒激光诱导非线性光刻和刻蚀的联合工艺。该工艺可以在非平面衬底上制作微结构，这是传统光刻工艺难以实现的.碳纳米管在微电极尖端上的空间选择性生长利用从覆盖有碳纳米管的微电极尖端引出的场发射电子束在Au薄膜上形成图形。研究了曲率半径、电极间隙长度和外加电压对场发射电子束加工Au薄膜的影响。曲率半径和外加电压的增加对场发射图形的形成都是有效的，产生了直径为2μm的图形。碳纳米管的空间选择性生长仅在微电极尖端的顶部。利用碳纳米管的微电极可以形成直径约2μm的图形.阵列式微放电腔采用半导体工艺在硅片上制作了空心阴极微电极腔阵列。单个空腔直径为30μm。在大气压Ar气中产生了稳定的辉光放电。采用O_2和Ar混合气体的无掩模微放电工艺，成功地在抗蚀剂薄膜上形成了直径为33 μm的图形。

In this study, we fabricated field emission and micro-discharge devices using femtosecond laser lithography. The experimental results are as follows:1. Femtosecond laser lithographyWe proposed the combined process of femtosemnd laser-induced nonlinear lithography and etching processes. This process enables to fabricate microstructures onto nonpanar substrates, which is rather difficult for the conventional photolithography processes.2. Space-selective growth of carbon nanotubes on a microelectrode tipThe patterns were formed on Au thin films by field emitted electron beams extracted from the microelectrode tips overall coated with carbon nanotubes. We investigated the effect of curvature radius, gap length between electrodes and applied voltages on the microfabrication of Au thin films by field emitted electron beams. The increases of curvature radius and applied voltages were effective for pattern formation by field emission, resulting in the patterns of 2μm diameters were created. Carbon nanotubes were space-selectively grown only on the top part of a microelectrode tip. The patterns of approximately 2μm diameters could be formed by using the microelectrodes with CNTs.3. Arrayed microdischarge cavitiesArrays of hollow cathode microelectrode cavities were fabricated in Si wafers by semiconductor technology. The diameter of individual cavity was 30μm. Stable glow discharges were generated in atmospheric pressure of Ar gas. The patterns of 33 μm diameters were successfully formed on a resist thin film by using maskless microdischarge processes with O_2 and Ar mixed gas.