同步辐射光激励的二氧化硅薄膜刻蚀研究

利用热氧化法在硅晶片上生长SiO₂薄膜，结合光刻和磁控溅射技术在SiO₂薄膜表面制备接触型钴掩模，通过掩模方法在硅表面开展了同步辐射光激励的表面刻蚀研究，在室温下制备了SiO₂薄膜的刻蚀图样.实验结果表明：在同步辐射光照射下，通入SF₆气体可以有效地对SiO₂薄膜进行各向异性刻蚀，并在一定的气压范围内，刻蚀率随SF₆气体浓度的增加而增加，随样品温度的下降而升高；如果在同步辐射光照射下，用SF₆和O₂的混合气体作为反应气体，刻蚀过程将停止在SiO₂/Si界面，即不对硅刻蚀，实现了同步辐射对硅和二氧化硅两种材料的选择性刻蚀；另外，钴表现出强的抗刻蚀能力，是一种理想的同步辐射光掩模材料. 关键词： 同步辐射刻蚀 接触型钴掩模 二氧化硅薄膜

Synchrotron radiation stimulated etching of SiO2 thin films

The synchrotron radiation (SR) stimulated etching of SiO₂ thin film surface was investigated with a contact cobalt mask, and the etched pattern of SiO₂ thin films on silicon was made. The SiO₂ thin film was grown on silicon surface by thermal oxidation. The contact cobalt mask was fabricated on SiO₂ thin film by combining the techniques of photolithography and RF-magnetron sputtering. In the experiment, the anisotropic etching of SiO₂ was effectively achieved by SR radiation with SF₆ as the reaction gas. The etching rate increased with increasing gas pressure of SF₆ in a certain range, and with decreasing the substrate temperature. Under SR irradiation with flowing SF₆ and O₂ did not etch the silicon crystal and the etching stopped completely at the SiO₂/Si interface. Furthermore, the Co provided high resistance against the SR etching, indicating that Co is an ideal mask material for the synchrotron radiation stimulated etching.