摘要
与传统的投影曝光微细加工方法相比 ,激光直写具有高柔性、低成本和胜任三维微型结构加工的优点。采用非稳腔的聚焦准分子激光 ( Kr F,λ=2 4 8nm)对单晶硅材料进行直接刻蚀 ,从微结构刻蚀的形状尺寸及加工过程的热效应等方面研究了准分子激光直接刻蚀单晶硅的加工特性。重点考察了加工中的热效应 ,研究表明准分子激光与被加工材料的相互作用并非完全基于非热机理 ,加工过程亦有热作用参与 ,进一步提出了准分子激光刻蚀加工的“热影响区”概念用以评价和解释准分子激光的“冷加工”特性。同时观察分析了脉冲激光对硅基底造成的破坏现象 ,讨论了冲击作用的成因。
Microfabrication technique is crucial to the development of MEMS (micro electro mechanical systems). Compared with projection processes, laser direct writing has such advantages as high flexibility and potential capability of fabricating 3D micromechanical structures. We for the first time in China carried out experiments on direct etching of monocrystal silicon with focused KrF excimer laser ( λ =248 nm) beam as shown in Fig.1. We mainly studied the thermal effect in excimer laser etching and the influence of beam property on processing results. Our main conclusions are as follows: (1) Excimer laser etching is not just a non thermal processing, so we highlight the concept of “heat affected zone (HAZ)” here, which is helpful to appreciate and explain “cold processing property” of excimer laser material processing. (2) The beam property and operation parameters are crucial to the etched shape and size. To improve micromachining performance, the unstable cavity, proper focusing mode and beam homogenizer should be considered. (3) The impact breakage formed in silicon wafers was also observed and the relevant causes were analyzed.
出处
《西北工业大学学报》
EI
CAS
CSCD
北大核心
2000年第3期491-495,共5页
Journal of Northwestern Polytechnical University
基金
陕西省自然科学基金!(96 D0 4
关键词
准分子激光
直接刻蚀
单晶硅
热影响区
冲击破坏
excimer laser, direct etching, “cold processing”property, heat affected zone (HAZ), impact breakage
