【摘要】 利用聚焦离子束技术加工微结构时,由于溅射过程的再沉积效应,难以获得较为陡直的侧壁,对于高深宽比微结构尤甚。为优化聚焦离子束的加工工艺,提出一种单像素线辅助溅射刻蚀方法,对非陡直侧壁进行局部刻蚀修正,以期改善再沉积现象,提高侧壁陡直度。采用元胞自动机算法,对该方法应用于溅射过程时各参数对刻蚀结果的影响进行了数值模拟,获得了V型截面侧壁的修正效果,指出实际加工中局部刻蚀修正的位置选择存在着侧壁再沉积改善和离子束斑扩展之间的矛盾。聚焦离子束刻蚀实验验证了该方法的有效性,确定了局部刻蚀修正的最佳位置,在刻蚀宽度100 nm的圆环微结构时,沟道侧壁的校正效果较好,获得了深宽比为3∶1的沟槽结构。该方法可为相似微结构再沉积现象削弱提供技术支持。更多还原

【Abstract】 Redeposition is a common phenomenon in focused ion beam(FIB)sputtering,rendering the absence of a steep sidewall and actual processing size to be considerably different from the proposed design,particularly for high-aspect-ratio microstructures. To improve FIB microsputtering,a single-pixel line-assisted sputtering(SLAS)protocol based on local correction by additional sputtering is proposed to eliminate the redeposition effect and to significantly improve the perpendicularity of V-type sidewalls for a trench microstructure. A theoretical method based on a continuous cellular automaton(CCA)was utilized to simulate the redeposition effect and the perpendicularity improvement of V-type sidewalls upon the application of SLAS. Moreover,the CCA-based simulation suggested a contradiction between sidewall improvement and broadening of the ion beam spot. Further experiments demonstrated the validity of SLAS and confirmed the precise position of the SLAS area for achieving the best elimination of redepositing residue. Microtrenches of 100 nm in width were fabricated with satisfying steep sidewalls and a 3∶1 aspectratio. Generalizing this in situ elimination of redeposition in the field of FIB sputtering would be effective.更多还原