SiN薄膜纳米孔芯片制造工艺实验研究

Experimental research on fabrication of silicon nitride film nanopore device

针对第3代基因测序的需求,提出一种大规模的氮化硅薄膜纳米孔芯片制造技术.通过测量不同膜厚氮化硅薄膜的应力,选择适用于纳米孔制造的最佳厚度为100 nm.采用低压化学气相沉积、反应离子刻蚀和释放工艺制备出高成品率的氮化硅纳米薄膜芯片.在此基础上,使用聚焦离子束和高能电子束实现氮化硅薄膜纳米孔的制造.研究聚焦离子束刻蚀时间、电流与纳米孔直径的关系.实验结果表明,采用聚焦离子束将氮化硅薄膜的厚度减薄至40 nm以下时,制作纳米孔的效果更好.采用聚焦离子束制造的氮化硅薄膜纳米孔最小直径为26 nm,而采用电子束制备的最小直径可达3.5 nm.该方法为基于固体纳米孔的DNA测序检测提供了有力的支撑.

Aiming at the requirements of the third generation gene sequence technique,a fabrication method for large scale silicon nitride（ Si N） film nanopore device is presented. First,100 nm is chosen as the optimal thickness suitable for fabrication of nanopore through measuring the stress of Si N nanofilms with different thickness. High yield Si N nanofilm chips are manufactured by using lowpressure chemical vapor deposition（ LP-CVD）,reactive ion etching（ RIE） and release process.Then,focused ion beam（ FIB） and high energy electron beam are used to manufacture Si N film nanopore on Si N nanofilm chips after process optimization. Relationships between FIB etching time,beam current and the diameter of nanopore are researched. The experimental results showthat when the thickness of Si N is reduced to below40 nm by FIB milling,the fabrication effect of nanopore is better. The minimum diameters of Si N film nanopore for FIB and electron beam are 26 and 3. 5 nm,respectively. The proposed method provides strong support for DNA sequencing based on solid-state nanopore.