Lifetime and Stability of Silicon Nitride Nanopores and Nanopore Arrays for Ionic Measurements.
Lifetime and Stability of Silicon Nitride Nanopores and Nanopore Arrays for Ionic Measurements.
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DOI：
10.1021/acsnano.9b09964
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发表时间：
2020-06-23
期刊：
影响因子：
17.1
通讯作者：
Drndic, Marija
中科院分区：
文献类型：
--
作者：
Chou, Yung-Chien;Das, Paul Masih;Monos, Dimitri S.;Drndic, Marija
关键词：
纳米孔在包括DNA测序和分子过滤在内的许多应用中都很有前景。对于需要耐久性和在更大范围外部参数下操作的应用，固态纳米孔比其生物对应物更受青睐，但很少有研究关注于优化其稳健性。我们报道了10到100纳米厚的低应力氮化硅（SiNx）膜的孔隙和多孔阵列的寿命和耐久性。孔是用透射电子显微镜（TEM）和/或电子束光刻（EBL）和反应离子蚀刻（RIE）制备的，直径从2到80纳米。我们将它们储存在不同的电解质溶液中（KCl, LiCl, MgCl2），并记录几个月的开孔电导率，以量化孔稳定性。在0.01 ~ 3 M KCl条件下，孔径随时间的增加而增大，孔径腐蚀速率随电解液浓度的增加而增加，分别为Δd/Δt ~ 0.2 ~ 3 nm/d。TEM证实了离子测量的直径腐蚀速率范围。利用电子能量损失谱（EELS），我们观察到tem钻孔孔边缘周围有一个缺氮区。孔隙膨胀是由Si/SiO2孔壁的蚀刻引起的，这类似于二氧化硅（SiO2）等矿物质中硅在咸水中的溶解。蚀刻过程发生在薄膜暴露于电子束的地方，可以导致孔的形成。然而，在1 M KCl中，1 nm厚的合形氧化铪层涂层孔可以防止膨胀，这与裸SiNx孔（~ 1.7 nm/天）形成鲜明对比。EELS数据揭示了裸孔和hfo2包覆孔的原子组成。
Nanopores are promising for many applications including DNA sequencing and molecular filtration. Solid-state nanopores are preferable over their biological counterparts for applications requiring durability and operation under a wider range of external parameters, yet few studies have focused on optimizing their robustness. We report the lifetime and durability of pores and porous arrays in 10 to 100 nm-thick, low-stress silicon nitride (SiNx) membranes. Pores are fabricated using a transmission electron microscope (TEM) and/or electron beam lithography (EBL) and reactive ion etching (RIE), with diameters from 2 to 80 nm. We store them in various electrolyte solutions (KCl, LiCl, MgCl2) and record open pore conductance over months to quantify pore stability. Pore diameters increase with time, and diameter etch rate increases with electrolyte concentration from Δd/Δt ~ 0.2 to ~ 3 nm/day for 0.01 to 3 M KCl, respectively. TEM confirms the range of diameter etch rates from ionic measurements. Using electron energy loss spectroscopy (EELS), we observe a N-deficient region around the edges of TEM-drilled pores. Pore expansion is caused by etching of the Si/SiO2 pore walls, which resembles the dissolution of silicon found in minerals such as silica (SiO2) in salty ocean water. The etching process occurs where the membrane was exposed to the electron beam and can result in pore formation. However, coating pores with a conformai 1 nm-thick hafnium oxide layer prevents expansion in 1 M KCl, in stark contrast to bare SiNx pores (~ 1.7 nm/day). EELS data reveal the atomic composition of bare and HfO2-coated pores.
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影响因子：
4.2
作者：
Madejski G;Lucas K;Pascut FC;Webb KF;McGrath JL
通讯作者：
McGrath JL
影响因子：
2.9
作者：
Healy, Ken;Ray, Vishva;Willis, Lauren J.;Peterman, Neil;Bartel, John;Drndic, Marija
通讯作者：
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影响因子：
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通讯作者：
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影响因子：
41.2
作者：
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通讯作者：
Golovchenko, JA