Surface preparation and patterning by nano imprint lithography for the selective area growth of GaAs nanowires on Si(111)
Surface preparation and patterning by nano imprint lithography for the selective area growth of GaAs nanowires on Si(111)
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DOI：
10.1088/1361-6641/aa8c15
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发表时间：
2017-11-01
影响因子：
1.9
通讯作者：
Geelhaar, Lutz
中科院分区：
文献类型：
--
作者：
Kuepers, Hanno;Tahraoui, Abbes;Geelhaar, Lutz
在Si（111）衬底上选择性区域生长高垂直产率的Ga辅助GaAs纳米线仍然是一个挑战。在这里，我们探讨不同的表面制备和它们的影响NW生长的分子束外延。我们发现，在超纯水中煮沸的基板导致的垂直的纳米线（实现80%）的电子束光刻（EBL）图案化的基板上生长的产量显着提高。然而，我们把这种改进归因于掩模开口中衬底的原子粗糙度的降低。在此基础上，我们将我们的生长结果转移到衬底处理的技术，使大阵列，纳米压印光刻（NIL）的有效图案化。为了获得小于50的孔尺寸。我们联合收割机将传统的NIL工艺与间接图案转移（NIL-IPT）技术相结合。因此，我们实现了更小的孔尺寸比以前报道的传统的NIL和生长结果，这些EBL图案化基板上实现的。
The selective area growth of Ga-assisted GaAs nanowires (NWs) with a high vertical yield on Si(111) substrates is still challenging. Here, we explore different surface preparations and their impact on NW growth by molecular beam epitaxy. We show that boiling the substrate in ultrapure water leads to a significant improvement in the vertical yield of NWs (realizing 80%) grown on substrates patterned by electron-beam lithography (EBL). Tentatively, we attribute this improvement to a reduction in atomic roughness of the substrate in the mask opening. On this basis, we transfer our growth results to substrates processed by a technique that enables the efficient patterning of large arrays, nano imprint lithography (NIL). In order to obtain hole sizes below 50. nm, we combine the conventional NIL process with an indirect pattern transfer (NIL-IPT) technique. Thereby, we achieve smaller hole sizes than previously reported for conventional NIL and growth results that are comparable to those achieved on EBL patterned substrates.