Department of Chemical Engineering, University of Arkansas, Bell 3202, Fayetteville, Arkansas 72701, USA.
Langmuir. 2010 Feb 2;26(3):1533-8. doi: 10.1021/la903985m.
Gold nanoparticle arrays created with electroless gold plating provide a unique means of transforming nanocylinders usually formed in electron beam lithography to spherical nanoparticles. Alone, electroless gold plating is not selective to the substrate and results in the formation of a gold film on all exposed surfaces of an electron beam patterned sample, including the electron resist. Undesired gold plating occurred near patterned features on the substrate surface, which was reduced by increasing post-spin-coat cure time. When the electron resist is removed, some nanocylinders break off with the gold film, leaving partial cylinders or holes in the patterned elements. By presensitizing the substrate surface with tin, gold cylinders may be selectively deposited to the substrate surface without forming a film on the electron resist. Tin presensitized arrays were produced with 47.1 +/- 7.4 nm radius gold nanoparticles with an interparticle distance of 646.0 +/- 12.4 nm. Defects from sheared, missing, and redeposited Au particles associated with the resist removal were minimized, resulting in enhanced size and shape uniformity of pillars and arrays. Hollow particles were eliminated, and relative standard deviation in particle size was reduced by 7.4% on average, while elongation was reduced 12.3% when astigmatism was eliminated.
采用无电电镀金的方法制备金纳米粒子阵列，为将通常在电子束光刻中形成的纳米圆柱转变为球形纳米粒子提供了一种独特的方法。单独使用无电电镀金对基底没有选择性，会导致在电子束图案化样品的所有暴露表面（包括电子抗蚀剂）上形成金膜。在基底表面的图案特征附近会发生不需要的电镀金，通过增加旋涂后固化时间可以减少这种情况。当去除电子抗蚀剂时，一些纳米圆柱会与金膜一起脱落，在图案化元素中留下部分圆柱或孔。通过用锡对基底表面进行预敏化，可以将金圆柱选择性地沉积到基底表面上，而不会在电子抗蚀剂上形成膜。采用锡预敏化的方法制备了具有 47.1 ± 7.4nm 半径和 646.0 ± 12.4nm 粒子间距离的金纳米粒子阵列。与去除抗蚀剂相关的剪切、缺失和再沉积 Au 颗粒的缺陷最小化，从而提高了圆柱和阵列的尺寸和形状均匀性。消除了空心颗粒，平均粒径的相对标准偏差降低了 7.4%，同时消除了像散后，长径比降低了 12.3%。
