Atomic layer deposition of ZnO on thermal SiO2 and Si surfaces using N2-diluted diethylzinc and H2O2 precursors
Atomic layer deposition of ZnO on thermal SiO2 and Si surfaces using N2-diluted diethylzinc and H2O2 precursors
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DOI：
10.1016/j.apsusc.2012.01.054
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发表时间：
2012-03
影响因子：
6.7
通讯作者：
Ke-Jia Qian;Sun Chen;B. Zhu;Lin Chen;S. Ding;Hongliang Lu;Qingqing Sun;David-Wei Zhang;
中科院分区：
文献类型：
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作者：
Ke-Jia Qian;Sun Chen;B. Zhu;Lin Chen;S. Ding;Hongliang Lu;Qingqing Sun;David-Wei Zhang;
由于多个激子的产生，氧化锌纳米点在各种光电应用中引起了越来越多的关注。本文首次采用氮气稀释的DEZn和H_2O_2气体为前驱体，在SiO_2和Si表面实现了纳米点的原子层沉积(ALD)生长。实验结果表明，在沉积温度为200℃的情况下，AlD型氧化锌具有波纹表面的纳米晶薄膜，这可能是由于氧化锌纳米点之间的愈合所致。当沉积温度提高到300℃时，氧化锌以分散的纳米点的形式生长。这是由于在300℃时反应分子的脱附增加和生长表面成核位的减少，从而导致从热力学和能量的角度来看，DEZn和OH基团之间的反应只在一些有利的位置上进行。在二氧化硅表面热稳定性方面，经过100次循环，得到了密度约为5×1010 cm−_2的氧化锌纳米点。在硅表面，经过50次循环，得到了密度高达∼1×1011 cm−2的氧化锌纳米点。最后，X射线光电子能谱和X射线衍射分析表明，在300℃时，AlD型氧化锌主要由氧化锌键和少量的氢氧化锌键组成，300℃的沉积温度有利于氧化锌(002)择优取向的生长和晶体尺寸的增大。
ZnO nanodots are attracting more and more attention in various photoelectrical applications due to multiple excition generation. In this article, atomic layer deposition (ALD) growth of ZnO nanodots has been realized for the first time on both thermal SiO2and Si surfaces using N2-diluted gaseous DEZn and H2O2precursors. The experimental results indicate that the ALD ZnO exhibits a nano-crystalline film with corrugated surfaces in the case of the deposition temperature of 200°C, likely due to concrescence among ZnO nanodots. When the deposition temperature is increased up to 300°C, ZnO is grown in the form of well-discrete nanodots. This is due to increased desorption of the reacting molecules and a reduction of nucleation sites on the growing surfaces at 300°C, thus leading to the reaction between DEZn and OH groups only on some favorable sites from thermodynamic and energy points of view. In terms of the thermal SiO2surface, ZnO nanodots with a density of around 5×1010cm−2are obtained for 100 cycles. As for the Si surface, ZnO nanodots with a density as high as ∼1×1011cm−2are achieved for 50 cycles. Finally, the X-ray photoelectron spectroscopy and X-ray diffraction analyses reveal that the ALD ZnO at 300°C is dominated by ZnO bonds together with a small quantity of ZnOH bonds, and the deposition temperature of 300°C can result in preferential growth of ZnO (002) orientation and a bigger crystallite size.