Silicon wafer wettability and aging behaviors: Impact on gold thin-film morphology
Silicon wafer wettability and aging behaviors: Impact on gold thin-film morphology
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DOI：
10.1016/j.mssp.2014.03.044
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发表时间：
2014-10-01
影响因子：
4.1
通讯作者：
Yue, W. S.
中科院分区：
文献类型：
--
作者：
Yang, X. M.;Zhong, Z. W.;Yue, W. S.
本文报道了用piranha（硫酸（H2SO4，96%）和过氧化氢（H2O2，30%）的3：1混合物，120 ℃）、SCI（NH4OH、H2O2和H2O的1：1：5混合物，80 ℃）或HF溶液（6份40%NH4F和1份49%HF，室温）溶液清洗并用气态等离子体处理的硅晶片的润湿性和老化行为。使用食人鱼或SC 1溶液清洗的硅片具有亲水性，表面的水接触角会沿着增加，直到达到70度左右的饱和点。这些晶片在真空中的接触角增加速率比在开放空气中快得多，这是由于物理吸附在晶片表面上的水的损失。用HF溶液清洗的硅晶片是疏水的。它们的接触角在大气中减小，而在真空中增加到95度。沉积在亲水性晶片上的金薄膜比沉积在疏水性晶片上的金薄膜更光滑，这是因为在成核阶段，在亲水性表面上形成的大量氧基团会与溅射过程中的金吸附原子反应以形成连续的薄膜。氩气、氮气、氧气等离子体处理可以通过产生薄（约2.5nm）的二氧化硅膜来将硅晶片表面从疏水性改变为亲水性，该二氧化硅膜可以用于改善金薄膜的粗糙度和粘附性。(C)2014爱思唯尔有限公司版权所有。
This paper reports on the wettability and aging behaviors of the silicon wafers that had been cleaned using a piranha (3:1 mixture of sulfuric acid (H2SO4, 96%) and hydrogen peroxide (H2O2, 30%), 120 degrees C), SCI (1:1:5 mixture of NH4OH, H2O2 and H2O, at 80 degrees C) or HF solution (6 parts of 40% NH4F and 1 part of 49% HF, at room temperature) solution, and treated with gaseous plasma. The silicon wafers cleaned using the piranha or SC1 solution were hydrophilic, and the water contact angles on the surfaces would increase along with aging time, until they reached the saturated points of around 70 degrees. The contact angle increase rate of these wafers in a vacuum was much faster than that in the open air, because of loss of water, which was physically adsorbed on the wafer surfaces. The silicon wafers cleaned with the HF solution were hydrophobic. Their contact angle decreased in the atmosphere, while it increased in the vacuum up to 95 degrees. Gold thin films deposited on the hydrophilic wafers were smoother than that deposited on the hydrophobic wafers, because the numerous oxygen groups formed on the hydrophilic surfaces would react with gold adatoms in the sputtering process to form a continuous thin film at the nucleation stage. The argon, nitrogen, oxygen gas plasma treatments could change the silicon wafer surfaces from hydrophobic to hydrophilic by creating a thin (around 2.5 nm) silicon dioxide film, which could be utilized to improve the roughness and adhesion of the gold thin film. (C) 2014 Elsevier Ltd. All rights reserved.