Silicon wafer wettability and aging behaviors: Impact on gold thin-film morphology

Handle URI:
http://hdl.handle.net/10754/563767
Title:
Silicon wafer wettability and aging behaviors: Impact on gold thin-film morphology
Authors:
Yang, Xiaoming; Zhong, Zhaowei; Diallo, Elhadj; Wang, Zhihong; Yue, Weisheng
Abstract:
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 (H2O 2, 30%), 120 °C), SC1 (1:1:5 mixture of NH4OH, H 2O2 and H2O, at 80°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°. 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°. 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. © 2014 Elsevier Ltd. All rights reserved.
KAUST Department:
Advanced Nanofabrication, Imaging and Characterization Core Lab; Core Labs
Publisher:
Elsevier BV
Journal:
Materials Science in Semiconductor Processing
Issue Date:
Oct-2014
DOI:
10.1016/j.mssp.2014.03.044
Type:
Article
ISSN:
13698001
Appears in Collections:
Articles; Advanced Nanofabrication, Imaging and Characterization Core Lab

Full metadata record

DC FieldValue Language
dc.contributor.authorYang, Xiaomingen
dc.contributor.authorZhong, Zhaoweien
dc.contributor.authorDiallo, Elhadjen
dc.contributor.authorWang, Zhihongen
dc.contributor.authorYue, Weishengen
dc.date.accessioned2015-08-03T12:09:28Zen
dc.date.available2015-08-03T12:09:28Zen
dc.date.issued2014-10en
dc.identifier.issn13698001en
dc.identifier.doi10.1016/j.mssp.2014.03.044en
dc.identifier.urihttp://hdl.handle.net/10754/563767en
dc.description.abstractThis 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 (H2O 2, 30%), 120 °C), SC1 (1:1:5 mixture of NH4OH, H 2O2 and H2O, at 80°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°. 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°. 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. © 2014 Elsevier Ltd. All rights reserved.en
dc.publisherElsevier BVen
dc.subjectGold thin filmen
dc.subjectPlasma treatmenten
dc.subjectRoughnessen
dc.subjectSilicon waferen
dc.subjectWettabilityen
dc.titleSilicon wafer wettability and aging behaviors: Impact on gold thin-film morphologyen
dc.typeArticleen
dc.contributor.departmentAdvanced Nanofabrication, Imaging and Characterization Core Laben
dc.contributor.departmentCore Labsen
dc.identifier.journalMaterials Science in Semiconductor Processingen
dc.contributor.institutionSchool of Mechanical and Aerospace Engineering, Nanyang Technological University, 50 Nanyang Avenue, Singapore, Singaporeen
kaust.authorDiallo, Elhadjen
kaust.authorWang, Zhihongen
kaust.authorYue, Weishengen
kaust.authorYang, Xiaomingen
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