Residual stress of glass and crystalline oxide thin films responding to humidity

Author:

Nishimura Yuki1,Ohta Yuma1,Boll Felix23ORCID,Cop Pascal23ORCID,Smarsly Bernd23ORCID,Kozuka Hiromitsu1ORCID

Affiliation:

1. Department of Chemistry and Materials Engineering, Kansai University, Suita 564-8680, Japan

2. Physikalisch-Chemisches Institut, Justus Liebig University, Heinrich-Buff-Ring 17, 35392 Giessen, Germany

3. Center of Materials Research, Justus Liebig University, Heinrich-Buff-Ring 16, 35392 Giessen, Germany

Abstract

Here, we demonstrate that oxide thin film devices could be affected by humidity in their in-plane stress and in substrate curvature. We prepared silica glass and ceria crystalline thin films on Si(100) wafers by the sol-gel method. Both films had “tensile” in-plane residual stress. We cycled the relative humidity between ca. 20% and 80% in the square wave and monitored the substrate curvature in situ, from which in-plane stress was calculated. The increase and decrease in humidity resulted in a decrease and an increase in tensile stress, respectively. In situ ellipsometric measurements during humidity cycles showed that both thickness and refractive index increase and decrease on the increase and decrease in humidity, respectively. This guarantees that the volume expansion and shrinkage caused by water molecule adsorption/absorption and desorption, respectively, are the origins of the response of the stress to humidity. Responding to the change in humidity, thicker silica glass films with low porosities of 1%–3% showed more sluggish change in stress, suggesting absorption/desorption of water via diffusion in siloxane network in such dense films. Silica glass films with a larger porosity showed more quick response to humidity, indicating adsorption/desorption on the pore wall as the primary cause of the response. “Compressive” stress in a silica glass film with ca. 1% porosity exhibited very slight response in stress to humidity, which was attributed to the hard diffusion of water in compressed siloxane network.

Funder

Japan Society for the Promotion of Science

Nippon Sheet Glass Foundation for Materials Science and Engineering

Publisher

AIP Publishing

Subject

Physics and Astronomy (miscellaneous)

同舟云学术

1.学者识别学者识别

2.学术分析学术分析

3.人才评估人才评估

"同舟云学术"是以全球学者为主线,采集、加工和组织学术论文而形成的新型学术文献查询和分析系统,可以对全球学者进行文献检索和人才价值评估。用户可以通过关注某些学科领域的顶尖人物而持续追踪该领域的学科进展和研究前沿。经过近期的数据扩容,当前同舟云学术共收录了国内外主流学术期刊6万余种,收集的期刊论文及会议论文总量共计约1.5亿篇,并以每天添加12000余篇中外论文的速度递增。我们也可以为用户提供个性化、定制化的学者数据。欢迎来电咨询!咨询电话:010-8811{复制后删除}0370

www.globalauthorid.com

TOP

Copyright © 2019-2024 北京同舟云网络信息技术有限公司
京公网安备11010802033243号  京ICP备18003416号-3