Abstract

Crystalline or glass oxide thin films with thickness of ca. 50–210 nm and porosity of ca. 5–17% were prepared on Si(100) wafers by the sol–gel method. The films were left standing at room temperature in dry and humid atmosphere as well as in water for varying periods of time. We measured the in-plane residual stress of the films as a function of time during storing at room temperature by measuring the radius of curvature of the substrate surface. The anatase, silica, and ceria films had tensile in-plane residual stress when fired at 1000 °C, 600 °C, and 800 °C, respectively. Such tensile stress was found to decrease with time, finally becoming constant, at room temperature, where the rate and extent of stress reduction were larger in the order, “in water” > “in humid atmosphere” > “in dry atmosphere.” On the other hand, the silica films had compressive in-plane residual stress when fired at 1000 °C. Such compressive stress was stable, not decreasing with time, at room temperature. The ceria film, after showing a decrease in tensile stress in humid atmosphere, exhibited an increase in stress when heated at 300 °C. When stored again at room temperature in humid atmosphere, the film showed a decrease in stress with time over again. Then we excluded the structural relaxation as the origin of the tensile stress reduction at room temperature, considering the stability of the compressive stress and the reversibility of the tensile stress. The ceria films showed a decrease in tensile stress even when stored in acetone and n-heptane vapors, suggesting that the film expansion resulting from the vapor-molecule adsorption may be the origin of the decrease in tensile stress. Yttria-stabilized zirconia films fired at 1000 °C also had tensile stress. The stress, however, was constant with time at room temperature, the reason for which is unknown, and further studies should be made.

中文翻译：

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溶胶-凝胶衍生的晶体和玻璃氧化物薄膜的面内残余应力明显松弛

摘要

晶体或玻璃氧化物薄膜，厚度约为。50-210 nm，孔隙率约 通过溶胶-凝胶法在Si（100）晶片上制备了5-17％。将膜在干燥和潮湿的环境以及水中在室温下放置不同的时间。我们通过测量基材表面的曲率半径，测量了在室温下储存过程中薄膜的面内残余应力与时间的关系。当分别在1000°C，600°C和800°C焙烧时，锐钛矿，二氧化硅和二氧化铈薄膜具有拉伸的面内残余应力。发现这种拉伸应力随时间减小，最终在室温下保持恒定，在该温度下，应力减小的速率和程度依次依次为“在水中”>“在潮湿环境中”>“在干燥气氛中”。另一方面，当在1000°C下烧制时，二氧化硅膜具有压缩面内残余应力。这种压缩应力在室温下是稳定的，并且不会随时间降低。氧化铈膜在潮湿气氛中拉伸应力减小后，在300℃下加热时，应力增大。当再次在室温下在潮湿的气氛中存储时，该膜显示出应力随着时间的推移而再次降低。然后，考虑到压缩应力的稳定性和拉伸应力的可逆性，我们将结构松弛作为室温拉伸应力降低的起源。氧化铈薄膜即使存储在丙酮和 氧化铈膜在潮湿气氛中拉伸应力减小后，在300℃下加热时，应力增大。当再次在室温下在潮湿的气氛中存储时，该膜显示出应力随着时间的推移而再次降低。然后，考虑到压缩应力的稳定性和拉伸应力的可逆性，我们将结构松弛作为室温拉伸应力降低的起源。二氧化铈薄膜即使存储在丙酮和 氧化铈膜在潮湿气氛中拉伸应力减小后，在300℃下加热时，应力增大。当再次在室温下在潮湿的气氛中存储时，该膜显示出应力随着时间的推移而再次降低。然后，考虑到压缩应力的稳定性和拉伸应力的可逆性，我们将结构松弛作为室温拉伸应力降低的起源。氧化铈薄膜即使存储在丙酮和 然后，考虑到压缩应力的稳定性和拉伸应力的可逆性，我们将结构松弛作为室温拉伸应力降低的起源。氧化铈薄膜即使存储在丙酮和 然后，考虑到压缩应力的稳定性和拉伸应力的可逆性，我们将结构松弛作为室温拉伸应力降低的起源。氧化铈薄膜即使存储在丙酮和正庚烷蒸气，表明由蒸气分子吸附引起的薄膜膨胀可能是拉伸应力降低的原因。在1000°C下烧成的氧化钇稳定的氧化锆薄膜也具有拉应力。然而，应力在室温下随时间是恒定的，其原因尚不清楚，应进一步研究。