Wet Etching of Amorphous TiO2 Thin Films Using H3PO4--H2O2 Aqueous Solution

We report on the wet etching of amorphous undoped and Nb-doped TiO 2 thin films using H 3 PO 4 --H 2 O 2 etching solution. The etching rate ($R$) showed a maximum at a H 3 PO 4 concentration of approximately 50 wt % at 80 °C, suggesting that H 2 PO 4 - and/or H 3 O + is responsible for the etching r...

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Published inJpn J Appl Phys Vol. 52; no. 9; pp. 098002 - 098002-3
Main Authors Okazaki, Sohei, Ohhashi, Takuya, Nakao, Shoichiro, Hirose, Yasushi, Hitosugi, Taro, Hasegawa, Tetsuya
Format Journal Article
LanguageEnglish
Published The Japan Society of Applied Physics 01.09.2013
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Summary:We report on the wet etching of amorphous undoped and Nb-doped TiO 2 thin films using H 3 PO 4 --H 2 O 2 etching solution. The etching rate ($R$) showed a maximum at a H 3 PO 4 concentration of approximately 50 wt % at 80 °C, suggesting that H 2 PO 4 - and/or H 3 O + is responsible for the etching reaction. The addition of H 2 O 2 to H 3 PO 4 solution significantly enhanced $R$, and an optimized solution exhibited an $R$ of 13 nm/min at 80 °C, which is one order of magnitude higher than that using H 2 SO 4 . These results demonstrate that H 3 PO 4 --H 2 O 2 aqueous solution is an effective etchant for TiO 2 -based amorphous thin films.
Bibliography:Etching rate of amorphous TiO 2 thin film in H 3 PO 4 aqueous solution at 80 °C as a function of H 3 PO 4 concentration. Etching rate of amorphous TNO thin film in 85 wt % H 3 PO 4 aqueous solution plotted against the inverse of solution temperature ($1/T$). The dashed line represents the least-squares fit to the Arrhenius equation. Etching rate of TNO thin film in H 3 PO 4 --H 2 O 2 solution at 80 °C as a function of H 2 O 2 concentration. The concentration of H 3 PO 4 was kept at 50 wt %.
ISSN:0021-4922
1347-4065
DOI:10.7567/JJAP.52.098002