Nanoscale chemical etching of near-stoichiometric lithium tantalate

• Published in: Journal of applied physics 2005-03, Vol.97 (6), p.064308-064308-4
• Main Authors: Liu, Xiaoyan, Terabe, Kazuya, Nakamura, Masaru, Takekawa, Shunji, Kitamura, Kenji
• Format: Article
• Language: English
• ISSN: 0021-8979; 1089-7550
• DOI: 10.1063/1.1870115

The chemical etching properties of ferroelectric Li Ta O 3 crystal in near-stoichiometric compositions were quantitatively investigated with various ratios of HF and H N O 3 acid mixtures by scanning force microscopy in the nanoscale range. Along with congruent Li Ta O 3 crystal, the − Z surfaces of near-stoichiometric Li Ta O 3 crystal were etched preferentially with pure HF acid and mixtures of HF and H N O 3 acids. The etching rates on the − Z surface of near-stoichiometric Li Ta O 3 crystal were slower than that of congruent Li Ta O 3 crystal. The roughness (peak to peak) of etched surfaces were about 2 nm after being etched in all ratios of HF and H N O 3 acids to a 70 - nm etch depth. The temperature dependence of the etch rate followed the Arrhenius law. By taking advantage of the chemical preferential etching properties, precision surface structures could be fabricated on near-stoichiometric Li Ta O 3 crystal.