We investigated a fabrication technique of c‐plane‐oriented hydroxyapatite (HA) crystalline film on low‐cost amorphous SiO₂ substrates to apply the orientation‐controlled HA crystal to disposal biochips. An experiment was conducted by the pulsed laser deposition method. We showed that a high‐quality HA crystalline film was grown using a fluorapatite (FA) buffer layer, which was self‐oriented on amorphous SiO₂. A relationship between an FA‐film thickness and the HA quality was examined with an aim of minimizing a toxic risk of F to biomolecules, even if it was eluted from FA. It was found that the thickness of the FA film could be reduced to about 7.5 nm, at the same time, the crystallinity and smoothness of HA were also excellent. A crystal growth model of FA on the amorphous SiO₂ was also studied. We considered that highly reactive F in a laser‐ablated plume substituted for O on the substrate surface, which became a migration trap, causing three‐dimensional island growth as FA crystal nuclei. This model consistently agreed with a series of experimental results.

中文翻译：

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在无定形SiO2基底上制备c平面取向羟基磷灰石薄膜

我们研究了在低成本无定形SiO ₂基底上制备c平面取向羟基磷灰石（HA）晶体膜的技术，以将取向控制的HA晶体应用于处理生物芯片。通过脉冲激光沉积法进行了实验。我们表明，使用氟磷灰石（FA）缓冲层生长了高质量的HA结晶膜，该膜在无定形SiO ₂上自取向。检查了FA膜厚度与HA质量之间的关系，旨在最大程度地降低F对生物分子的毒性风险，即使F是从FA中洗脱出来的。发现FA膜的厚度可以减小到约7.5nm，同时，HA的结晶度和光滑度也优异。FA在非晶SiO上的晶体生长模型₂也进行了研究。我们认为，激光烧蚀羽流中的高反应性F替代了基底表面上的O，O变成了迁移陷阱，导致三维岛状生长为FA晶体核。该模型与一系列实验结果一致。