Low Resistive TiO<sub>2</sub>Deposition by LPCVD Using TTIP and NbF<sub>5</sub>in Hydrogen-Ambient

• 作者: Kazuhiro Ishibashi Sakura Hatakeyama Satoshi Yamauchi
• 来源期刊: 结晶过程及技术期刊(英文)
• 学科: 医学
• 关键词: LPCVD-TiO2 H2-Ambient Nb and F Doping Low-Resistive TIO2 Optical Transmittance
• 年，卷（期）: 2015,（1）
• 页码范围: 15-23
• 页数: 9页
• 分类号: R73

摘要

Low resistive TiO2 layer was deposited by low pressure chemical vapor deposition (LPCVD) at pressure around 0.25 Pa using titanium-tetra-iso-propoxide (TTIP) and NbF5 in H2-ambient. Acti-vation energy for the deposition rate on the temperature was significantly decreased to 120 kJ/mol as compared with 228 kJ/mol for the deposition in H2 without NbF5. The deposition rate linearly increased with NbF5 supply rate but gradually decreased with H2 supply rate indicated that F on the deposition surface acts as catalyst for TTIP-dissociation but is non-activated by hydrogen. Resistivity of the layer was decreased by NbF5 supply depending on the deposition temperature with the activation energy of 319 kJ/mol, whereas the energy was 244 kJ/mol for the layer deposited in H2 without NbF5. The dependence of resistivity on NbF5. and H2 supply rates suggested that the doping should be performed by sufficient NbF5 and H2 supply rate to improve the crystallinity. As a result of the optimization, the resistivity was successfully reduced to 5 × 10-2 Ω·cm. Optical transmission spectra in UV-Vis region indicated that significant absorption observed for the layer deposited in H2 was notably decreased by using NbF5. The improved optical property was better than that for the layer deposited in O2-ambient.