Low temperature aluminum nitride thin films for sensory applications
Low temperature aluminum nitride thin films for sensory applications
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DOI：
10.1063/1.4959895
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发表时间：
2016-07
期刊：
影响因子：
1.6
通讯作者：
E. Yarar;V. Hrkac;C. Zamponi;A. Piorra;L. Kienle;E. Quandt
中科院分区：
文献类型：
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作者：
E. Yarar;V. Hrkac;C. Zamponi;A. Piorra;L. Kienle;E. Quandt
介绍了一种低温溅射沉积法制备氮化铝（AlN）薄膜，该方法对温度预算有限的应用具有吸引力。研究了反应气体浓度、成核表面等离子体处理和薄膜厚度对AlN薄膜的微观结构、压电性能和介电性能的影响。观察到相对于增加的膜厚度的改进的晶体质量;其中AlN膜的半峰全宽（FWHM）从2.88 ± 0.16°下降到1.25 ± 0.07°，并且有效纵向压电系数（d33，f）对于在30 nm至2 μm范围内的膜厚度，从2.30 ± 0.32 pm/V增加至5.57 ± 0.34 pm/V。对于相同的厚度范围，介电损耗角（tan δ）从0.626% ± 0.005%降低到0.025% ± 0.011%。平均相对介电常数（er）计算为10.4 ± 0.05。一个几乎恒定的横向压电系数（|e31、f|在0.5 μm ~ 2 μm的范围内，测得样品的热膨胀系数为1.39 ± 0.01 C/m2。对薄膜（100 nm）和厚膜（1.6 μm）进行的透射电子显微镜（TEM）研究表明，AlN的成核和生长直接从AlN-Pt界面开始，与薄膜厚度无关，并表现出与在更高衬底温度下溅射的最新AlN薄膜相当的质量。
A low-temperature sputter deposition process for the synthesis of aluminum nitride (AlN) thin films that is attractive for applications with a limited temperature budget is presented. Influence of the reactive gas concentration, plasma treatment of the nucleation surface and film thickness on the microstructural, piezoelectric and dielectric properties of AlN is investigated. An improved crystal quality with respect to the increased film thickness was observed; where full width at half maximum (FWHM) of the AlN films decreased from 2.88 ± 0.16° down to 1.25 ± 0.07° and the effective longitudinal piezoelectric coefficient (d33,f) increased from 2.30 ± 0.32 pm/V up to 5.57 ± 0.34 pm/V for film thicknesses in the range of 30 nm to 2 μm. Dielectric loss angle (tan δ) decreased from 0.626% ± 0.005% to 0.025% ± 0.011% for the same thickness range. The average relative permittivity (er) was calculated as 10.4 ± 0.05. An almost constant transversal piezoelectric coefficient (|e31,f|) of 1.39 ± 0.01 C/m2 was measured for samples in the range of 0.5 μm to 2 μm. Transmission electron microscopy (TEM) investigations performed on thin (100 nm) and thick (1.6 μm) films revealed an (002) oriented AlN nucleation and growth starting directly from the AlN-Pt interface independent of the film thickness and exhibit comparable quality with the state-of-the-art AlN thin films sputtered at much higher substrate temperatures.