Low-Temperature Plasma-Assisted Atomic Layer Deposition of Silicon Nitride Moisture Permeation Barrier Layers
Low-Temperature Plasma-Assisted Atomic Layer Deposition of Silicon Nitride Moisture Permeation Barrier Layers
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DOI：
10.1021/acsami.5b06801
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发表时间：
2015-10-14
影响因子：
9.5
通讯作者：
Creatore, Mariadriana
中科院分区：
文献类型：
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作者：
Andringa, Anne-Marije;Perrotta, Alberto;Creatore, Mariadriana
需要对有机（光）电子器件（例如有机发光二极管（OLED）、光伏电池和场效应晶体管）进行封装，以使由湿气和氧气进入引起的器件劣化最小化。使用最近开发的低温等离子体辅助原子层沉积（ALD）方法已经制造了SiNx湿气渗透屏障，该方法由衬底与前体SiH 2（（NHBu）-Bu-t）（2）和与N-2馈送等离子体的半反应组成。沉积的薄膜已被其特征在于在其折射率和化学组成方面的光谱椭圆偏振法（SE），X射线光电子能谱（XPS），傅里叶变换红外光谱（FTIR）。SiNx薄膜的折射率范围为1.80至1.90的膜沉积在80摄氏度至200摄氏度，分别，和C，O，和H杂质水平降低时，沉积温度升高。通过多溶剂椭圆偏振孔隙率法（EP）研究了层的相对开孔率含量，采用具有不同动力学直径的三种溶剂：水（类似于0.3 nm）、乙醇（类似于0.4 nm）和甲苯（类似于0.6 nm）。无论沉积温度如何，以及因此SiNx膜中的杂质含量如何，都没有观察到任何吸附的吸收，这表明不存在直径大于0.3 nm的开孔。相反，多层发展已被观察到，导致II型等温线，根据IUPAC分类，是无孔层的特征。在20摄氏度和50%相对湿度的气候室中进行钙测试，以确定在120摄氏度下沉积的SiNx阻挡层的固有水蒸气透过率（WVTR）。在10（-6）g/m2/天范围内的固有WVTR值表明薄至10 nm的ALD SiNx层具有优异的阻挡性能，与厚度为几百纳米的现有技术等离子体增强化学气相沉积SiNx层的阻挡性能竞争。
Encapsulation of organic (opto-) electronic devices, such as organic light-emitting diodes (OLEDs), photovoltaic cells, and field-effect transistors, is required to minimize device degradation induced by moisture and oxygen ingress. SiNx moisture permeation barriers have been fabricated using a very recently developed low-temperature plasma-assisted atomic layer deposition (ALD) approach, consisting of half-reactions of the substrate with the precursor SiH2((NHBu)-Bu-t)(2) and with N-2-fed plasma. The deposited films have been characterized in terms of their refractive index and chemical composition by spectroscopic ellipsometry (SE), X-ray photoelectron spectroscopy (XPS), and Fourier-transform infrared spectroscopy (FTIR). The SiNx thin-film refractive index ranges from 1.80 to 1.90 for films deposited at 80 degrees C up to 200 degrees C, respectively, and the C, O, and H impurity levels decrease when the deposition temperature increases. The relative open porosity content of the layers has been studied by means of multisolvent ellipsometric porosimetry (EP), adopting three solvents with different kinetic diameters: water (similar to 0.3 nm), ethanol (similar to 0.4 nm), and toluene (similar to 0.6 nm). Irrespective of the deposition temperature, and hence the impurity content in the SiNx films, no uptake of any adsorptive has been observed, pointing to the absence of open pores larger than 0.3 nm in diameter. Instead, multilayer development has been observed, leading to type II isotherms that, according to the IUPAC classification, are characteristic of nonporous layers. The calcium test has been performed in a climate chamber at 20 degrees C and 50% relative humidity to determine the intrinsic water vapor transmission rate (WVTR) of SiNx barriers deposited at 120 degrees C. Intrinsic WVTR values in the range of 10(-6) g/m(2)/day indicate excellent barrier properties for ALD SiNx layers as thin as 10 nm, competing with that of state-of-the-art plasma-enhanced chemical vapor-deposited SiNx layers of a few hundred nanometers in thickness.