On the Properties of Nanoporous SiO2 Films for Single Layer Antireflection Coating
On the Properties of Nanoporous SiO2 Films for Single Layer Antireflection Coating
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DOI：
10.1002/adem.201801229
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发表时间：
2019-06-01
影响因子：
3.6
通讯作者：
Szeghalmi, Adriana
中科院分区：
文献类型：
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作者：
Ghazaryan, Lilit;Sekman, Yusuf;Szeghalmi, Adriana
通过对原子层沉积(ALD)Al_2O_3：SiO_2复合薄膜的选择性化学腐蚀，制备了由纳米孔SiO_2薄膜组成的单层增透膜(SLAR)。通过在复合材料中施加适当的比例，最终得到的NP-SiO_2薄膜的反射率在600 nm处从1.132微调到1.400。为了满足SLAR涂层从深紫外(DUV)到近红外(NIR)光谱范围的要求，通过ALD工艺对薄膜厚度进行了纳米级的控制。SLAR可同时应用于平面或高度弯曲基板的两侧。在熔融二氧化硅衬底上，即使在193 nm波长下也能获得99.4%以上的透过率。不同的表征方法证明了这些SLAR在杂质、光学损耗、激光损伤阈值(LIDT)和表面超亲水性方面的优势。由激光诱导偏转测量确定的193 nm波长的吸收损耗约为200ppm，在1064 nm波长的吸收损耗约为2ppm，而对于四分之一波长层，在532 nm波长的散射损耗约为30ppm。在1064 nm处的LIDT值在93J cm(-2)范围内，与未镀膜衬底上的测量值接近。
Single layer antireflection coatings (SLAR) consisting of nanoporous silica (NP SiO2) films are developed by selective chemical etching of atomic layer deposited (ALD) Al2O3:SiO2 composite films. The reflective index of the final NP SiO2 film is finely adjusted from 1.132 to 1.400 at 600 nm wavelength by applying an appropriate ratio in the composite. To meet the requirements of the SLAR coatings from the deep UV (DUV) to the near IR (NIR) spectral range, the film thickness is controlled with nanometer precision by the ALD process. The SLAR are simultaneously applied on both sides of flat or highly curved substrates. Transmittance values above 99.4% are achieved even at a wavelength of 193 nm on fused silica substrates. Various characterization methods demonstrate the advantages of these SLAR with regard to impurities, optical losses, laser induced damage threshold (LIDT) properties, and surface super-hydrophilicity. The absorption losses at 193 nm wavelength as determined by laser induced deflection measurements amount to approximately 200 ppm, and to approximately 2 ppm at a wavelength of 1064 nm, while the scattering losses are around 30 ppm at 532 nm wavelength for quarter-wave layers. The LIDT values at 1064 nm are in the range of 93 J cm(-2) being close to the values measured on the uncoated substrate.