Minkov Dorian, Angelov George, Nestorov Radi, Nezhdanov Aleksey, Usanov Dmitry, Kudryashov Mikhail, Mashin Aleksandr
College of Energy and Electronics, Technical University of Sofia, 2140 Botevgrad, Bulgaria.
Department of Microelectronics, Technical University of Sofia, 1000 Sofia, Bulgaria.
Materials (Basel). 2020 Jul 3;13(13):2981. doi: 10.3390/ma13132981.
Three AsTe films with different x and dissimilar average thickness are characterized mainly from one interference transmittance spectrum ( = 300 to 3000 nm) of such film on a substrate based on the advanced optimizing envelope method (AOEM). A simple dual transformation of () is proposed and used for increasing the accuracy of computation of its envelopes () and () accounting for the significant glass substrate absorption especially for > 2500 nm. The refractive index () of AsTe and AsTe films is determined with a relative error <0.30%. As far as we know, the AsTe film is the only one with anomalous dispersion and the thickest, with estimated = 1.1446 nm, ever characterized by an envelope method. It is also shown and explained why the extinction coefficient () of any of the three AsTe films is computed more accurately from the quantity () = [()()] compared to its commonly employed computation from (). The obtained results strengthen our conviction that the AOEM has a capacity for providing most accurate optical characterization of almost every dielectric or semiconductor film with > 300 nm on a substrate, compared to all the other methods for characterization of such films only from ().
基于先进优化包络法（AOEM），通过对衬底上此类薄膜的一个干涉透射光谱（波长范围为300至3000纳米）进行分析，对三种具有不同x值和不同平均厚度的AsTe薄膜进行了主要表征。提出并使用了一种简单的对透射率（）的双重变换，以提高其包络线（）和（）计算的准确性，尤其是考虑到玻璃衬底在波长大于2500纳米时的显著吸收。AsTe和AsTe薄膜的折射率（）测定的相对误差小于0.30%。据我们所知，AsTe薄膜是唯一一种具有反常色散且最厚的薄膜，其估算厚度为1.1446纳米，是通过包络法表征的。文中还展示并解释了为什么与通常从（）计算相比，从量（） = [（）（）]计算三种AsTe薄膜中任何一种的消光系数（）更为准确。所得结果强化了我们的信念，即与仅从（）表征此类薄膜的所有其他方法相比，AOEM能够为衬底上几乎每一种波长大于300纳米的介电或半导体薄膜提供最准确的光学表征。
