The Thickness Dependence of Optical Constants of Ultrathin Iron Films

Abstract

Ultrathin iron films with different thicknesses from 7.1 to 51.7 nm are deposited by magnetron sputtering and covered by tantalum layers protecting them from being oxidized. These ultrathin iron films are studied by spectroscopic ellipsometry and transmittance measurement. An extra tantalum film is deposited under the same sputtering conditions and its optical constants and film thickness are obtained by a combination of ellipsometry and transmission measurement. After introducing these obtained optical constants and film thickness into the tantalum-iron film, the optical constants and film thicknesses of ultrathin iron films with different thicknesses are obtained. The results show that combining ellipsometry and transmission measurement improves the uniqueness of the obtained film thickness. The optical constants of ultrathin iron films depend strongly on film thicknesses. There is a broad absorption peak at about 370 nm and it shifts to 410 nm with film thickness decreasing.

Enhancing the Tunable Sensitivity of a Near-Ultraviolet to Visible to Near-Infrared Photo Irradiance Sensor Using an Indium Tin Oxide-Aluminum Oxide-Zirconia Aluminum Oxide-Silicon

“…These transmittance and resistivity results validate that annealing temperature optimizes the ITO film properties, in agreement with previous reports [26,27]. Overall, sample I2 processed with intermediate annealing displayed the best combined optical and electrical performance suitable for the photo irradiance sensor application [28,29].…”

Performance Comparison of SONOS-Type UV TD Sensor Using Indium Tin Oxide-Aluminum Oxide-Zirconia Aluminum Oxide-Silicon Oxide-Silicon and Indium Tin Oxide-Aluminum Oxide-Hafnium Aluminum Oxide-Silicon Oxide-Silicon

“…The comparison of UV transmittance and resistivity of ITO films at varying annealing temperatures is in line with findings from prior research studies [20]. [20][21][22][23][24]. Notably, the intensity of the (2,2,2) XRD diffraction peak of ITO films increases with the increase of post-anneal temperature.…”

“…The XRD analysis highlights the temperature-dependent crystallization of ITO films, as depicted in Figure 8. The peaks observed at around 2θ = 21.49°, 30.57°, and 51.00° correspond to the (2,1,1), (2,2,2), and (4,4,0) crystal structure planes of In2O3 [20][21][22][23][24]. Notably, the intensity of the (2,2,2) XRD diffraction peak of ITO films increases with the increase of post-anneal temperature.…”

Application of longitudinal generalized magneto-optical ellipsometry in magnetic ultrathin films

“…However, the spectroscopic ellipsometry measurements and data analysis are an established method for film thickness and optical constant determination. [9] The spectroscopic ellipsometry is used to determine the optical parameter [19] (Fig. 4) and the thickness of every layer in the samples.…”