Vacuum ultraviolet thin films 1: Optical constants of BaF_2, CaF_2, LaF_3, MgF_2, Al_2O_3, HfO_2, and SiO_2 thin films

Abstract

The optical constants of MgF(2) (bulk) and BaF(2), CaF(2), LaF(3), MgF(2), Al(2)O(3), HfO(2), and SiO(2) films deposited on MgF(2) substrates are determined from photometric measurements through an iteration process of matching calculated and measured values of the reflectance and transmittance in the 120-230-nm vacuum ultraviolet wavelength region. The potential use of the listed fluorides and oxides as vacuum ultraviolet coating materials is discussed in part 2 of this paper.

Ultraviolet antireflection coatings for use in silicon detector design

“…The returned values confirmed the expected behavior of all films, except HfO 2 . We found the index of refraction below 250 nm was much higher than that measured [19,20] (maximum difference of 30%). Values for k were as expected.…”

“…There are several published indices of refraction for the Si substrate, which contributes to some uncertainty in the predicted reflectance. The indices of refraction for all materials were taken from Palik [17,18], except for HfO 2 , which came from Zukic et al [19,20]. An alternative index of refraction for Si was also consulted, taken from Philipp and Taft [21].…”

Atomic Layer Deposition of LaF3 Thin Films using La(thd)3 and TiF4 as Precursors

“…LaF 3 thin films exhibit extremely good moisture resistance, therefore they are very useful, e.g., for protecting optical components. [3] Due to its high band-gap and refractive index, higher than those of the other VUV transparent films, LaF 3 is a useful material for VUV optics, particularly for constructing a high-low refractive index pair with, e.g., MgF 2 [4][5][6][7][8][9][10][11][12][13] as the low refractive index material. AlF 3 has also been used together with LaF 3 in optical multilayer structures.…”

Characterization of LaF3 coatings prepared at different temperatures and rates

“…LaF 3 is considered as the best choice for high index material in UV region, especially DUV region [5,6]. The HR coating comprising LaF 3 as high index material possesses excellent UV laser damage resistance [7,8].…”