Synthesis of Ti-Zr-V Non-Evaporable Getter Thin Films Grown on Al Alloy and CuCrZr Alloy

Abstract

The Ti-Zr-V non-evaporable getter (NEG) films were grown on Aluminum (Al) alloy and CuCrZr alloy, which can be used to fabricate the vacuum chambers in the ultra-high vacuum status. The Al alloy and CuCrZr alloy samples with different surface roughness were prepared by the different manufacturing methods. We studied whether the behavior and the microstructure of the Ti-Zr-V getter films are influence by the surface roughness of the substrate. The surface morphologies of Ti-Zr-V NEG films appear distinct and the growth of the films follows the nature of the substrate surface. The Ti-Zr-V films have nanocrystalline structures and the grain sizes of the films become slightly larger with increasing the surface smoothness. In addition, it was found that the reduction of the Ti-Zr-V NEG films to the metallic state was affected by presence of surface defects on the films. The surface defects should result from the existence of micro-pores, pockmarks, and micro-cracks on the original substrate, which produced from the manufacturing process.

Formation Mechanism of Passivation Layer under Air Exposure on TiZrV Non-Evaporable Getter Film

“…With prolonging the storage time under conditions set in this research, a significant change of the film surface layer has occurred: For the N 1s spectra, there were some amounts of N–H and AlN* were gradually formed apart from the moderate-screened γ-N 2 , well-screened γ-N 2 , and M-N For the C 1s spectra, C x H y − has undergone more significant changes in terms of structure and content compared to other carbonaceous compositions such as −COO–, − −CO–, ,, and carbides. , For the O 1s spectra, the content of oxides decreased greatly as C x H y increased significantly. For different metallic elemental p or d spectra, various kinds of oxides (TiO 2 , Ti 2 O 3 , ZrO 2 , and VO 2 ), hydroxyl groups (Ti-hydroxyl groups, Zr-hydroxyl groups, and V-hydroxyl groups), and carbides (TiC, ZrC*, and VC) were detected on the surface or in the surface layer of the film. …”

“…Regardless of the location of the test area (surface or cross-section), the carbon concentration showed an increasing trend with an increase in the aluminum foil wrapping storage time. (1) For the N 1s spectra, there were some amounts of N−H 57 and AlN* 58 were gradually formed apart from the moderate-screened γ-N 2 , 59 well-screened γ-N 2 , 59 and M-N. 60 (2) For the C 1s spectra, C x H y 61−63 has undergone more significant changes in terms of structure and content compared to other carbonaceous compositions such as −COO−, 64−66 −CO−, 16,17,31 and carbides. 30,67 (3) For the O 1s spectra, the content of oxides 30 decreased greatly as C x H y increased significantly.…”

“…However, different situations have also been discovered in the study of ZrV NEG films. , In O 1s for the surface layer of different types of NEGs, ,− ,− the signal of hydroxyl groups was observed apart from the strong peak of alloy oxides. The hydroxyl group was also reflected in the metal element p or d spectra, such as Zr 3d ,,, and Ni 2p . In C 1s, the main peak with a long tail on the left side is a common phenomenon observed on the metal surfaces.…”

Development and Characterization of Non-Evaporable Getter Thin Films with Ru Seeding Layer for MEMS Applications

“…As shown in Figure 3 a–c, the evolution with temperature of the XPS spectra associated with the Ti 2p orbital of the Ti upper-layer NEGs and the one associated with the Zr 3d orbital of the Zr upper-layer NEG have two regimes. In the first regime from the as-deposited NEG sample to the activation at 275 °C, the Ti 2p (Zr 3d) spectrum evolution was mainly controlled by the decrease of the doublet peak Ti 4+ (Zr 4+ ) of bending energy (BE): = 458.8 eV, = 182.8 eV related to the TiO 2 (ZrO 2 ) oxide, accompanied simultaneously with, both, an increase in the Ti x+<4 (Zr x+<4 ) doublet peaks related to TiO x<2 (ZrO x<2 ) suboxides [ 13 , 21 , 22 , 23 , 24 , 25 , 26 , 27 ] and an emergence of a metal hydroxide Ti(OH) 2 (Zr(OH) 2 ) doublet peak located at higher bending energies ( = 459.3 eV ( = 183.4 eV)) [ 28 , 29 , 30 , 31 ]. In the second regime, over 275 °C and up to 450 °C, the Ti 2p (Zr 3d) spectrum evolution was mainly controlled by a simultaneous decrease of metal-oxide, metal-hydroxide, and metal-suboxide, accompanied with a significant increase of doublet peak related to the metallic state Ti 0 (Zr 0 ) with a BE of = 454 ± 0.2 eV (BE of = 178.9 eV) as well as some contaminant-based phases peaks such as carbides TiC, TiC–O (ZrC, ZrC–O) [ 13 , 21 , 22 , 23 , 24 , 25 , 26 , 27 ].…”

“…It is to be noted that the metal-hydroxide (Ti(OH) 2 , Zr(OH) 2 ) XPS doublet peaks appeared after activating at 200 °C (see peak indexations on Figure 3 a–c). For the Ti upper-layer of Ti/Si and Ti/Ru/Si NEGs, the peak maximum level was reached also at 200 °C, with almost a small shift of the Ti 2p spectrum to a higher bending energy (BE = 459.4 eV) [ 28 , 29 ]. Whereas for the Zr upper-layer of the multilayered Zr/Ti/Ru/Si NEG, the peak maximum level was reached at an activation temperature of 275 °C, with a substantial shift of the Zr 3d spectrum towards a higher BE = 183.4 eV [ 27 , 30 , 31 ].…”