In situ X-ray photoelectron spectroscopy study of gas cluster ion beam etching of FeCo film

Self Cite

The irradiation conditions of gas cluster ion beam (GCIB) for surface-activated bonding (SAB) were investigated. Since GCIB realizes bombardment with low energy (∼several eV/atom) and dense-energy deposition, it modifies the near-surface layer with low damage, which will be beneficial for surface-activated bonding. In this study, Cu–Cu bonding with GCIB irradiation was carried out as a preliminary study, and the irradiation conditions of Ar-GCIB were investigated. X-ray photoelectron spectroscopy (XPS) and contact angle measurements showed that the surface oxide on Cu was removed efficiently by oblique-incidence Ar-GCIB irradiations. Also, it was shown that sequential Ar-GCIB irradiations at normal and oblique incidences realized a smooth Cu surface. Cu–Cu bonding did not succeed for the pristine Cu or Cu irradiated with Ar monomer ions. In contrast, Cu–Cu bonding was realized with Ar-GCIB irradiation owing to surface oxide removal and smoothing effects.

Section: Experimental Methodsmentioning

confidence: 99%

Irradiation conditions of gas cluster ion beam for surface-activated bonding

Toyoda¹,

Sasaki²,

Ikeda³

et al. 2017

Self Cite

“…However, copper oxides with different oxidation states, such as cuprous oxide Cu One approach utilizes a gas-cluster beam under acetic acid vapor to etch Pt, Ru, Ta, CoFe, and other materials. [181][182][183][184][185] Another approach utilizes noble ion bombardment in a preadsorption step with subsequent exposure to reactants, followed by a removal step with volatile products, as shown in Fig. 10.…”

Section: Future Challengesmentioning

confidence: 99%

Progress and prospects in nanoscale dry processes: How can we control atomic layer reactions?

Ishikawa

Karahashi

Ichikı

et al. 2017

In this review, we discuss the progress of emerging dry processes for nanoscale fabrication. Experts in the fields of plasma processing have contributed to addressing the increasingly challenging demands in achieving atomic-level control of material selectivity and physicochemical reactions involving ion bombardment. The discussion encompasses major challenges shared across the plasma science and technology community. Focus is placed on advances in the development of fabrication technologies for emerging materials, especially metallic and intermetallic compounds and multiferroic, and two-dimensional (2D) materials, as well as state-of-the-art techniques used in nanoscale semiconductor manufacturing with a brief summary of future challenges.

“…On the other hand, the CuO layer was removed when acetic acid vapor was introduced during O 2 -GCIB irradiation. 20,21) We investigated more efficient SAB by introducing acetic acid vapor during GCIB irradiation. We have reported the efficient removal of surface oxide on metal surfaces such as Ni and Cu after Ar-GCIB irradiation with organic acid (acetic acid or acetyl-acetone).…”

Section: Introductionmentioning

confidence: 99%

Surface preparation of metal films by gas cluster ion beams using organic acid vapor for Cu–Cu bonding

Hanahara

Takeuchi

Toyoda

2022

Surface activated bonding of Cu by gas cluster ion beam (GCIB) irradiation with acetic acid vapor was studied. GCIB irradiation realizes surface smoothing and surface reaction enhancement without severe damage. Therefore, it is promising for surface-activated bonding (SAB). In this study, acetic acid vapor was introduced during Ar-GCIB irradiation to assist removal of surface oxides on Cu surface. XPS results showed that Cu(OH)2 was effectively removed by reaction with adsorbed acetic acid, and there was no residue by acetic acid adsorption. In addition, surface roughness decreased by Ar-GCIB irradiation with acetic acid because of the preferential removal of protrusion. Preliminary bonding experiments showed increase of Cu-Cu bond strength by Ar-GCIB irradiation with acetic acid vapor.