Effects of Vacuum Ultraviolet Surface Treatment on the Bonding Interconnections for Flip Chip and 3-D Integration

Sakuma, Katsuyuki; Mizuno, Jun; Nagai, Noriyasu; Unami, Naoko; Shoji, Shuichi

doi:10.1109/tepm.2010.2048917

Cited by 19 publications

(4 citation statements)

References 13 publications

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“…All these VUV photochemically generated active oxygen species (VUV-O) are highly oxidative to organics. Photochemical processing by using VUV-O has been demonstrated to be a powerful method for modifying and patterning organic surfaces, such as polymers − and self-assembled monolayers (SAMs). − The precursor to rGO, i.e., GO, can be regarded as a kind of organic materials and it is promising to utilize locally generated VUV-O for the photoetching of GO.…”

Section: Introductionmentioning

confidence: 99%

Vacuum-Ultraviolet Promoted Oxidative Micro Photoetching of Graphene Oxide

Utsunomiya

Ichii

et al. 2016

ACS Appl. Mater. Interfaces

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Microprocessing of graphene oxide (GO) films is of fundamental importance in fabricating graphene-based devices. We demonstrate the photoetching of GO sheets using vacuum-ultraviolet (VUV, λ = 172 nm) light under controlled atmospheric pressure. X-ray photoelectron spectroscopy (XPS), atomic force microscopy (AFM) and differential interference contrast microscopy (DIC) studies revealed that the photoetching of GO films successfully proceeded in the regions exposed to VUV irradiation in the oxygen-containing atmosphere. Precise photoetching of the GO sheets was achieved at a vacuum pressure of 5 × 10(3) Pa with VUV light irradiation for 20 min. This was followed by VUV irradiation in a high vacuum (<10(-3) Pa) and sonication in water. The photoetched GO sheets then transformed into reduced GO (rGO) patterns. The minimum feature fabricated by this method was 2 μm wide lines aligned at an interval of 4 μm. This method provides a cost-effective way to fabricate rGO patterns with fewer boundaries between rGO sheets and offers a better integrity of rGO, which can be promising for further applications in micro mechanics, micro electrochemistry, optoelectronics, etc.

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Section: Introductionmentioning

confidence: 99%

Vacuum-Ultraviolet Promoted Oxidative Micro Photoetching of Graphene Oxide

Utsunomiya

Ichii

et al. 2016

ACS Appl. Mater. Interfaces

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“…The excited oxygen also aids in breaking the chemical bonds quickly and efficiently. 28 The major advantage of using VUV pretreatment compared to majority of other surface treatments is that VUV surface treatment being a photochemical oxidation technique avoids direct contact of the plasma with the sample surface, reducing the damage caused through etching of carbon atoms and at the same time maintains the primary advantage of plasma functionalization being solvent-free dry process. On the other hand, other oxidation pretreatment techniques can extensively damage the structural integrity and signicantly modify the electrode morphology due to exposure to high-energy species such as electrons or ions, oen generated in discharge plasmas.…”

Section: Resultsmentioning

confidence: 99%

Functionalized carbon microarrays platform for high sensitive detection of HIV-Tat peptide

et al. 2015

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“…The O(1D) decomposes any organic matter on the sample surfaces [1,14]. The O(1D) decomposes any organic matter on the sample surfaces [1,14].…”

Section: Methodsmentioning

confidence: 99%

Fluxless Bonding Using Vacuum Ultraviolet and Formic Acid for 3D Interconnects

et al. 2010

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We have developed a novel surface treatment process using vacuum ultraviolet (VUV) light with a wavelength of 172 nm and formic acid vapor. A previous study showed that the VUV process can help remove the organic contaminants on the bonding surfaces and improve the shear strength [1]. This new work focuses on studying the effects of VUV/O 3 and formic acid treatments. The formic acid (HCOOH) vapor removes the metal oxides from the surfaces before the bonding process. Evaporated Cu/Sn and immersion Au were used for the bonding microbumps and bonding pads in our evaluations. Different cleaning conditions with VUV/O 3 , formic acid vapor, or both were compared and evaluated. X-ray Photoelectron Spectroscopy (XPS) was used to study the surface elemental composition of the micro-bumps and pad surfaces before and after the cleaning process. The photoelectron spectra of C1s, Sn3d, and Au4f were obtained with XPS. The XPS results showed the atomic carbon concentrations were significantly decreased by the VUV/O 3 treatment process, while the Sn and Au concentrations were increased by the VUV/O 3 and formic acid treatment because of the removal of the organic contaminants and metal oxides from the surfaces. The bonding strength of the Cu/Sn bumps was evaluated using a shear test tool. The results shows that the combination of VUV/O 3 and formic acid treatment obtains the highest average shear strength among the treatments tested, with a shear strength almost 2.5 times stronger than the untreated samples.

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Effects of Vacuum Ultraviolet Surface Treatment on the Bonding Interconnections for Flip Chip and 3-D Integration

Cited by 19 publications

References 13 publications

Vacuum-Ultraviolet Promoted Oxidative Micro Photoetching of Graphene Oxide

Vacuum-Ultraviolet Promoted Oxidative Micro Photoetching of Graphene Oxide

Functionalized carbon microarrays platform for high sensitive detection of HIV-Tat peptide

Fluxless Bonding Using Vacuum Ultraviolet and Formic Acid for 3D Interconnects

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