Green synthesis of novel in-situ micro/submicron-Cu paste for semiconductor interconnection

2022 ◽  
Author(s):  
Yu Zhang ◽  
Qiang Liu ◽  
Yu Liu ◽  
Jin Tong ◽  
Zhongwei Huang ◽  
...  

Abstract A green method for the synthesis of in-situ Cu paste is developed. Cu particles are prepared through chemical reduction by selecting a special copper source, reducing agent, and solvent. Then the reaction solution is directly concentrated to obtain an in-situ Cu paste. The synthesis of Cu particles and the preparation of Cu paste are conducted simultaneously, and the process of separation, purification, drying, storage, and re-dispersion of powder are reduced. Particles are not directly exposed to air, thus the oxidation of micro/nano-Cu is effectively prevented, and the agglomeration of particles caused by drying and dispersion operations is simultaneously reduced. Furthermore, the proposed method has a certain universality, and different types of Cu sources can be used to prepare in-situ paste with different sizes and morphologies. The entire preparation process is simple, efficient, green, and the yield can reach 99.99%, which breaks through the bottleneck of the application of traditional micro/nano-Cu materials. Copper acetate based in-situ paste is sintered for 30 min at 260 °C and 2 MPa in a reducing atmosphere. The shear strength, resistivity, and thermal conductivity reach 55.26 MPa, 4.01 × 10-8 Ω·m, and 92.75 W/(m·K), respectively, which could meet the interconnection application of power semiconductor devices.

Micromachines ◽  
2020 ◽  
Vol 11 (7) ◽  
pp. 626
Author(s):  
Sahin Demirci ◽  
Mehmet Can ◽  
Nurettin Sahiner

In this study, macroporous graphene aerogels (GAs) were synthesized by chemical reduction of graphene oxide sheets and were used as a support material for in situ synthesis of conductive poly(para-phenylenediamine) (p(p-PDA)). The in situ synthesis of p(p-PDA) in GA was carried out by using a simple oxidation polymerization technique. Moreover, the prepared conductive p(p-PDA) polymers in the networks of GAs were doped with various types of acids such as hydrochloric acid (HCl), nitric acid (HNO3), sulfuric acid (H2SO4), phosphoric acid (H3PO4), respectively. The prepared GA and different acid-doped forms as GA/p(p-PDA) composites were characterized by FT-IR, TGA, and conductivity measurements. The observed FT-IR peaks at 1574 cm−1, and 1491 cm−1, for stretching deformations of quinone and benzene, respectively, confirmed the in situ synthesis of P(p-PDA) polymers within GAs. The conductivity of GAs with 2.17 × 10−4 ± 3.15 × 10−5 S·cm−1 has experienced an approximately 250-fold increase to 5.16 × 10−2 ± 2.72 × 10−3 S·cm−1 after in situ synthesis of p(p-PDA) polymers and with HCl doping. Conductivity values for different types of acid-doped GA/p(p-PDA) composites were compared with the bare p(p-PDA) and their undoped forms. Moreover, the changes in the conductivity of GA and GA/p(p-PDA) composites upon CO2 gas exposure were compared and their sensory potential in terms of response and sensitivity, along with reusability in CO2 detection, were evaluated.


2014 ◽  
Vol 134 (6) ◽  
pp. 432-433
Author(s):  
Masahiro Sato ◽  
Akiko Kumada ◽  
Kunihiko Hidaka ◽  
Keisuke Yamashiro ◽  
Yuji Hayase ◽  
...  

2003 ◽  
Vol 781 ◽  
Author(s):  
J. Gray ◽  
W. Schwarzacher ◽  
X.D. Zhu

AbstractWe studied the initial stages of the electrodeposition of Pb in the presence of chlorine ions on Cu(100), using an oblique-incidence optical reflectivity difference (OIRD) technique. The OI-RD results reveal that immediately following the underpotential deposition (UPD) of the first Pb monolayer, two different types of bulk-phase films grow depending upon the magnitude of overpotential and cyclic voltammetry (CV) scan rate. At low overpotentials and/or slow scan rates, we propose that a bulk-phase Pb film grows on top of the UPD monolayer. At high overpotentials and/or fast scan rates, either a PbO, PbCl2, or a rough Pb bulk-phase layer grows on top of the UPD layer such that the reflectivity difference signal from such a film has an opposite sign.


Author(s):  
Ain Uddin ◽  
Weifan Sang ◽  
Yong Gao ◽  
Kyle Plunkett

The synthesis of poly(p-xylylene)s (PPXs) with sidechains containing alkyl bromide functionality, and their post-polymer modification, is described. The PPXs were prepared by a diimide hydrogenation of poly(p-phenylene vinylene)s (PPVs) that were originally synthesized by a Gilch polymerization. The polymer backbone reduction was carried out with hydrazine hydrate in toluene at 80 °C to provide polymers with the sidechain-containing bromide functionality intact. To demonstrate post-polymer modification of the sidechains, the resulting PPX polymers were modified with trimethylamine to form tetraalkylammonium ion functionality and were evaluated as anion conducting membranes. While PPX homopolymers containing tetralkylammonium ions were completely water soluble and not able to form valuable films, PPX copolymers containing mixed tetraalkylammonium ions and hydrophobic chains were capable of film formation and alkaline stability. In addition, an in situ crosslinking process that used N,N,N',N'-tetramethyl-1,6-hexanediamine during the tetraalkylammonium formation of brominated PPX polymers was also evaluated and gave reasonable films with conductivities of ~10 mS-cm-1.


2019 ◽  
Author(s):  
Ain Uddin ◽  
Weifan Sang ◽  
Yong Gao ◽  
Kyle Plunkett

The synthesis of poly(p-xylylene)s (PPXs) with sidechains containing alkyl bromide functionality, and their post-polymer modification, is described. The PPXs were prepared by a diimide hydrogenation of poly(p-phenylene vinylene)s (PPVs) that were originally synthesized by a Gilch polymerization. The polymer backbone reduction was carried out with hydrazine hydrate in toluene at 80 °C to provide polymers with the sidechain-containing bromide functionality intact. To demonstrate post-polymer modification of the sidechains, the resulting PPX polymers were modified with trimethylamine to form tetraalkylammonium ion functionality and were evaluated as anion conducting membranes. While PPX homopolymers containing tetralkylammonium ions were completely water soluble and not able to form valuable films, PPX copolymers containing mixed tetraalkylammonium ions and hydrophobic chains were capable of film formation and alkaline stability. In addition, an in situ crosslinking process that used N,N,N',N'-tetramethyl-1,6-hexanediamine during the tetraalkylammonium formation of brominated PPX polymers was also evaluated and gave reasonable films with conductivities of ~10 mS-cm-1.


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