Synthesis of Quaternary Ammonium Salts Based on Diketopyrrolopyrroles Skeletons and Their Applications in Copper Electroplating

Experimental and Theoretical Study of the New Leveler Basic Blue 1 during Copper Superconformal Growth

A novel chlorinated functional group-modified triphenylmethane derivative leveler BB1 is used to achieve superconformal electrodeposition in microvias. Cyclic voltammetry (CV) and electrochemical impedance spectroscopy (EIS) are performed to study the suppressing effect of BB1, while the convection-dependent adsorption of BB1 on the copper surface is analyzed by galvanostatic measurement, and a BB1 concentration window between 100 and 200 mg/L is beneficial for superfilling. The interactions among BB1, bis-(sodium sulfopropyl) disulfide (SPS), and poly(ethylene glycol) (PEG) are also investigated. Density functional theory (DFT) calculation and in situ Raman spectroscopy are coupled to study the suppression mechanism and synergistic suppression mechanism, namely, the adsorption effect between BB1 and copper substrate, as well as the coordination effect between the modified chlorinated functional group and Cu2+, is proposed. The copper layer becomes smoother and more compact with an increase in BB1 concentration, according to scanning electron microscopy (SEM) and atomic force microscopy (AFM), while X-ray diffraction (XRD) analysis shows that the introduction of BB1 is conducive to the formation of the copper (220) plane. Besides, the solution wettability is boosted by BB1. A copper interconnecting layer with high quality is achieved with 150 mg/L BB1, while the surface deposition thickness (SDT) is about 34 μm and filling percentages (FPs) for microvias with diameters of 100, 125, and 150 μm are 81.34, 82.72, and 81.39%, respectively.

Copolymer of Pyrrole and 1,4-Butanediol Diglycidyl as an Efficient Additive Leveler for Through-Hole Copper Electroplating

A copolymer comprising of pyrrole and 1,4-butanediol diglycidyl ether (PBDGE) was designed and synthesized as a leveler to improve the throwing power for printed circuit board (PCB) through-hole electroplating. The results of linear sweep voltammetry (LSV), galvanostatic measurements (GMs), and cyclic voltammetry (CV) reveal the strong coordination effect of PBDGE with other additives and confirm the advantageous performance of PBDGE to effectively assist the electroplating of through-hole. An increment of 35.5% in the throwing power was achieved under the addition of PBDGE in through-hole plating. Additionally, the reaction mechanism was studied by quantum chemical calculations and molecular dynamics (MD) simulations, indicating that the pyrrole rings of the PBDGE molecule are adsorbed on the copper surface as the adsorption sites to balance the copper plating regardless of the through-hole position differences.

Rh-Catalyzed tandem C-C/C-N bond formation of quinoxalines with alkynes leading to heterocyclic ammonium salts

An efficient Rh-catalyzed oxidative C-H activation/annulation of 2-arylquinoxalines with internal alkynes is described using Cu(OAc)2·H2O and AgBF4 to afford a diverse variety of substituted quarternary ammonium salts at room temperature. The mechanism of the protocol is established on the basis of isolation of the 5-membered rhodacycle intermediate and kinetic isotope studies. The mild reaction conditions, substrate scope and functional group diversity are the salient practical features.

4,6-Dimethyl-2-mercaptopyrimidine as a potential leveler for microvia filling with electroplating copper

Filling performance of microvia was defined as following equation: η = (A/B) × 100%.