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

Abstract

A series of DPP derivatives bearing quaternary ammonium salt centers with different lengths of carbon chains have been designed and synthesized. Their inhibition actions on copper electroplating were first investigated. A total of four diketopyrrolopyrrole (DPP) derivatives showed different inhibition capabilities on copper electroplating. To investigate interactions between metal surface and additives, we used quantum chemical calculations. Static and dynamic surface tension of four DPP derivatives had been measured, and the results showed DPP-10C (1c) with a faster-decreasing rate of dynamic surface tension among the four derivatives, which indicated higher adsorption rate of additive on the cathode surface and gives rise to stronger inhibiting effect of copper electrodeposition. Then, DPP-10C (1c) as the representative additive, was selected for the systematic study of the leveling influence during microvia filling through comprehensive electroplating tests. In addition, field-emission scanning electron microscope images and X-ray diffraction results showed the surface morphology, which indicated that addition of DPP derivative (1c) could lead a fine copper deposit and cause the preferential orientations of copper deposits to change from [220] to [111], which happened in particular at higher concentrations.

Fatty Acid Quaternary Ammonium Surfactants Based on Renewable Resources as a Leveler for Copper Electroplating

“…Hence, the surfactivity of additives were closely related to the ability of inhibiting copper electrodeposition. Our previous study has shown that the compound with the lowest surface tension indicated the strongest inhibition of copper electrodeposition . Compared with the lowest surface tension (47.1 m Nm −1 ) of the DPP‐based quaternary ammonium salt in our previous work, the lowest surface tension of the compound 1 e reached 19.7 m Nm −1 .…”

“…During the practical plating process, the new liquid‐solid interface is constantly forming and the surface tension is never balanced . An inhibition effect of additive molecules was required to reach the liquid‐solid interface on copper electrodeposition .…”

“…The quaternary ammonium salts, being proved as effective levelling agent, have been widely reported . During the electrodeposition process, the cationic quaternary ammoniums ionized in aqueous solution could easily reach to the cathode surface and adsorb to suppress copper electrodeposition process .…”

“…[15] The quaternary ammonium salts, being proved as effective levelling agent, have been widely reported. [11,[16][17][18] During the electrodeposition process, the cationic quaternary ammoniums ionized in aqueous solution could easily reach to the cathode surface and adsorb to suppress copper electrodeposition process. [17] The quaternary ammonium salts based on fatty acids derived from vegetable oil are extensively applied in food chemistry, pharmaceuticals, and other industries.…”

“…[11,[16][17][18] During the electrodeposition process, the cationic quaternary ammoniums ionized in aqueous solution could easily reach to the cathode surface and adsorb to suppress copper electrodeposition process. [17] The quaternary ammonium salts based on fatty acids derived from vegetable oil are extensively applied in food chemistry, pharmaceuticals, and other industries. [19] Moreover, as they derived from renewable resources, they have some advantages, such as easily biodegradable, economically feasible, and environmentally friendly.…”