Effects of 2,2-Dithiodipyridine as a Leveler for Through-Holes Filling by Copper Electroplating

Abstract

2,2-dithiodipyridine (DTDP), a low molecular weight nitrogen-containing heterocyclic compound with a disulfide bond, is added as a novel leveler to the plating solution to achieve the void-free filling of through-holes (THs) by butterfly technology (BFT). Herein, quantum chemical calculation and molecular dynamics (MD) simulation theoretically manifest that DTDP can adsorb on the copper surface through its plentiful active sites and strong adsorption capacity, which can provide theoretical support for DTDP as a leveler. Not only that, the test results of scanning electron microscopy (SEM), atomic force microscopy (AFM), X-ray photoelectron spectroscopy (XPS) and electrochemical measurements further confirm that DTDP can form an adsorption film on the copper surface, which not only improves the surface morphology of copper, but also increases the cathodic polarization, resulting in the inhibition of copper deposition. Remarkably, under the synergistic effects of various additives, the perfect filling performance of THs can be achieved by adding a proper concentration of DTDP to the electroplating solution. Combined with all the test results, the conjecture of DTDP as a potential leveler of THs filling by copper electroplating is confirmed.

Strong Convection-Dependent Adsorption of Phenothiazine Skeleton Levelers and Their Application in Copper Electroplating

“…Meanwhile, a pattern reaction for the synthesis of levelers has not yet emerged. Design and synthesis of levelers are time-consuming, so the study of the structure–property of levelers is of great significance. ,, A previous study reported diketopyrrolopyrrole (DPP)-based levelers which have a fully conjugated, highly stable, and rigid planar structure . A DPP-based leveler with a four-ring-fused skeleton is an excellent substrate that could firmly anchor on the copper surface and optimize the deposition behavior.…”

“…15−17 property of levelers is of great significance. 10,18,19 A previous study reported diketopyrrolopyrrole (DPP)-based levelers which have a fully conjugated, highly stable, and rigid planar structure. 15 A DPP-based leveler with a four-ring-fused skeleton is an excellent substrate that could firmly anchor on the copper surface and optimize the deposition behavior.…”

Detection of Organic Additives in Copper Plating Bath Using Voltammetric Methods That Involve a Screen-printed Nano-Au Electrode

“…The organic additives consist of accelerators [2][3], suppressors [4][5] and levelers [6][7]. Three types of organic additives enhance chemical reactions, improve surface deposition increase the uniformity of thickness and enhance filling with high aspect ratio features and improve the overall plating [8][9][10][11]. Sulfuric acid is used as a highly conductive electrolyte and chloride ions improve the performance of additives.…”

Development of electro-copper plating with nanodiamonds for electronic interconnects in advanced packaging

“…Because an electro-Cu plating technology is mainly used to form TSV interconnects, 5,6) the electro-Cu plating is a particularly important technology in the TSV process and developments of the electro-Cu plating technology are being advanced. [7][8][9][10][11][12] It is well-known that the Cu crystallite diameter and the crystal grains increase by selfannealing at room temperature. 13,14) This transformation leads to the generation of stress in wire formed by Cu.…”