Direct Cu Electrodeposition on Ta Using Pd Nanocolloids: Effect of Allyl Alcohol on the Formation of Seed Layer

Abstract

Cu direct electrodeposition (ED) on a Ta substrate was performed using Pd nanocolloids (NCs) as a Cu nucleation promoter. Pd NCs were synthesized by a polyol method and loaded onto a pretreated Ta substrate. Through a two-step potentiostatic ED process in a pyrophosphate-based electrolyte, a continuous Cu seed layer was deposited on the Ta substrate, although the surface showed irregular morphology. The addition of allyl alcohol improved the surface regularity of the Cu seed layer, allowing the conformal Cu seed layer to be formed successfully on the 55 nm patterned Ta substrate. Cu gap-filling was achieved by galvanostatic ED in a sulfate-based electrolyte on the preformed seed layer.

Accuracy Improvement in Cyclic Voltammetry Stripping Analysis of Thiourea Concentration in Copper Plating Baths

“…Organic additives are important constituents of the electroplating baths owing to their ability to control the morphology and the film properties of the plated material. [1][2][3][4][5][6][7][8][9][10][11][12][13][14][15][16][17] The organic additives are typically grouped into suppressors, accelerators, and levelers, based on their roles and functionality. [1][2][3][4][5][6][7][8][9][10][11][12][13][14][15][16][17] Examples of organic additives in electroplating baths include bis(3-sulfopropyl) disulfide, polyethylene glycol (PEG), janus green b (JGB), polyethylene imine (PEI), 1,2,3-benzotriazole (BTA), and thiourea (TU).…”

“…[1][2][3][4][5][6][7][8][9][10][11][12][13][14][15][16][17] The organic additives are typically grouped into suppressors, accelerators, and levelers, based on their roles and functionality. [1][2][3][4][5][6][7][8][9][10][11][12][13][14][15][16][17] Examples of organic additives in electroplating baths include bis(3-sulfopropyl) disulfide, polyethylene glycol (PEG), janus green b (JGB), polyethylene imine (PEI), 1,2,3-benzotriazole (BTA), and thiourea (TU). 1,2,[6][7][8][9][10][11][12][13][18][19][20][21][22][23]<...…”

“…[1][2][3][4][5][6][7][8][9][10][11][12][13][14][15][16][17] Examples of organic additives in electroplating baths include bis(3-sulfopropyl) disulfide, polyethylene glycol (PEG), janus green b (JGB), polyethylene imine (PEI), 1,2,3-benzotriazole (BTA), and thiourea (TU). 1,2,[6][7][8][9][10][11][12][13][18][19][20][21][22][23][24][25][26][27][28][29] TU is a common additive in Cu and Ag electrodeposition baths and induces leveling and grain refining properties. [18][19][20][21][22][23][24][25][26] TU has been used as an additive either solely or in combination with Cl − (TU-Cl − ) in baths used for electrodeposition processes involving various c...…”