TSV Fillings and Electrochemical Measurements of the Dialyl-amine Additive with Cl⁻and Br⁻

Abstract

The TSV filling using the dialyl-amine and the Br − and Cl − halogen ions to a copper electrodeposition bath is reported. The TSV bottom acceleration and TSV outside inhibition have been measured by an electrochemical method using the rotating disk electrode and numerical computation of the fluid dynamics. A perfect TSV filling is achieved with 1 ppm P(DAMA[HBr]/SO 2 ) + 1 ppm of Br − and the electrodeposited morphology is fine and bright. This shows acceleration at the lower rotation speeds of the rotating disk electrode and an inhibition at the higher speeds, if compared to 1 ppm P(DAMA[HCl]/SO 2 ) + Cl − 1 ppm. Br − 1 ppm shows a stronger inhibition at the higher rotation speeds, if compared to Cl − 1 ppm. The addition of SPS in addition to Br − 1 ppm shows acceleration at the lower speeds. No voids formed at the higher current density of 3.5 mA/cm 2 with SPS. © The Author Filled via stacking is an inevitable element of the buildup printed circuit boards in order to achieve high density interconnections. 1,2The vias are filled by the copper electrodeposition. Not only the builtup printed circuit boards, but also silicon chips are stacked with the through silicon via (TSV).3-5 For both the filled via and TSV, the vias are filled by the copper electrodeposition.2 Electrodeposition inhibition at the via outside and acceleration at the via bottom require desired current distributions to fill the vias without voids. The additives of an inhibitor, accelerator, leveler and halogen ion are necessary. 6,7 The halogen ion, in most cases Cl − , interaction with the inhibitor and accelerator is extremely important for the additive role. 8 The Cl − adsorbs at the copper electrodeposit and forms a cuprous electron bridge and binds with the polyethylene glycol (PEG). This Cl − , cuprous and PEG complex inhibit the copper electrodeposition.9,10 Completely different cyclic voltammetries (CV) have been reported for thiourea with and without Cl − by MS Kang. We focused on the dialyl-amine. M. Takeuchi reported that the Cl − counter ions adsorb on copper and inhibit the via outside electrodeposition. 21,22 However, no study currently exists on the effect of halogen ions with the dialyl-amine. In this report, the TSV fillings and electrochemical measurements have been compared with two halogen ions of Cl − and also Br − . ExperimentalThe basic bath consists of 130 × 10 3 ppm of CuSO 4 · 5H 2 O and 200 × 10 3 ppm of H 2 SO 4 . Figure 1 shows the structure of the dialyl- * Electrochemical Society Active Member. z E-mail: kkondo@chemeng.osakafu-u.ac.jp amines. (a) the P(DAMA[HBr]/SO 2 ) counter ion is Br − , and (b) the P(DAMA[HCl]/SO 2 ) counter ion is Cl − . The dialyl-amine concentration is 1 ppm and 1 and 50 ppm of the halogen are added.The TSV via has a diameter of 5 μm and depth of 40 μm. The stirring speed of the magnetic stirrer is 1000 rpm, the current density is 3 mA/cm 2 and the electrodeposition time is 60 min. The TSV substrates are imbedded in the resin and polished then observed by FE-SEM (Hitach, S-4300).COMSOL Multi...

Communication—Halide Ions in TEG-Based Levelers Affecting TSV Filling Performance

“…To replicate this, the rotating speed of Cu RDE was changed from 1000 to 0 rpm. 2,[4][5][6][7] LSVs without PEG-PPG and SPS are depicted in Fig. S1, demonstrating that the levelers induced convection dependent suppression with a magnitude in the order of Leveler-Cl < Leveler-Br < Leveler-I.…”

Structural Influence of Terminal Functional Groups on TEG-Based Leveler in Microvia Filling

“…2,19,21,22 Recent studies report that the inhibition effect of levelers can be varied by the structure of levelers, such as functional groups, 19,[23][24][25] side chain length, [26][27][28] aromatic rings, 29,30 and counter ions. [31][32][33] Thus, studying the better understanding of the structure-property relationship of additives could assist in understanding the inhibition mechanism of levelers for achieving void-free filling and designing the new levelers.…”

Microvia Filling with Copper Electroplated with Quaternary Ammonium-Based Leveler: The Evaluation of Convection-Dependent Adsorption Behavior of the Leveler

“…Typically, the electrolyte in the vicinity of the bottom of the microvia is quiescent compared to that at the top, and thus CDA behavior enhances the deposition rate at the bottom. 22,23 The CDA behavior of various levelers and its interaction with halide ions 24,25 and other additives 6,26 have been studied. Usually, the potential difference between 100 rpm and 1000 rpm for galvanostatic Cu electrodeposition can be considered an indicator of filling performance.…”