Microvia Filling by Cu Electroplating Over a Au Seed Layer Modified by a Disulfide

Dow, Wei‐Ping; Chiu, Yong-Da; Yen, Ming-Yao

doi:10.1149/1.3078407

Cited by 72 publications

(65 citation statements)

References 109 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…4,6,8,10,21,24,31 MPA and MPO are ineffective additives for copper superfilling; they inhibit copper electrodeposition. 31,38 TBPS is a new additive that is able to accelerate copper electrodeposition. 45,46 However, an effective plating formula for copper superfilling using TBPS as an accelerator has not yet been developed.…”

Section: Resultsmentioning

confidence: 99%

“…Thus far, thiol and sulfonic groups have been confirmed to be the necessary functional groups for accelerating copper deposition. 31,[38][39][40] Hence, SPS and MPS are effective additives for accelerating copper deposition in the presence of chloride ions.…”

mentioning

confidence: 99%

“…25,38,39,[45][46][47][48][49][50][51] If an organic additive can interact with chloride ions to accelerate copper nucleation and deposition, then the additive can adsorb onto a Cu or Au surface and can float on the copper deposit during electroplating. 31,38,39 The floatability of the organic additive determines its accelerating ability. 31,38,39 Cyclic voltammetry (CV) can be used to characterize the accelerating ability and the floatability of the accelerator using an Au electrode.…”

mentioning

confidence: 99%

“…31,38,39 The floatability of the organic additive determines its accelerating ability. 31,38,39 Cyclic voltammetry (CV) can be used to characterize the accelerating ability and the floatability of the accelerator using an Au electrode. 39,51 CV is performed in an electrolyte solution that contains copper ions, H 2 SO 4 , PEG, and chloride ions.…”

mentioning

confidence: 99%

See 3 more Smart Citations

Accelerator Screening by Cyclic Voltammetry for Microvia Filling by Copper Electroplating

Chiu

Dow

2013

J. Electrochem. Soc.

Self Cite

View full text Add to dashboard Cite

A cyclic voltammetry (CV) screening method is proposed in this work to identify an effective accelerator for the copper superfilling of microvias of a printed circuit board (PCB). Five typical organosulfides are used as model additives to evaluate the performance of the screening method. The five organosulfides are 3-mercapto-1-propanesulfonate (MPS), bis(3-sulfopropyl) disulfide (SPS), 3-mercaptopropionic acid (MPA), 3-mercapto-1-propanol (MPO), and 3,3-thiobis(1-propanesulfonate) (TBPS), where MPS, MPA, and MPO contain a thiol head-group, SPS contains a disulfide group, and TBPS contains a thioether group. MPS, SPS, and TBPS have one or two terminal groups of sulfonates, whereas MPA has a terminal group of carboxylic acid, and MPO has a terminal group of alcohol. The CV screening method revealed that MPS, SPS, and TBPS are accelerators for copper electrodeposition and that MPA and MPO are not. A specific copper deposition peak, specifically, the α peak, that appears in the CV patterns is an indicator for accelerator screening. This study is the first to indicate that TBPS with a thioether group rather than a thiol group can accelerate copper electrodeposition and can be used for the copper superfilling of the microvias of a PCB.

show abstract

Section: Resultsmentioning

confidence: 99%

mentioning

confidence: 99%

mentioning

confidence: 99%

mentioning

confidence: 99%

See 2 more Smart Citations

Accelerator Screening by Cyclic Voltammetry for Microvia Filling by Copper Electroplating

Chiu

Dow

2013

J. Electrochem. Soc.

Self Cite

View full text Add to dashboard Cite

show abstract

“…The surface smoothing capacity and stability 22,23 associated with the CEAC mechanism has been evaluated as has the influence of surface diffusion 24 and surface derivatization. 2,18,[24][25][26][27] Research on sulfite chemistry for Au electrodeposition reportedly dates back to 1842. 28 Compared to cyanide, sulfite electrolytes are environmental friendly but suffer from disproportionation, SO 2 formation, and/or dithionnite-based decomposition in acidic media.…”

mentioning

confidence: 99%

Superfilling Damascene Trenches with Gold in a Sulfite Electrolyte

Josell

Moffat

2013

J. Electrochem. Soc.

View full text Add to dashboard Cite

Superconformal Au deposition is demonstrated in a Na 3 Au(SO 3 ) 2 -Na 2 SO 3 based electrolyte using underpotential deposited (upd) Pb to catalyze the reduction of Au(SO 3 ) 2 3− . Micromolar additions of Pb 2+ to the electrolyte give rise to acceleration of the Au deposition rate as evidenced by hysteretic voltammetry and rising chronoamperometric transients that convolve the diffusion, adsorption kinetics and coverage isotherm of the upd Pb catalyst. The catalytic activity on the Au deposition reaction may be quenched, or reset, by stepping the potential to more positive values to deactivate or strip the Pb catalyst. Void-free Damascene trench superfilling at various fixed potentials and Pb 2+ concentrations is demonstrated and shown to be congruent with the curvature enhanced accelerator model (CEAC) of superconformal growth. This includes enhanced deposition due to catalyst enrichment on concave surface segments at the bottom corners of the trenches, followed by rapid bottom-up growth and, for certain conditions, bump formation above the filled trenches.Superconformal film growth by additive-based electrodeposition underlies the successful implementation of Cu in state-of-the-art multilevel interconnect metallization for the silicon based semiconductor industry. 1,2 In contrast, electrodeposited Au remains the metallization of choice for interconnects and contacts in compound semiconductors and related optoelectronics applications as detailed in recent reviews. 3,4 To date the majority of these applications have involved through-mask-electrodeposition. However, increasing circuit densification demands a move to three-dimensional metallization to enable the fabrication of interconnect networks of arbitrary design and complex architectures. 1 Implementation of the Damascene process calls for a Au electroplating chemistry that can provide void-free filling of recessed surface features. Previously two different Au electrolytes have been examined and shown to be capable of void-free feature filling. The first derives from the original observation of McIntryre and Peck that underpotential deposited (upd) Pb catalyzes Au deposition from KAu(CN) 2 -based electrolytes. 5 When this acceleration is combined with mass conservation of the surfactant in the presence of electrode area change, superconformal Au void-free feature filling occurs in accord with the CEAC model. 6,7 Practically speaking, two short-comings of the system are electrolyte toxicity and the aggressive nature of the alkaline media towards photoresist materials. 3,4 In order to address these challenges a sulfite-based Au electrolyte was evaluated by Hu and Ritzdorf. 8 The addition of mercaptopropane sulfonic acid (MPS) to a commercial electrolyte comprised of Na 3 Au(SO 3 ) 2 , Na 2 SO 3 , a pH buffer and Tl + as a "grain refiner" enabled void-free superconformal deposition. Electroanalytical measurements indicate that MPS serves as an inhibitor that facilitates feature filling in line with traditional leveling concepts 9 although no quantitative modeli...

show abstract

Superconformal Deposition

Josell¹,

Moffat²

2020

Surface and Interface Science

View full text Add to dashboard Cite

Microvia Filling by Cu Electroplating Over a Au Seed Layer Modified by a Disulfide

Cited by 72 publications

References 109 publications

Accelerator Screening by Cyclic Voltammetry for Microvia Filling by Copper Electroplating

Accelerator Screening by Cyclic Voltammetry for Microvia Filling by Copper Electroplating

Superfilling Damascene Trenches with Gold in a Sulfite Electrolyte

Superconformal Deposition

Contact Info

Product

Resources

About