Direct Copper Plating on Ultra-Thin Sputtered Cobalt Film in an Alkaline Bath

Xu, Wen-Zhong; Xu, Junhua; Lu, Hai-Sheng; Wang, Jing-Xuan; Hu, Z. Q.; Qu, Xin-Ping

doi:10.1149/2.013312jes

Cited by 39 publications

(28 citation statements)

References 34 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…The mechanistic analysis of the first deposition stages using chronoamperometric data has usually been performed by recording the response after the application of a typical single potentiostatic step. This procedure, however, does not lead to reliable results when stabilization of the intermediate occurs, so that comments related to divergent or unexpected results have been included in some of the reports [4,[15][16][17].…”

Section: Introductionmentioning

confidence: 99%

Advances in Copper Electrodeposition in Chloride Excess. A Theoretical and Experimental Approach

Sebastián

Torralba

Vallés

et al. 2015

Electrochimica Acta

View full text Add to dashboard Cite

A B S T R A C TThis is an in depth study in the knowledge of the nucleation and growth mechanism that governs copper electrodeposition in excess chloride media. In these conditions copper electro-reduction takes place via two well-separated steps, since the Cu(I) intermediate is stabilized through chloride complexation. The process was studied in two media, a deep eutectic solvent (DES) based on a mixture of urea and choline chloride, and in excess chloride aqueous solution, in order to also analyse solvent influence on the early stages of the deposition process. In both media, copper electrodeposition follows a nucleation and a diffusion controlled three-dimensional growth mechanism. In line with a previous work a double potentiostatic step signal was employed to record j-t transients associated to both nucleation and growth stages, and from them, the whole mechanistic analysis of the copper electrodeposition was performed. This analysis involved the calculation of the surface concentrations of Cu(II), free Cu(I) and complexed Cu (I) for any time and potential required and the application of Sharifker-Hills model, j m 2 t m products and rising part analysis including the calculated parameters, which are strengthened as valuable tools for complete copper electrodeposition analysis in these media.

show abstract

Section: Introductionmentioning

confidence: 99%

Advances in Copper Electrodeposition in Chloride Excess. A Theoretical and Experimental Approach

Sebastián

Torralba

Vallés

et al. 2015

Electrochimica Acta

View full text Add to dashboard Cite

show abstract

“…This fact supports that the longer OCP time enables greater replacement between the Cu 2+ and UPD-Mn and tends to yield a Cu(Mn) film with a higher Cu concentration. The Cu(111) orientation can extend the use of Cu(Mn) in the Cu interconnects because the (111) orientation has a low strain energy and surface energy [29,30]. However, a peak corresponding to the Cu 2 O (111) (2θ = 36.7 • ) and (200) (2θ = 42.5 • ) (JCPDS 78-2076) was also found in the XRD pattern because Cu 2+ might react with the residual oxygen in the electrolyte, because oxygen is inevitable although the deionized water has been previously degassed by bubbling high-purity nitrogen.…”

Section: Ocp (S)mentioning

confidence: 99%

A New Alternative Electrochemical Process for a Pre-Deposited UPD-Mn Mediated the Growth of Cu(Mn) Film by Controlling the Time during the Cu-SLRR

et al. 2020

View full text Add to dashboard Cite

A layer-by-layer deposition is essential for fabricating the Cu interconnects in a nanoscale-sized microelectronics because the gap-filling capability limits the film deposition step coverage on trenches/vias. Conventional layer-by-layer electrochemical deposition of Cu typically works by using two electrolytes, i.e., a sacrificial Pb electrolyte and a Cu electrolyte. However, the use of a Pb electrolyte is known to cause environmental issues. This study presents an Mn monolayer, which mediated the electrochemical growth of Cu(Mn) film through a sequence of alternating an underpotential deposition (UPD) of Mn, replacing the conventionally used UPD-Pb, with a surface-limited redox replacement (SLRR) of Cu. The use of the sacrificial Mn monolayer uniquely provides redox replacement by Cu2+ owing to the standard reductive potential differences. Repeating the sequence of the UPD-Mn followed by the SLRR-Cu enables Cu(Mn) film growth in an atomic layer growth manner. Further, controlling the time of open circuit potential (OCP) during the Cu-SLRR yields a technique to control the content of the resultant Cu(Mn) film. A longer OCP time caused more replacement of the UPD-Mn by the Cu2+, thus resulting in a Cu(Mn) film with a higher Cu concentration. The proposed layer-by-layer growth method offers a wet, chemistry-based deposition capable of fabricating Cu interconnects without the use of the barrier layer and can be of interest in microelectronics.

show abstract

“…Co have been considered as adhesion materials for direct Cu plating [1,[3][4][5]. Ru (5 nm)/TaN (5 nm) was only stable up to 450⁰C though the failure was due the formation of TaSi 2 [6], and Co (10 nm)/TaN (10 nm) can also stand 600⁰C annealing for 30 min [7].…”

Section: Introductionmentioning

confidence: 99%

“…Ethylenediamine (En) can chelate and effectively stabilize both cupric and cuprous ions in aqueous solutions, so it can be used as an additive for non-cyanide alkaline electroplating of Cu [18]. CuSO 4 -En bath has been used for direct plating of Cu onto Co in the alkaline investigated by S. Armini and our group [3,4].…”

Section: Introductionmentioning

confidence: 99%

Study of direct Cu electrodeposition on ultra-thin Mo for copper interconnect

Xu¹,

Cao²,

Yang³

et al. 2016

Microelectronic Engineering

Self Cite

View full text Add to dashboard Cite

Direct electrodeposition (ECD) process of copper film on ultra-thin molybdenum film is investigated in both copper sulfate-sulfuric acid (CuSO 4-H 2 SO 4) acidic bath and copper sulfate-ethylenediamine (CuSO 4-En) neutral bath (pH = 7.5). The neutral electrolyte containing 0.03 M CuSO 4 and 0.06 M En was chosen to avoid excessive corrosion of Mo and introduction of other ions. The complexing effect of En affects the electrodeposition process of Cu on Mo. Potentiodynamic polarization curves and scanning electron microscopic characterization show that Cu can be electroplated in CuSO 4-En bath with lower corrosion rate, greater nucleation density and shorter fully-covering time than that in CuSO 4-H 2 SO 4 bath. The fitting results of current-time transients using Scharifker and Hill's model support the instantaneous nucleation and growth of Cu on Mo in both CuSO 4-H 2 SO 4 bath and CuSO 4-En bath (with background electrolyte) at the initial stage of electrodeposition. By using an optimized two-step plating process (at the current density of 8 mA/cm 2 in the first step for a short time and 4 mA/cm 2 in the second step), the resistivity of direct ECD Cu on Mo was almost the same to that of ECD Cu on Cu/Mo in the same plating bath.

show abstract

Direct Copper Plating on Ultra-Thin Sputtered Cobalt Film in an Alkaline Bath

Cited by 39 publications

References 34 publications

Advances in Copper Electrodeposition in Chloride Excess. A Theoretical and Experimental Approach

Advances in Copper Electrodeposition in Chloride Excess. A Theoretical and Experimental Approach

A New Alternative Electrochemical Process for a Pre-Deposited UPD-Mn Mediated the Growth of Cu(Mn) Film by Controlling the Time during the Cu-SLRR

Study of direct Cu electrodeposition on ultra-thin Mo for copper interconnect

Contact Info

Product

Resources

About