In this study, we employed a simple galvanostatic method to evaluate the Cu filling performance in sub-micron trenches using a convection-dependent adsorption characteristic of levelers. Our technique simulates selective adsorption at the trench by different rotation speeds of RDE, and used their potential difference to predict the filling performance. SEM observation was used to conform what was predicted by RDE experiments. This method might be useful to evaluate other plating additives to detect the electroplating bath.
Two new levelers were studied and they exhibited considerable difference in filling performance. It is because their different amino groups were locating at different positions. Diffusion-adsorption mechanism and convection-dependent adsorption were used to explain their plating behaviors. Results from galvanostatic measurements on wafer fragments demonstrated that a synergistic inhibiting behavior between the PEG and leveler was operational in certain concentration ranges. Beyond this range, defects were formed. XRD and surface roughness analysis by AFM indicated a negligible variation with respect to leveler concentration.
References
[1]. R.H. Havemann and J. A. Hutchby, “High-performance interconnects: An .Integration Overview”, Proc. IEEE 2001, 89: 586-601.
[2]. D. Edelstein, J. Heidenreich, R. Goldblatt, W. Cote, C. Uzoh, N. Lustig, P. Roper, .. T. McDevitt, W. Motsiff, A. Simon, J. Dukovic, R. Wachnik, H. Rathore,
..R. Schultz, L. Su, S. Luce, and J. Slattery, “Full Copper Wiring in a Sub-0.25 μm CMOS ULSI Technology”, Technical Digest, IEEE International Electron
. .Devices .Meeting 1997, 773-76.
[3]..T.Y.B. Leung, M. Kang, B.F. Corry, and A.A. Gewirth, “Benzotriazole as an .Additive for Copper Electrodeposition: Influence of Triazole Ring
.Substitution”, .J..Electrochem. Soc. 2000, 147: 3326-37.
[4]. T.P. Moffat, J.E. Bonevich, W.H. Huber, A. Stanishevsky, D.R. Kelly, G.R.
.Stafford, and D. Josell, “ Superconformal Electrodeposition of Copper in 500-90 .nm Features”, J..Electrochem. Soc. 2000, 147: 4524-35.
[5]. J.J. Kim, S.K. Kim, and J.U. Bae, “Investigation of Copper Deposition in the .Prensence of Benzotriazole”, Thin Solid Films 2002, 415: 101-07.
[6]. W.P. Dow, and C.W. Liu, “Evaluating the Filling Performance of a Copper .Plating Formula Using a Simple Galvanostat Method”, J..Electrochem. Soc.
. 2006, 153: C190-94.
[7]. P.C. Andricacos, C. Uzoh, J.O. Dukovic, J. Horkans, and H. Deligianni, .“Damascene Copper Electroplating for Chip Interconnections”, IBM J. Res.
.Electrorefining Electrolytes”, Hydrometallurgy 2000; 56: 255-68.
[9]. J. Reid, ”Copper Electrodeposition: Principles and Recent Progress”, Jpn.
J. Appl. Phys. 2001; 40: 2650-57.
[10]. M. Georgiadou, D. Veyret, R.L. Sani, and R.C. Alkire, “Simulation of Shape .Evolution during Electrodeposition of Copper in the Presence of Additive”, J.
.Electrochem. Soc. 2001, 148: C54-58.
[11]. A.C. West, “Theory of Filling of High-Aspect Ratio Trenches and Vias in Presence of Additives”, J..Electrochem. Soc. 2000, 147: 227-32.
[12]. S.C. Chang, J.M. Shieh, K.C. Lin, B.T. Dai, T.C. Wang, C.F. Chen, M.S. Feng, .Y.H. Li, and C.P. Lu, “Investigation of Effects of Bias Polarization and
.Chemical Parameters on Morphology and Filling Capability of 130 nm
.Damascene Electroplated Copper”, J. Vac. Sci. Technol. B 2001, 19: 767-73.
[13]. S.C. Chang, J.M. Shieh, B.T. Dai, M.S. Feng, and Y.H. Li, “The Effects of .Plating Current Densities on Self-Annealing Behaviors of Electroplated Copper .Films”, J. .Electrochem. Soc. 2002, 149: G535-38.
[14]. J.J Kelly, C. Tian, and A.C. West, “Leveling and Microstructural Effects of Additives for Copper Electrodeposition”, J..Electrochem. Soc. 1999, 146:
2540-45.
[15]. W.P. Dow, H.S. Huang, and Z. Lin, “Interactions between Brightener and Chloride Ions on Copper Electroplating for Laser-Drilled Via-Hole Filling”, .Solid -State Lett.. 2003, 6: C134-36
[16]. W.P. Dow and H.S. Huang, “Role of Chloride Ion in Microvia Filling by Copper .Electrodeposition: Ⅰ. Studies Using SEM and Optical Microscope”,
.J..Electrochem. Soc. 2005, 152: C67-76.
[17]. W.P. Dow, H.S. Huang, M.Y. Yen, and H.H. Chen, “Role of Chloride Ion in
Galvanostatic Measurements”, J..Electrochem. Soc. 2005, 152: C77-88.
[18]. J.J. Kelly and A.C. West, “Copper Deposition in the Presence of Polyethylene Glycol: Ⅰ. Quartz Crystal Microbalance Study”,.J..Electrochem. Soc. 1998, 145:
3472-76.
[19]. J.J. Kelly and A.C. West, “Copper Deposition in the Presence of Polyethylene Glycol: Ⅱ. Electrochemical Impedance Spectroscopy”,.J..Electrochem. Soc.
1998, 145: 3477-81.
[20]. K.R. Hebert, “Rule of Chloride Ions in Suppression of Copper Electrodeposition .By Polyethylene Glycol”, J..Electrochem. Soc. 2005, 152: C283-87.
[21]. W.H. Li, J.H. Ye, and S.F.Y. Li, “Electrochemical Deposition of Copper on ,Patterned Cu/Ta(N)/SiO2 Surfaces for Superfilling of Sub-micron Features”, J.
.Appl. Electrochem. 2001, 31: 1395-97.
[22]. S.C. Chang, J.M. Shieh, K.C. Lin, B.T. Dai, T.C. Wang, C.F. Chen, M.S. Feng, Y.H. Li, and C.P. Lu, “Wetting Effect on Gap Filling Submicron Damascene by a Electrolyte Free of Levelers”, J. Vac. Sci. Technol. B 2002, 20: 1311-16.
[23]. M Hayase, M. Taketani, K. Aizawa, T. Hatsuzawa, and K. Hayabusa,
“Copper Bottom-up Deposition by Breakdown of PEG-Cl Inhibition”, .Solid -State Lett.. 2002, 5: C98-101.
[24]. W.P. Dow, M.Y. Yen, W.B Lin, and S.W. Ho, “Influence of Molecular Weight of .Polyethylene Glycol on Microvia Filling by Copper Electroplating”, J.
.Electrochem. Soc. 2005, 152: C769-775.
[25]. M. Yokoi, S. Konishi, and T. Hayashi, “Adsorption Behavior of
Electrodeposition”, Solid-State Lett.. 2005, 8: C6-8.
[27]. S.K. Kim and J.J. Kim, “Superfilling Evolution in Cu Electrodeposition- .Dependence on the Aging Time of the Accelerator”, Solid -State Lett.. 2004, 7:
.C98-100.
[28]. S.K. Cho, S.K. Kim, and J.J. Kim, “Superconformal Cu Electrodeposition Using .DPS”, J..Electrochem. Soc. 2005, 152: C330-33.
[29]. A.C .West, S. Mayer, and J. Reid, “A Superfilling Model that Predicts Bump .Formation”, Solid -State Lett.. 2001, 4: .C50-53.
[30]. S.K. Kim, S.K. Cho, J.J. Kim, and Y.S. Lee, “ Superconformal Cu
.Eletrodeposition on Various Substrates”, Solid -State Lett.. 2005, 8: .C19-21.
[31]. T.P. Moffat, D. Wheeler, W.H. Huber, and D. Josell, “ Superconformal . .Electrodeposition of Copper”, J..Electrochem. Solid -State Lett.. 2001, .4: .C26-29.
[32]. D. Josell, D. Wheeler, W.H. Huber, and T.P. Moffat, “Superconformal . . Electrodeposition in Submicron Features”, Phys. Rev. Lett. 2001, 87:
.016102-(1-4).
[33]. D. Josell, D. Wheeler, W.H. Huber, J.E. Bonevich, and T.P. Moffat, “A Simple .Equation for Predicting Superconformal Electrodeposition in Submicrometer .Trenches”, J..Electrochem. Soc. 2001, 148: C767-73.
[34]. D. Josell, D. Wheeler, and T.P. Moffat, “Superconformal Electrodeposition in .Vias”, Solid -State Lett.. 2002, 5: .C49-52.
[35]. D. Josell, B.Baker, C.Witt, D. Wheeler, and T.P. Moffat, “Via Filling by
.Electrodeposition: Superconformal Silver and Copper and Conformal Nickel”, .J..Electrochem. Soc. 2002, 149: C637-41.
[36]. T.P. Moffat, D. Wheeler, S.K. Kim, and D. Josell, “Curvature Enhanced
Electrochim. Acta 2007, 53: 145-54.
[37]. K.C. Lin, J.M. Shieh, S.C. Chang, B.T. Dai, T.C. Wang, C.F. Chen, and M.S.
.Feng, “Electroplating Copper in Sub-100 nm Gaps by Additives with Low .Consumption and Diffusion Ability”, J. Vac. Sci. Technol. B 2002, 20: 940-45.
[38]. W.P. Dow, H.S. Huang, M.Y. Yen, and H.C. Huang, “Influence of
.Convection-Dependent Adsorption of Additives on Microvia Filling by Copper .Electroplating”, J..Electrochem. Soc. 2005, 152: C425-34.
[39]. S.K. Kim, D. Josell, and T.P. Moffat, “Electrodeposition of Cu in the .PEI-PEG-Cl-SPS Additive System: Reduction of Overfill Bump Formation . .During Superfilling”, J..Electrochem. Soc. 2006, 153: C616-22.
[40]. B. Bozzini, L. D’Urzo, and C. Mele, “A Novel Leveller for the Electrodeposition of Copper from Acidic Sulphate Bath: A Spectroelectrochemical Investigation”, Electrochim. Acta 2007, 52: 4767-4777.
[41]. S.Y. Chiu, J.M. Shieh, S.C. Chang, K.C. Lin, B.T. Dai, C.F. Chen, and M.S.
Feng, “Characterization of Additive Systems for Damascene Cu Electroplating by the Superfilling Profile monitor”, J. Vac. Sci. Technol. B 2000, 18: 2835-41.
[42]. J.J Kelly, and A.C. West, “Leveling of 200 nm Features by Organic Additives”, Solid -State Lett.. 1999,22: .561-63.
[43]. J.J. Sun, K. Kondo, T. Okamura, S.J. Oh, M. Tomisaka, H. Yonemura, M.
Hoshino, and K. Takahashi., “High-Aspect-Ratio Copper Via Filling Used for Three-Dimentional Chip Stacking”, J. Electrochem. Soc. 2003, 150: G335-58.
[44]. S. Miura and H. Honma, “Advanced Copper Electroplating for Application of
.Overfill Bumps in Cu Superfilling”, J..Electrochem. Soc. 2006, 153: C826-33.
[47]. D. Roha and U. Landau, “Mass Transport of Leveling Agents in Plating:
Steady-State Model for Blocking Additives”, J..Electrochem. Soc. 1990, 137:
824-34.
[48]. K.G. Jordan and C.W. Tobias, “The Effect of Inhibitor Transport on Leveling in Electrodeposition”, J..Electrochem. Soc. 1991, 138: 1251-59.
[49]. C.C. Cheng and A.C.West, “Flow Modulation as a Means of Studying Leveling Agents”, J..Electrochem. Soc. 1998, 145: 560-64.
[50].Y. Cao, P. Taephaisitphongse, R. Chalupa, and A.C. West, “Three-Additive Model of Superfilling of Copper”, J..Electrochem. Soc. 2001, 148: C466-72.
[51]. J Reid, C. Gack and S.J. Hearne, “Cathodic Depolarization Effect during Cu Electroplating on Patterned Wafers”, Solid -State Lett.. 2003,26: .C26-29.