ELECTROLESS PLATING Cu ON Mo POWDER AND ITS REACTION MECHANISM

45 «4 Vol.45 No.4 2009 4 405 409 ACTA METALLURGICA SINICA Apr. 2009 pp.405 409 Mo ³ß Cu Đ Æ 1) ÊÉ Þº²¾ º Ò¾ µ, 410083 2) ÊÉ ²¾ º, 410083» ³³ Sn Pd Å Mo Ô Cu ÎƼ Cu/Mo, ³³ XRD, SEM, EDS XPS Ú ÎÞ ¼. ³³ XPS ¼ Mo Ô Cu ¾ ÁÕ. Ú³¼ Ô Cu ¾ È Pd µ Þ Î Ú Cu Ê Å Ð³. Ý Ô Cu, Mo, Cu/Mo, È ¾ Å TQ153.1 ²Ö A ¼ÕÅ 0412 1961(2009)04 0405 05 ELECTROLESS PLATING Cu ON Mo POWDER AND ITS REACTION MECHANISM WANG Guangjun, WANG Dezhi, ZHOU Jie, WU Zhuangzhi, XU Bing 1) Key Laboratory of Nonferrous Metal Materials Science and Engineering, Ministry of Education, Central South University, Changsha 410083 2) School of Materials Science and Engineering, Central South University, Changsha 410083 Correspondent: WANG Dezhi, professor, Tel: (0731)8877221, E-mail: dzwang@mail.csu.edu.cn Manuscript received 2008 04 17, in revised form 2008 12 10 ABSTRACT By using Sn Pd catalyst system, the electroless plating Cu on the surface of Mo powder was performed to fabricate Cu/Mo composite powder. Composition, morphology and formation process of Cu/Mo particles were analyzed by XRD, SEM/EDS and XPS. The formation mechanism of Cu/Mo particles can be described as follows: the PdCl 2 (activator) deposited on the surface of Mo particles firstly and then was reduced by SnCl 2 (sensitizer) to nano Pd particles, which are the nucleation sites for Cu deposition, finally Cu coating formed. KEY WORDS electroless plating Cu, Mo powder, Cu/Mo composite powder, reaction mechanism Cu/Mo ³ Å Þ,», ¹ Á ¹ É, Ñ Å ½» [1]. Cu/Mo ³ Ã Ï ²Ð Å Ñ Ù. Ð Ù, Ñ Cu Ð Mo ² Ñ, Cu ³. Ñ Ù Cu Ñ, Ä Ú. Î ½Ä Ö Cu/Mo ³, Ì» à ٠ÉØ» [2,3]. ϲ, Ã Û Mo/Cu ³ Þ ±Ò [4] ; ÝÉ Ø Ð, ÝÓ ¾, ³ [5]. Û «¼, ϲ Ó, ±, ÝÓÏ ¾ Ú. Mo º Cu, Ý ÑÅÐ Ù * : 2008 04 17, Đ : 2008 12 10 Ð Ü : ˹, Ì, 1982, ± Ï Cu/Mo ³ Mo ÉÔÔ, Ñ, ËÑÄË, Ù Cu/Mo ³. À¾,» À Õ Õ Á Õ ( Ãß Æ ) [6] Ä. ϲ ¹ Mo Å, ± Í Mo ĐÐ Õ. ÂÈ, Õ Á Õ Ö Ó, ½ Ð ¼. Õ» ÁÅ Ç Ä ½ [7,8], Ï Ñ ÀÖ, ÏÏ µ Mo «Õ Cu. Õ Cu Mo Õ Cu, XPS Û Đ É± ĐÐ. 1 µ Ð 1.1 ºÜ Mo ¼ Cu ß, º Ð

406 Ý ¹ Å 45 «Ñ Ì, Õ ÈÐÛ ĐÐ ±, Í Õ. µ Ç Á Õ Cu ± [7,8], Đ Û ½ ± : (1) Ä. HF ĐÐÄ ±, Mo ß Ö Mo Æ Ä. (2) À. 10 g/l SnCl 2 + 40 ml/l HCl À ĐÐÀ ±. (3) Ã. 0.5g/L PdCl 2 +40 ml/l HCl à ĐÐà ±. «¼ ĐÐ Ñ, Ó Ò Ö Ô. 1.2 Cu «¼ ± Mo ² Õ Cu, à ± Æ Ï Õ, ph Ê Ì 12.5 13,  Mo, Ö 55 ĐÐĐ. Õ Cu Æ Ö Ô ÀÔ 100 30 min. Õ CuSO 4 Î, (HCHO) Î. Đ, (TEA) Þ (EDTA), Å Ã Ñ Ö Đ. Î 2, 2 ÒÓ (2, 2 bipridyl) Þ (PEG). µ Õ ( ) Î: 15 g/l CuSO 4 5H 2 O, 22 ml/l HCHO(37%,» ¾), 20 mg/l 2, 2 bipridyl, 30 g/l TEA, 3 g/l EDTA, 1 g/l PEG. 1.3 ÞÙ½ ± D/max2500 X Æ «Æ (XRD) Û ÆĐÐ Ñ, CuK α ÆÆ, Ç, Î 4 /min, 2θ ÍÎ 10 80 ; Sarion200 Ý (SEM) ÛĐ Ð Æ ß Đл; Tecnai G2 ÄÆ Ì (TEM)» ± Mo ß ; ESCALAB250 Ü Ã, X Æ º (XPS) ¹ Mo Õ Cu ÖØ, X Æ AlK α,» 1486.6 ev, 150 W. 2 µ ¹ 2.1 Cu/Mo «Þ XRD ± Æ 1 ÎÕ Cu Cu/Mo XRD. Î Mo Cu. Scherer Cu È Î 25 nm. µ XPS, 2θ=36 Î Cu 2 O «Æ. 2.2 Cu/Mo «XPS ± ν Õ, Û ĐÐ Æ Ö. Æ 2 Î Ar + Ð Mo XPS. Æ 3 Î XPS ¹» Æ Mo ¾¼ µ. ÃÆ, Å, O ¾, Cu ¾, À Á Cu 2 O Mo Cu Cu 2 O 10 20 30 40 50 60 70 80 2, deg 1 Cu/Mo Å XRD Fig.1 XRD pattern of Cu/Mo composite powder a b Cu 2p 1 C 1s 1000 800 600 400 200 0 Energy, ev 2 Cu/Mo Å XPS Fig.2 XPS of Cu/Mo composite powders before (a) and Atomic fraction of element, % after (b) Ar + etching for 100 s 100 80 60 40 20 Cu 2p Mo 3d 0 0 20 40 60 80 100 Etch time, s 3 Cu/Mo ½» Fig.3 Relationships of elements concentration and etch time measured by XPS Æ, Ý Æα Cu 2 O»,  Ç, Cu 2 O ² Mo Cu ÕºÆ Ý ½. ϲ, É ¹ 60 ĐÐ, Cu ² Æ Cu 2 O [9]. Ý Û ½ Cu 2 O, À Ô¼É È Cu Å Ã µ. 2.3 Cu/Mo «SEM/EDS ± Æ 4a b ½ Mo ¼ Õ Cu

4 Ê : Mo Ó Cu Í Ð Ç 407 5 Cu/Mo Å EDS Fig.5 EDS of Cu/Mo composite powder c Cu 2p 1 b a C 1s Mo 3p 3 Mo 3d5 Sn 3d Mo 3p 1 Pd 3d 1000 800 600 400 200 0 6 Mo Ô Cu ÁÕ XPS Ø Fig.6 XPS for sensitized (a), activated (b) and Cu coated (c) Mo powders 4 Å SEM Ó Fig.4 SEM micrographs of powders (a) original Mo powder (b) Cu/Mo composite powder (c) high magnified image of Fig. 4b Cu/Mo ß. Æ, º Á ¼. Æ ÓÎÄ. ÃÆ 4c Mo ½Ë»Õ, È Î 100 nm. EDS (Æ 5) Á ² Cu, ¼ XPS Ù½ÑÂ. 2.4 Cu ÛÞ XPS ± Æ 6 Î Mo Õ Cu ÂÖØ XPS Ù. ÃÆ 6 a, À Mo ß Sn Mo. ÃÆ 6 b, À ± Mo PdCl 2, Mo ½ Pd, ÂÈ, Mo Sn. Õ Cu Mo, ¹ Cu º ÖÎ Ì, Ý XPS ÖÐÎ É,  ϻ Mo Û (Æ 6 c), O ² ¹ Æ. 1 Î Mo Õ Cu ÖØ Ù Ê. Æ 7 Î ÂÖØ Sn 3d 5/2 Ù 475 500 ev È XPS. ÃÆ 7a, Mo À Sn 3d 5/2 Ù ÊÎ 486.9 ev, 1 Cl 2p 3/2 Ù ÊÎ 198.7 ev, Àº Ù Ê ¼À SnCl 2 Sn 3d 5/2 Cl 2p 3/2 Ù ÊÑ, À ÁÀ SnCl 2 Mo. À Mo PdCl 2 Ã, Sn 3d 5/2 Cl 2p 3/2 Ù Ê 487.1 ev ( Æ 7b) 199.45 ev( 1). À Á Mo Ã, Sn 2+ Pd 2+ Æ Sn 4+, Ý Sn 4+ SnCl 4 ß Mo, Đ Î: Sn 2+ + Pd 2+ Sn 4+ + Pd (1) Æ 8 Îà Pd 3d 5/2 Ù 329 347 ev È

408 Ý ¹ Å 45 «Ø 1 Ð Î Mo Ô Cu Õ Sn, Pd, Cl Cu XPS Ø Ï Table 1 Binding energies of some compounds and XPS measured binding energies of Sn, Pd, Cl and Cu during plating Cu on Mo powder Compound and powder Pd 3d 5/2 Sn 3d 5/2 Cl 2p 3/2 Cu 2p 3/2 PdCl 2 335.0 (Pd) 198.4 (PdCl 2 ) 337.2 (PdCl 2 ) 198.4 (PdCl 2 ) SnCl 2 487.0 (SnCl 2 ) 198.7 (SnCl 2 ) CuSO 4 936.3 (CuSO 4 ) Sensitized Mo powder 486.9 (SnCl 2 ) 198.4 (SnCl 2 ) Activated Mo powder 335.5 (Pd) 487.1 (SnCl 4 ) 199.45 (SnCl 4 ) 336.86 (PdO) Cu coated Mo powder 932.62 (Cu) (ev) 934.65 (Cu 2 O) 935.69 (CuO) (a) Sn 3d 5/2 486.9 ev (b) Sn 3d 5/2 487.1 ev Sn 3d 3/2 Sn 3d 3/2 500 495 490 485 480 500 495 490 485 480 7 ÁÕ Mo XPS Sn 3d 5/2 «Fig.7 High resolution spectra of Sn 3d 5/2 peak in XPS of sensitized (a) and activated (b) Mo powders Pd 3d 3/2 Pd 3d 5/2 335.5 ev I (Pd) II (PdO) 348 346 344 342 340 338 336 334 332 330 328 8 Mo  XPS Pd 3d 5/2 «Ú Fig.8 Decomposition of Pd 3d 5/2 peak in XPS of activated Mo powder XPS. ÃÆ Pd 3d 5/2 Ù Ê 335.5 ev, ¼ÈÛ ÎÎ Pd, À Á Mo PdCl 2 Ã, ˽ΠPd. ÃÝ ÆÁ½Ã Sn 2+ Pd 2+ Æ Sn 4+. Æ 8 ÇÎ Pd Ù Î 335.5 ev, ÑÛ Pd Ù (335.1 ev [10] ) ½ 0.4 ev. Meenan [11] BaTiO 3 ÁÆ «Õ Cu» Pd 3d 5/2 Ù +0.4 ev, ßβ ¹ß Pd Sn. ϲÃÆ 7b À Mo ËÀ Sn, ½ß Pd Sn,  Pd 3d 5/2 Ù Å Pd Sn ß Û. ßÎ Pd 3d 5/2 Ù +0.4 ev ² ¹ Pd ÈÖ. XPS Õ È Pd Í Pd κ Ù. À² Î Ã Ì, Å» e 2 /(2R), R λ, e λ. »¼ Ì Û º ÑÂ, Fermi Ï ½ e 2 /(2R), Ýκ٠ÕÝ [12]. ÛÉ Ï, κ٠E = e 2 /(2R), Â Ç Ñ R = e 2 /(2 E)., Pd κ»Î 0.4 ev,  Pd Î 1.8 nm. Mo PdCl 2 Ã, Ë Î 1.8 nm Pd

4 Ê : Mo Ó Cu Í Ð Ç 409, ÝÀ Pd Î Õ Cu Æ Ã Ú. Æ 8 PdO II, Ù Î 336.86 ev, À² ÎÉ Ï Pd Ã, Ô ± Æ PdO. XPS Ù (Æ 6), Õ Cu, Mo ß Pd ¼ Sn. Æ 9 Î Cu/Mo Cu 2p Ù 925 965 ev XPS. ÃÆ Û, I Ù Î 932.62 ev, Û Î Cu, II Ù Î 934.65 ev, Û Cu 2 O, III Ù Î 935.69 ev, Û CuO. À Á Mo Õ Cu. XPS, Cu 2 O CuO Ù ¼ Ê ÓÒ, Â Ô ÍĐ. 2.5 Mo Ù Cu Þ «¼ Mo Õ Cu ÖØ XPS, Mo Õ Cu Рɱ, Æ 10. Mo À, Mo Ë SnCl 2 (Æ 10a). À Mo Ã, ¹ PdCl 2 SnCl 2 Cu 2p 1/2 Cu 2p 3/2 960 950 940 930 I (Cu) II (Cu 2 O) III (CuO) 9 Mo Ô Cu XPS Cu 2p «Ú Fig.9 Decomposition of Cu 2p peak in XPS of Cu coated Mo powders 10 Mo µ Ô Cu È Å Fig.10 Schematic of the reaction mechanism for electroless plating Cu on Mo particle (a) sensitization (c) electroless plating Cu (b) activation (d) oxidation, Mo Ë ÈÎ 3 4 nm Pd. Ý SnCl 4 ÑÎĐ ½ Mo. Î½Ö Đ ½, à Mo Ö Ô, ϲ SnCl 4 ÉÙ Ô, Ì ± Pd Æ PdO(Æ 10b). ± Mo Õ, Cu 2+ HCHO Cu Ó Ë Pd ÎÆ Ã Ú Mo. Ë Cu Å Æ Ã, Cu Ù Mo Ë. Cu Ù Ë, Ä Mo, ß Cu º (Æ 10c). ¹ Æ Cu Õ, Đ Ã Ò, Đ Æ. Â, º Cu Æ Ä (Æ 10d). 3 (1) Sn Pd Æ, Mo Õ Cu, Cu/Mo Ä, Cu 2 O, Cu 2 O Ç ²É Cu Æ Ù½. (2) XPS Û Õ Cu ÖØ, ½ Mo Õ Cu Рɱ. (3) Õ Cu Ì Pd È Pd Ù Å, ± Ë Mo Pd È Î 3 4 nm, À Pd ÑÎ Õ Cu Æ Õ Cu ĐÐ. Ú ² [1] Lu D M. Powder Metall Ind, 2002; 10(6): 30 ( ÊÂ. Å ß, 2002; 10(6): 30) [2] Maneshian M H, Simchi A, Razavi H Z. Mater Sci Eng, 2007; A445 446: 86 [3] Hwang K S, Huang H S. Mater Chem Phys, 2001; 67: 92 [4] Gusmano G, Bianco A, Polini R, Magistris P, Marcheselli G. J Mater Sci, 2001; 30: 901 [5] Raghu T, Sundaresan R, Ramakrishnan P, Ramamohan T R. Mater Sci Eng, 2001; A304 306: 438 [6] Peng X L. Mater Sci Eng, 1999; A262: 1 [7] Wang H Q, Li X H, Guo H J, Zhang B, Guo Y X. J Cent South Univ(Sci Technol), 2003; 34: 615 (Ë Ñ, ²Ù, ¼ Æ,, ¼²Ü. ËÊ «( Ü ), 2003; 34: 615) [8] Sharma R, Agarwala R C, Agarwala V. Appl Surf Sci, 2006; 252: 8487 [9] Lee W, Yang H J, Reucroft P J, Soh H S, Kim J H, Woo S L, Lee J. Thin Solid Films, 2001; 392: 122 [10] Shukla S, Seal S, Akesson J, Oder R, Carter R, Rahman Z. Appl Surf Sci, 2001; 181: 35 [11] Meenan B J, Brown N M D, Wilson J W. Appl Surf Sci, 1994; 74: 221 [12] Huang H Z. The Surface Chemical Analysis. Shanghai: East China University of Science and Technology Press, 2001: 21 (ÀÁ.. Å : Ð Ê, 2001: 21)