Korean Chemical Engineering Research

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(1)Korean Chem. Eng. Res., Vol. 43, No. 1, February, 2005, pp. 98-102. CVDà £¿ |C ·÷£ §¿ <

(2) Z ô | K§ ;·. ? kûX+ <· L* `. †. M¬H/ àê¬H ÄdHàHz, ñkõC, *UéàHz 500-757 ?Q {C Äó 300 (2004¸ 12ö 27³ [¤, 2005¸ 2ö 18³ >) Surface Morphology and Hole Filling Characteristics of CVD Copper Duk-Soo Kim, Changshin Sunwoo, Don-Hee Park, Jin-Hyuk Kim* and Do-Heyoung Kim† Department of Chemical Engineering and The research Institute of Catalysis, *Department of Materials Science & Engineering, Chonnam National University, 300, Yongbong-dong, Buk-gu, Gwangju 500-757, Korea (Received 27 December 2004; accepted 18 February 2005). ß È. á õCÑ2 K, MC¯(HFAC)Cu(DMB)s «ÄGñ C-õ fÆGÊ, ,¶5 Ú ®1Ã dYí« ô C-L ,

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(6) ÁêÍ . Abstract − This article describes a study of chemical vapor deposition (CVD) of copper thin films on TiN substrates using (HFAC)Cu(DMB) as a precursor. The surface morphology and conformality of the Cu films as functions of substrate temperature and the presence or absence of iodine have been investigated. The surface roughness was increased significantly along with decrement of the step coverage by increasing the deposition temperature. The highest conformal films with the lowest surface roughness were obtained using the process of copper CVD, where iodine vapor were discretely introduced into the reactor during the growth of copper. Key words: Copper, CVD, Conformality, Surface Morphology. 1.. C «. Ê Î2 @'»«÷ £D U o Î¤G÷ èHK gh@ s ñDO ¤ À2 g- H@ « Mfæ´t G(M g), åMg o L Í kÎ .-2 Y« À. « 6K Î à_Ë éfYË³ ¯Gñ é2 g- áJ¯ ä Ä« @æÊ À. «Q ç« g-ô D¬ ´sÞ« 4 À{Ñ gGÊ IC É ¿D2 @Jk³ Ê4@Ê Àk, «Ñ !¶ g- Ä 1® o Yó ¿j ¬æÊ À. -Ê U¾ @'»«÷ £D U « Î¤K g- ô D¬ íè eÝÍ K s«. ³ä Jk³ dHô D¬(chemical vapor deposition, CVD)o ñ ô D¬Ñ WGñ @'»ê £D U « Î¤K D¬³ <s À . !¶ 90¸ «á g- CVD õg2 A2C«÷ D¬ \ @:j lèK õgÍ D}æ´ f[1-3]. 6÷ Qo õgÍ D }æ´ f{Ñ gGÊ éb@ g- CVDD¬o D¬J ¥Í 4 HÉ fÆÑ JÄæÊ À@ :. cê «K³ 2 o ô Q Wÿ eö@L .Ñ Lê g- ,

(7) « kÎ Mr2 Ys Ë ¤ À[3].. ä É RJ ¬³ gÆÍ @gÆ(multilevel metallization)d æ

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(10) uñ Ê Ú ê É 8_ eÝõ .Gñ DÊ cê é0¯ <PÂ« WI]« o g-³ Yó ¬æ´ ÍÊ Àk, «Ñ !¶ gô D¬ íèÑ Qo î« RyæÊ À. é ä Éf Æõ .K g- áL D¬³ ³z ÄæÊ À2 D¬o íJ ô à_¯ A2C(sputtering)ê U r¯ à_«. 6÷ A2C(sputtering) à_o ÊKK AD k³ ¯Gñ ÷ô ¿D ®{ z~(É >«÷ W´(via) gá)Ñ ®gG2 ¤ g @'»(step coverage)ê £D U s OÇ ¤ Ç. † To. whom correspondence should be addressed. E-mail: E-mail: [email protected]. ‡. « øéo õ§¬0/ 6ÎR /¤ _¸s ,Ä/ñ ·ÊæÉ5n. 98.

(11) CVD. C-L ,

(12) Ú £, 7 õC. g- CVD L Í o ao c³ Äæ2 1Í Mg ô èn« disproportation äk³ äDÑ K½ê Mg ÁS« M¬ 50%õ s ¤ ÇD Aé«. 6÷ É ° « @Ý Ê4H Î £DO gá z)Í k´ÍÑ !¶ . 1 L 2 á f Ä Ã éfÍ æ@ :s ak³ ê. !¶ g- CVDÑ ggt O M¬ éfYo ô g-L Mn ,

(13) s f´GÊ k«2 a«¶ O ¤ À. éb @ CVD g-L ,

(14) MrDõ íGD .g K í-, d HJ ,

(15) s- ör« fæ´ f[3-7]. ñ6 Í@ ör y ® 1Ãõ «ÄGñ ô g-L ,

(16) MrDõ íG2 Whangê Lee ê2 kÎ KÄK örk³ ¶ê. Whangê Lee2 g - 1Í Mg¯ Cu(I)-hexafluoro acetylacetonate-vinyltrimethylsilane [(HFAC)Cu(VTMS)]õ «ÄK g- CVDªÑ ®1Ã2 g- hdõ èHGj GÊ, õJ¯ L« «P´@2 »ª &ÿõ 2 ÁêÍ ÀÊ ÝÊGÊ À[6, 7]. á õgÑ2 h ÷ôº¶ Ñ íèê Cu(I)-hexafluoroacetylacetonate-3,3-dimethyl1-butene[(hfac)Cu(DMB)]õ ÄGñ DðJ ¯ L U s oÝIk, U¾ ®1Ã s- örÑ !ñ ô g-L ,

(17) ¡dQ Wÿ ®1Ã s-Ñ !ñ g- £ D U Ñ ¬Gñ oÝI. 2.. / . 99. , E Às@ Hí2 îÑ Mg ~gõ MdGD .g `6Q JîäÃ M-õ ij(-10 cm) G. g- ô s .K D¶o Si(p-type)\SiO (3000Å)\TiN(A2÷ TiCl õ «Ä Gñ fÊê CVD TiN)s ÄGk, ¶ D¶ê Wÿ £D U s +_GD .g gá« ê Ò¡ D¶s ÄG. Ò ¡ ¿D2 ½g A 0.25 µm, _«Í 1.0 µmk³ Ü·W(aspect ratio)2 4«É. CVD à_ Fto 1.0 torr «ÉÊ, `6 52 40 C, Mg Òî 52 Mg ö@õ .Gñ 50 C³ K@G. Mg ÒD2 ¤ 60 sccms Ä GÊ, 80-225 C p.Ñ 1-10~Ñ g- CVDõ G. ôê so o 5Ñ ¬Dô æ2 dõ ö@GD .Gñ Ê DàGÑ 5b@ 5õ 1 äDÑ â,k, × é s K @GD .Gñ k × á îê äDõ ÍùG

(18) 1Ñ _ äD zõ B?(evacuation), ÍÊK ¨íËs fMG2 ª õ MÅ. ôê g- &ÿQ ,

(19) , £DU s +_GD .Gñ scanning electron microscopy(SEM) ~ê Wÿ atomic force microscopy(AFM)s D}G. g- ¨ +_o AES (auger electron spectroscopy), áL WI]o 4Y é³ -Ê áL _ o X-ray diffraction(XRD)s ÄGñ ÍG. 2. 4. o. o. o. 3.. ûG Z +{. á ×Ñ2 ÄK CVD äD2 É fÊK IF - dH ôD³ AÊ í÷õ Fig. 1Ñ ÷ É äD2 Aº¯-A éH³ æ´ Àk, e DàBéõ. ÄGñ k × M ðD Dàs 5×10 torr «G³ K@G. ¾2 I] Íùk³ s 5 è³ s K@GD .Gñ < PÂk³ fÊK ¹(susceptor)õ ÄG. -Ê ô 5 +_ Ú f´õ .g2 <PÂ ¹Ñ éê J ù Mµê PID f´Dõ «ÄG. s 52 ¥³ ×s D }Gñ ¹Q s 5 îîª ,õ gGñ Ñ[Jk³ +_G. ×Ñ ÄK Mg2 h ÷ôº¶ (¯])Ñ g½K(hfac)Cu(DMB) [(hexafluoroacetylacetonate)Cu(3,3-dimethyl-1butene)]³, g½K á

(20) « _fW Ç« ¬³ ÄG. « Mg2 5Ñ ´&Ò Õ+s 2 U« ~É

(21) o 354.76 g «Ê, 40 CÑ DFo u 2.0 torr«. «2 «fb@ c³ Ä æ´ 5 g- Mg¯(HFAC)Cu(VTMS)Í 40 CÑ u 0.3 torr _¯ as ÊsG

(22) DF« ¢¾ {s < ¤ À. `6 Ñ À2 Mg2 ÒDõ «ÄGñ äDÑ «æÉk. ÎJk³ DáJ¯ ô U s oÝD .g ô 5Ñ ! ñ g- L õ oÝI. åÈÝ g- ô« ÍD K MIYs oÝD .Gñ I5 ò¯ 60 CÑ 1Ñ 8 Mgõ äDÑ K½G. L8k³2 g- ô Js å ¤ ÇÉk÷, SEMk³ e¯K ê D¶.Ñ ~ê g- ½ÉËs î+O ¤ ÀÉ. !¶ ô Ñs Lj O Î 60 CÑ g-Í Lî ¤ À{s < ¤ ÀÉ. Fig. 22 D¶ ô5Ñ !ñ ô ¡dõ ÝñcÊ À2), ,

(23) ä S òê íHM S ò« g~æ2 160 C Ñ M¬ u 50 nm/min L Í ÍDG. 160 C « Ñ ô Í D¶ 5 ÍÑ !¶ Ýæ2 o Mg. Fig. 1. A schematic diagram of the copper CVD system.. Fig. 2. The effect of deposition temperature on film growth rate.. (cold wall type) .. −6. o. o. o. o. o. o. Korean Chem. Eng. Res., Vol. 43, No. 1, February, 2005.

(24) 6 ¤öÎ Uöáö6,ö6. 100. Fig. 3. The effect of deposition time on film thickness at (a) 100oC and (b) 120oC.. D ~g äk³ ¯K ê¶ O ¤ À. !¶ âo £' » U s »D .g2 ,

(25) ä S ò¯ 160 C «GÑ ô« 1®Ws < ¤ À. ,

(26) ä S òÑ g- ô s .K l dÑw@2 0.57 eV³ ÷

(27) . {k³2 ,

(28) ä S òÑ g- ß Í _ = ¯@ ñzõ <4ÝD .Gñ 100 CQ 120 CÑ ô Ñs 3-10~k³ ¡dE ÝI. Fig. 3Ñ å ¤ À×« ô Ñ« ¬öÑ !¶ Lê g- &ÿÍ Jk³ ÍWs < ¤ À Ê, «2 á g- ô ÆQGÑ g- ß« _ =³ «P´ Ps ÷. 6÷ Ls .g2 u 1-2~ ÙéÑ (incubation)« ÊéG. «Q ço ÙéÑ Êé2 g- hd õ .g 1®K Ñw@Í hdê g- ßs .g 1®K Ñw @Ý Ã as ÷, K TiN .Ñ g- `{ (wetting) « â@ :{s ÷. «Q ç« e ö@L .Ñ ù5K g- `{ o h ô g-L ,

(29) s Mrj G2 y®K ò¯ « ê. -Ê Mg ÜÍ÷ D¶ ÜÍÑ !¶ ÙéÑ« ¶D. g- ù5K `{ s íGD .Gñ MÑ Senkevich Ù[10]o ¯(P)s «ÄK g- e ö@L Ms-Í ÁêJ«¶Ê ÝÊGÊ À. 6÷ ¯ Î g- ¨ í³ ÊÄGD AéÑ áJ¯ éf g ¬8o î ¤ Ç. g- áLs ä Ñ ÄGÊÉ O A, Íß y®æ2 L U o WI] à«. ôê g-L ô 5Ñ !ñ WI ] U às u 2,000Å &ÿ ss ÄGñ oÝI. I5 òÑ2 Lê g- WI] ào 5Í s¤´ Ýæ´ Í2 s Ýk÷, 140 C « 5Ñ2 5Ñ !ñ W I]à ¡dÍ ÂÂGÊ, 200 C « Ñ2 1¾s à« Q « ÍG. 140-200 CÑ ôê Cu WI] ào u 3 µΩcm k, «2 h¿ g- I]à 2 _«. ³äJk³ W I] ào áL ê ¨Ñ ¿j æÎÍ æ2), 100-200 C Ñ ôê sË ¨2 AES ~ ê 100%Ñ ÍbÒ Ê¨ . !¶ h¿I]Ñ WGñ ¬Jk³ o á × ê2 ôL Ñ K a»s < ¤ À. f Fig. 4(e)Ñ å ¤ À×« 200 C « Ñ2 _? «³ kÎ Ã à« Ê éWs å ¤ Àk, «6K à o D ~g³ ¯K go. o. o. o. o. o. o. o. ¤@¤ C43× C1 2005 2. Fig. 4. SEM micrographs of the Cu films deposited on TiN at (a) 80oC, (b) 120oC, (c) 140oC, (d) 160oC, (e) 200oC and (f) 220oC.. ½É ê Wÿ ¬Jk³ uñ g-½É ,

(30) «ê³ _ê. Fig. 42 ô5Ñ !ñ Lg- ,

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(33) s gGD .g2 o L 5Í K-Ws < ¤ À. !¶ ,

(34) ä S ò¯ 160 C «G¯ 5Ñ Whangê LeeÍ ÄG Ñ ®1Ã(C H I) õ ÄGñ ®1Ã ñkJ¯ ª

(35) l U s ÍG. ,

(36) MrD í Áê s oÝD .Gñ {ê ço § Í@ ®1 Ã s- ös ÍGñ ÝI. d~2 TiN D¶s g- ô M ³_Ñ Ñ®1Ã³ s-K á g- ôs D}G2 Î« , & d~2 Ñ ®1Ãõ MgQ Ñ c½G2 Î, Ê § d~2 TiN .Ñ g- ôs io Ñ D}K á ®1Ã dYí³ g-,

(37) .õ s-GÊ, g-õ ôK Î«. ×ê g- ôM TiN D¶s ®1Ã dYí³ Ms- K Î Ñ2 ®1Ã dYís ÄG@ :o ÎQ Ã ó«Í ÇÉ. « 2 C H I ~gä« TiN D¶ .Ñ2 «P´@@ :4 ®1 Ã ñkJ ª

(38) l Áêõ »s ¤ ÇD Aé«. !¶ á ×Ñ2 & d~Q § d~ Îõ WGGñ oÝI. DÝ Êê õgêÑ G

(39) C H I2 120 K o 5Ñ g- . Ñ C H Q I ³ ~gæÊ, ~gê C H 2 -200 KÑ A è « Ã ÑW(C H )ê H ³ ~gæ, ôê H 2 -250 K Ñ H ³ ¡dGñ ,

(40) k³z %ôGj êÊ K[11]. ®1Ã dYís MgQ Wÿ äDÑ K½E CVDõ D} K Î ®1Ã dYís ÄG@ :o ÎÝ k6Ò ,

(41) s o. o. o. 2 5. 2 5. 2 5. 2. 5(ad). (ad). 2. 2. 2 5(ad). 4. (ad). (ad).

(42) CVD. C-L ,

(43) Ú £, 7 õC. 101. Fig. 6. Cross-sectional SEM photos of the copper films deposited on the patterned substrate (hole size: 0.25 µm): (a) only with Cu precursor, (b) with simultaneous usage of Cu precursor and C2H5I, (c) with only Cu precursor in the beginning of the deposition following only C2H5I adsorption for 30 s and then with only Cu precursor, and (d) with only Cu precursor in the beginning of the deposition following only C2H5I adsorption for 3 min and then with only Cu precursor.. íËs ~O c½K § d~ ÎÝ ô Í u 15% _ Ýê ao «6K _s Ñ çzK. ôL WI] (resistivity)o C H I s-G@ :o ÎÝ 5-15% _ WI] à « ÝæÉ. AES ~ ê ®1Ãõ s-K g- LÑ ®1 Ã÷ ñ ¨í« ]æ@ :ID AéÑ WI] à Ý2 ® 1Ãõ ÄGñ ôê g- _? õ , jÊÍ í ê ê³ O ¤ À. 120 CÑ ôê 1,000Å &ÿ ô g-L WI](resistivity)o C H Iõ s-õ s-G@ :o Î u 5 µΩcm WI]às ÷Ék÷, ®1Ãõ !³ s-K § d~ Î u 3.5 µΩcms ÷É. K@Lk³ «6K ®1Ã dYí ,

(44) MrD í ÁêsF gá £D U Ñ âo s c2@õ oÝI. ô5 Í s¤´ £D U « ù5g @2 × êÑ MGñ ®1 Ã Áê ×s .K 52 ,

(45) S ò¯ 120 CÑ D} G. Fig. 6Ñ å ¤ À×« ®1Ãõ ÄG@ :o Î £ D U « ù5Ws < ¤ À. ®1Ã dYíê Mgõ Ñ K½K & d~ Î s-õ G@ :o ÎQ WG £D U « íæD2 Gk÷, L zÑ ôê g-LÑ Qo àÑ« Ê éWs å ¤ À. Íß âo £D U o ,

(46) MrD íÁêQ ³Gj ÏI äD³ g-Mgõ sc´ D¶Ñ g- hs @ K á ³_Ñ C H Iõ -Ê, g- Ls D}K ÎÑ »s ¤ ÀÉ. 6÷ C H Iõ sc2 Ñ« wå io Î £D U í Áê « ©´@, á ×ÆQÑ2 M 3~ « C H I K½ Ñ« 1®G. 2 5. o. 2 5. Fig. 5. AFM images of the copper films deposited at 140oC: (a) only with Cu precursor, (b) with simultaneous usage of Cu precursor and C2H5I, and (c) with only Cu precursor in the beginning of the deposition following only C2H5I adsorption and then with only Cu precursor.. ä2 g-õ »s ¤ ÀÉ. 6÷ g-ôs ij K á ®1Ã dYís ÄK § d~ ÎÝ2 ¬Jk³

(47) Mn ,

(48) s Í@Ê À. Fig. 52 ®1Ã s- öÑ !ñ ôL ,

(49) M rD ¡dõ Ýñc, g-2 140 CÑ ôæÉ. AFMs « ÄGñ ô g-L ,

(50) MrDõ Íg ÝI2), Ms-õ G @ :o Î ,

(51) MrD(RMS)2 229Å «É@O, & d~Q § d~ Î2 ÎÎ 152(34% Ý), 180Å(21% Ý)«É. Ê «6K ,

(52) MrD ío U«Gj íHM S ò¯ 180 CÑ ³K s ÷É. -Ê g- ô 2 ®1Ã dYís ÄK & Î H & ÝG. «sF ®1Ã dYís ÄO A ô Í Ý G2 «K2 C H IÍ D¶ .Ñ Læ2 g- ,

(53) ôY s YKGñ Mg ôs ögK ê³ _ê. U¾ Mg Q ®1Ã dYís Ñ äDÑ K½K & d~ ÎÍ ä o. o. 2. 5. o. 2. 5. 2 5. 2. 5. 4.. û «. õ «ÄK CVD Cu õg ê, ®1Ã dYí. Ä« ,

(54) MrD íê £D U Ñ _J¯ s g2 as < ¤ ÀÉ. «A ®1Ã dYíê Mgõ Ñ äD (hfac)Cu(DMB). Korean Chem. Eng. Res., Vol. 43, No. 1, February, 2005.

(55) 6 ¤öÎ Uöáö6,ö6. 102. Ñ K½O ÎÝ g- hdõ D}K á ®1Ã dYí³ ³_ Ñ ô g-Ls s-K á, g- ôs D}O A Á ê « Íß . á × ÆQÑ2 £D U ís .g 1® K M ®1Ã s- Ñ« 3~«Ék, ®1Ã s-2 ô g -L WI] íÑ _J¯ Áêõ ÷É. 6÷ TiN eö@Ls ®1Ã dYí³ s-G2 ÎÑ2 ,

(56) MrD Ú £D U íÑ ÁêÍ ÇÉ.. [ ÷ « øéo KhH¬Dé õgêf(KRF-2001-042E00078)Ñ Gñ õgæÉk «Ñ Ý õ Ã?n.. +S 1. Chang, C.-L., Lin, C.-L. and Chen, M.-C., “Effect of TiN Substrate Plasma Treatment on Copper Chemical Vapor Deposition,” Jpn. J. Appl. Phys., Part 1, 43, 2442-2446(2004). 2. Awaya, N. and Arita, Y., “Double-level Copper Interconnections Using Selective Copper CVD,” J. Electronic Mat., 21, 959-964(1992). 3. Kim, D. H., Lee, Y. J., Park, C. O., Park, J. W. and Kim, J. J., “Nucleation Reactions and Film Growth of Copper on TiN using Hexafluoroacetylacetonate Copper(I) Trimethyl-Vinylsilane,” Chem. Eng. Comm., 152, 307-317(1996). 4. Doppelt, P., Semaltianos, N., Deville Cavellin, C., Pastol, J. L.. ¤@¤ C43× C1 2005 2. and Ballutaud, D., “High Affinity Self-assembled Monolayers for Copper CVD,” Microelectronic Engineering, 76, 113-118(2004). 5. Josell, D., Wheeler, D. and Moffat, T. P., Electrochem and SolidState Lett., Superconformal Deposition by Surfactant-catalyzed Chemical Vapor Deposition, 5, C44-C47(2002). 6. Hwang, E. S. and Lee, J., “Surfactant-Catalyzed Chemical Vapor Deposition of Copper Thin Films,” Chem. Mater., 12, 2076-2081 (2000). 7. Hwang, E. S. and Lee, J., “Surfactant-Assisted Metallorganic CVD of (111)-Oriented Copper Films with Excellent Surface Smoothness,” Electrochem. and Solid-State Lett., 3, 138-140 (2000). 8. Choi, K-K., Pyo, S. G., Lee, D. W. and Rhee, S-W., “Metalorganic Chemical Vapor Deposition of Copper using (hexafluoroacetylacetonate)Cu(I)(3,3-dimethyl-1-butene) with a Liquid Delivery System,” Jpn. J. Appl. Phys., Part 1, 41, 2962-2968(2002). 9. Choi, K.-K. and Rhee, S-W., “Effect of Carrier Gas on Chemical Vapor Deposition of Copper with (hexafluoroacetylacetonato) Cu(I)(3,3-dimethyl-1-butene),” J. Electrochem. Soc., 148, C473-C478 (2001). 10. Senkevich, J. J., Yang, G. R., Lu, T. M., Cale, T. S. Jezeweski, C. and Lanford, W. A., “Phosphorus Atomic Layers Promoting the Chemisorption of Highly Polarizable Transition Metallorganic,” Chem. Vap. Deposition, 8, 189-192(2002). 11. Lin, J. L. and Bent, B. E., “Carbon-halogen Bond Dissociation on Copper Surfaces: Effect of Alkyl Chain Length,” J. Phys. Chem., 96, 8529-8538(1992)..

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