21 w t œwz J. Kor. Inst. Surf. Eng. Vol. 42, No. 1, 2009. < > PET»q SiO 2 rd ITO» Ÿw p a, ½ a, ³ a, a, y b a» w œw, b ( ) w p A Study on Adhesion and Electro-optical Properties of ITO Films Deposited on Flexible PET Substrates with Deposition of SiO 2 Buffer Layers Ja-youn Kang a, Dong-won Kim a, Kyu-il Cho a, Byung-il Woo a, Hwan-jun Yun b a Department of Advanced Materials Engineering, Kyonggi University, 94-6, Yiui-dong, Yeongtong-gu, Suwon-si, Gyeonggi-do, 443-760, Korea b Samhan Electronics, 401-1, Yeongcheon-ri, Dongtan-myeon, Hwaseong-si, Gyeonggi-do, Korea (Received February 9, 2009 ; revised February 26, 2009 ; accepted February 27, 2009) Abstract 7UKPI CP GXCRQTCVKQP U[UVGO 5K1 YCUFGRQUKVGFCUCDWHHGTNC[GTDGVYGGPC2'6UWDUVTCVGCPFC+61 NC[GT CPF VJGP +615K1 2'6 NC[GTU YGTG CPPGCNGF HQT JQWTU CV VJG VGORGTCVWTG QH Q % #FJGUKQP CPF GNGEVTQQRVKECN RTQRGTVKGU QH +61 HKNOU YGTG UVWFKGF YKVJ VJKEMPGUU XCTKCPEG QH C 5K1 DWHHGT NC[GT #U C TGUWNV QH KPVTQFWEVKQP QH VJG 5K1 DWHHGT NC[GT UJGGV TGUKUVCPEG CPF TGUKUVKXKV[ KPETGCUGF CPF C +61 HKNO YKVJQRVKOWOUJGGVTGUKUVCPEGΩUSWCTGHQTCPWRRGT+61HKNOQHTGUKUVKXGV[RGVQWEJRCPGNEQWNF DG QDVCKPGF YJGP 5K1 QH YCUFGRQUKVGF#PFKVYCUHQWPFVJCV+61HKNOUYKVJ5K1 DWHHGT NC[GT JCXG JKIJGT VTCPUOKVVCPEG QH ` CV PO YCXGNGPIVJ VJCP +61 HKNOU YKVJ PQ DWHHGT NC[GTU CPF VJG VTCPUOKVVCPEGYCUGPJCPEGFCU5K1 VJKEMPGUUKPETGCUGFHTQO VQ #FJGUKQPRTQRGTV[QH+61HKNOU YKVJ5K1 DWHHGTNC[GTUDGECOGDGVVGTVJCP+61HKNOUYKVJPQDWHHGTNC[GTUCPFVJKURTQRGTV[YCUKPFGRGPFGPV QH 5K1 VJKEMPGUU XCTKCPEG ` $[ FGRQUKVKPI C 5K1 DWHHGTNC[GTQH QPVJG2'6UWDUVTCVGCPF URWVVGTKPI C +61 VJKP HKNO QP VJG NC[GT C +61 HKNO YKVJ GPJCPEGF CFJGUKQP GNGEVTQQRVKECN RTQRGTVKGU EQWNF DG QDVCKPGF Keywords: ITO(Indium-Tin-Oxide), PET, SiO 2 buffer layer, Adhesion, Touch screen 1. ITO(Indium-Tin-Oxide) n-type p y ƒ Ÿ Ÿ n û» w ùkü» k (solar cell), v (liquid crystal display), leq (touch panel) n, Ÿ(electro-luminescent), t, w š 1). Corresponding author. E-mail : dwkim@kyonggi.ac.kr»q wš q,»q Ì w w w w» w acryl, polycarbonate(pc), polypropylene (PP), polyethylene terephthalate(pet), polyethersulfon (PES) n v p»q ITO w» w ƒ y š 2-6). ITO», Ÿw p»» w e, ü» w»q
22 /w t œwz 42 (2009) 21-25 j w 7-9) ITO t w hillock, hole w Ÿw p y j 10). leq ITO», Ÿw p w j š, ü w j» w PET»q ITO rd w. w rd» ù, SiO 2 rd w. evaporation system w PET» q SiO 2 rd wš, DC p rl w ITO w z œ w SiO 2 rd ITO», Ÿw, p y wš, w. 2. x PET»q SiO 2 rd w» w evaporation system w š, j» 2~3 mm, 99.99%, SiO 2 w. PET»q j»ƒ 190Ü250 mm, q» acetone 10, alcohol 10 10 z w ƒ evaporator ƒ» k w. w œ t 1 ùkü evaporator ü œ œ k rv 1.3Ü10 Torr¾ œ x w 3 z, l rv š œ y rv w 3.0Ü10 Torr» œ 5 w š, r» r w w Ar 15 sccm, O 2 25 sccm w»q w. SiO 2 œ Ì w Inficon Table 1. Process conditions of evaporation 2CTCOGVGTU 2TQEGUUEQPFKVKQPU /CVGTKCNU 5K1 ITCPWNGV[RG $CUG2TGUUWTG 6QTT 9QTMKPI2TGUUWTG 6QTT )CU #TUEEO1 UEEO 6GORGTCVWTG Q % &GRQUKVKQPTCVG U &GRQUKVKQPVJKEMPGUU deposition controller(ic/5) w SiO 2 2 /sƒ w š, k ̃ 50, 100 w w. PET»q SiO 2 rd z rl ITO w. w DC p rl k rv j rvƒ l DC q œ w» w 2.2 kw» w v x g. ITO k y (In 2 O 3 ) y (SnO 2 ) 10 wt% w y 166Ü380 mm j» ƒ r 60 mm e g. ITO w SiO 2 ƒ PET»q rl 16ƒx (jig) w w š jš, ƒ 5.22 Hz z w w ITO 30 /s w. ITO rl œ t 2 ùkü» œ 2.5Ü10 Torr 5 w š, ƒ O 2 / (Ar+O 2 ) 2%ƒ w, 2.5Ü10 Torr w 3 150 Ì w. ITO/SiO 2 /PET r w e 20Ü35 mm j» w z œ w w. w 1.0 Ü10 Torr¾ œ x w z ƒ 3 w 1.0Ü10 Torr œ 1 w š, 1 œ 5 o C/min, 180 C o 90 w z þƒw. ITO»q p w scratch test(scratch tester; CSM-instruments, SB-A64) water boiling test w š, ITO» Table 2. Process conditions of DC magnetron sputtering 2CTCOGVGTU 2TQEGUUEQPFKVKQPU 6CTIGV +61+P 1 5P1 5WDUVTCVG 2QN[GVJ[NGPGVGTGRJVJCNCVG2'6 $CUGRTGUUWTG 6QTT 9QTMKPIRTGUUWTG 10 3 6QTT &GRQUKVKQPICU 1 #T1 2TGURWVVGT OKP &%RQYGT M9,KI4QVCVKQP5RGGF *\ 5WDUVTCVGVGORGTCVWTG 4QQO6GORGTCVWTG &KUVCPEG OO 6JKEMPGUU CDQWV
/w t œwz 42 (2009) 21-25 23 Fig. 1. diagram of annealing process. p w w(four-point probe; Chang min tech, CMT-SR1000N), e (hall effect measurement system; Accent, HL5500) d w. w r Ÿw p w 550 nm ƒ Ÿ n (UV- VIS spectrophotometer; Uvikon, 941plus) d w š, x (FE-SEM; Jeol, JSM-6500F) w t x w. 3. š PET»q w SiO 2 ƒƒ 0, 50, 100 wš, DC p rl w ITO 150 ƒƒ w z ww, rd SiO 2 Ì ITO», Ÿw, p y. ITO» p y» w four-point probe w w d w, 2 SiO 2 rd ̃ 0, 50, 100 f w ƒƒ 188.9 Ω/ square, 529.3 Ω/square, 602.3 Ω/square f Fig. 3. Carrier mobility and concentration of ITO films with thickness of SiO 2 buffer layers deposited on the PET substrates. š, p SiO 2 rd z w j ƒ w. SiO 2 Ì w y ew, w» w Hall effect measurement system w e d w. 3 ùkü SiO 2 rd 50, 100 w SiO 2 rd w e ù e j û, SiO 2 rd PET l ITO ITO ü e ƒ w, z ITO rl»q ITO w y ƒ Sn w e ƒ x ù, SiO 2 rd» q e ƒ û q. SiO 2 rd Ì ITO Ÿw p y» w UV-VIS spectrophotometer Fig. 2. Sheet resistance and resistivity of ITO films with thickness of SiO 2 buffer layers deposited on the PET substrates. Fig. 4. Transmittance at 550 nm wavelength of ITO/ SiO 2 /PET layers with thickness of SiO 2 buffer layers.
24 /w t œwz 42 (2009) 21-25 Fig. 5. Critical load of ITO films with thickness of SiO 2 buffer layers deposited on the PET substrates. w ƒ Ÿ 550nm q n d w š, 4 ùkü. SiO 2 rd w r w w r Ÿn 3~5% w š, p rd ̃ ƒ w Ÿn. Ÿn w j» w r û w, SiO 2 rd r ITO wì w x g»q w û n w k q 11). SiO 2 rd PET»q ITO p y» w scratch test water boiling test(wbt) w. 5 ùkü scratch test, critical load (Lc) nano indentorƒ load ƒ r ù r ƒ ù load w, š w. SiO 2 rd 0, 50, 100 w critical load ƒƒ 9.14 mn, 12.2 mn, 11.9 mn ùkþ, ITOd ( 150 ) d e ù, SiO 2 r d p w š, w p rd Ì q. r p w y» w water boiling test(wbt) w š, 6 ùkü. WBT ò r ƒ 1~2 ò z ee l v r û p d w l p d r w y w g d w Fig. 6. SEM images before and after WBT(water boiling test) of ITO films with thickness of SiO 2 buffer layers deposited on the PET substrates: (a) ITO/ PET before WBT, (b) ITO/PET after WBT, (c) ITO/SiO 2 50 /PET before WBT, (d) ITO/SiO 2 50 ç/pet after WBT, (e) ITO/SiO 2 100 /PET before WBT, (f) ITO/SiO 2 100 /PET after WBT.. 6 (a), (c), (e) ƒƒ SiO 2 rd 0 ç, 50 ç, 100 ç ITO d t x ùkü š, (b), (d), (f) (a), (c), (e) r ƒƒ WBT w z ITO d t ùkü. SiO 2 rd Ì ITO r» w, rl w w ƒ ƒ w q»q t w y y x ƒw 12). w 6(b) SiO 2 rd ITO WBT z t ³ wš w ù, SiO 2 rd ƒƒ 50, 100 ITO 6(d), 6(f) w WBT
/w t œwz 42 (2009) 21-25 25 /z t y. w SiO 2 rd w PET»q ITO w j, p rd Ì q. PET»q ITO SiO 2 rd w ITO w w ƒ w ù, SiO 2 rd 50 529.3 Ω/square w w leq d ITO v w 500Û100 Ω/square k. w SiO 2 rd ̃ 0 100 ƒw 550 nm q Ÿw p w, SiO 2 rd PET»q ITO ƒ w š, w p rd Ì ùkû. v leq ITO p w SiO 2 rd w ITO w w ƒ Ÿ n,»q w w leq w w š q. 4. leq ITO», Ÿw p w j š, ü w j» w PET»q SiO 2 r d wš, ITO rl w z œ w SiO 2 rd ITO», Ÿw, p y wš, w. SiO 2 rd ITO w w ƒw ù, ITO» p w le q w p ww š, SiO 2 rd ̃ 0 100 ƒw Ÿw p w, SiO 2 rd PET»q ITO ƒw. SiO 2 rd w ITO w leq ww š q. š x 1. W. C. Song, J. of KIEEME (in Korean), 17 (2004) 1277. 2. B. S. Chiou, S. T. Hsieh, and W. F. Wu, J. Am. Ceram. Soc., 77 (1994) 1740. 3. A. K. Kulkarni, K. H. Schulz, T. S. Lim, and M. Khan, Thin Solid Film, 270 (1997) 1. 4. T. Minami, H. Sonohara, T. Kakumu, and S. Takata, Thin Solid Film, 270 (1995) 37. 5. W. F. Wu and B. Shiou, Thin Solid Film, 298 (1997) 221. 6. A. K. Kulkarni, T. S. Lim, M. Khan, and K. H. Schulz, J. Vac. Sci. Technol., A16(3) (1998) 1636. 7. Y. S. Huang, W. Q. Qiu, and C. P. Luo, Thin Solid Film, 472 (2005) 20. 8. M. R. Kreke, A. S. Badami, and J. B. Brady, Biomater, 26 (2005) 2975. 9. J. E. Gray, P. R. Norton, and K. Griffiths, Thin Solid Film, 484 (2005) 196. 10. T. Wu, W. Xiaolong, W. Yutao, and D. Longjiang, RARE METALS, 25 (2006) 65. 11. Y. Zhinong, L. Yuqiong, F. Xia, Z. Zhao, and W. Xue, Thin Solid Film, Available online (2009). 12. K. Y. Hwan, y w w», 12 (2001) 1169.