未來研究方向

在第一章時曾提到，鋁材在歷經400℃以上的製程溫度時，與矽表 面會有相互擴散的情況發生，故在鋁與矽接觸的地方會形成所謂的突 穿現象；要解決此一現象，可以在鋁導線中加入適量的矽，使鋁對矽 的固態溶解度飽和，就可以減少突穿現象發生的機率。在本論文中，

利用鋁的摻雜加強銅膜的抗氧化性及擴散阻擋能力，對銅金屬導線製 程具有正面的幫助。而加入的鋁金屬與矽底材間的擴散作用，也是不 能忽略的，但因本文最主要是找出對銅原子具有最佳擴散阻擋能力的 薄膜，因此鋁與矽之間的相互關係也有待進一步之研究。

第二，擴散阻障層材料的選擇必須符合許多要求；其中，銅膜與 介電層或矽底材之附著性也是個相當重要的參數。金屬導線必然的多 層化發展，在鍍上第一層銅膜後，將還會有後續的化學機械研磨，介 電層沉積、金屬沉積和熱處理製程；另外，利用不同方式所沉積出來 的介電層薄膜或金屬薄膜也會有不同的應力表現。故在不斷的昇溫及 降溫的熱循環中，由溫度所產生疲勞會使得原本熱膨脹係數或應力就 不盡相同的各層材料增加了剥離的機會，對於薄膜的結構及電性的可 靠度會有相當大的影響。本文中原欲藉由鋁與銅的反應生成鋁銅基合 金，以鍵結力較強的金屬鍵取代離子鍵，直接提升擴散阻障層與金屬 薄膜的附著性；但至目前為止，並無有效方法可直接證實銅膜與 Ti-Al-N

的附著性增加與否。因此，擴散阻障層與介電層或矽底材之附著性的 探討和驗證也須再加以證實。

20 25 30 35 40 45 50

Intensity (Arb. Unit)

2θ (degree)

(111) (200) (111) (200) (111) (200)

(111)

圖 4.1 不同氮流量下所沉積的 Ti-Al-N 薄膜經 X 光繞射分析結果。

N2=0 sccm N2=1 sccm N₂=2 sccm N2=3 sccm

TiAl

SiO2

圖 4.2 氮流量為零所沉積的 Ti-Al 薄膜經穿透式電子顯微鏡觀察 分析的結果。

20 nm

0.0 0.5 1.0 1.5 2.0 2.5 3.0 3.5 4.0 15

20 25 30 35 40 45 50 55 60 65

Resistivity (μΩ-cm)

Nitrogen flow rate (sccm)

Ti-Al-N SiO2

圖 4.3 不同氮流量下所沈積的 Ti-Al-N 薄膜隨電阻率變化的情形。

0 100 200 300 400 500 600 700 800 -5

0 5 10 15 40 60 80 100 120 140

Annealing temperature (

^o

C)

Δ R

s

/R

s

N = 0 N = 1 N = 2 N = 3

圖 4.4 Cu/Ti-Al-N/Si 結構經不同溫度退火後片電阻率變化的情形。

圖 4.5 Cu/Ti-Al/Si 經不同退火溫度一小時退火後的 XRD 繞射圖。

圖 4.6 Cu/Ti-Al-N/Si 經不同退火溫度一小時退火後的 XRD 繞射 圖。

20 25 30 35 40 45 50 55

750^oC

700^oC

650^oC

600^oC as-dep.

2

θ

(degree)

Intenity (Arb. Unit)

Cu(111)

Cu(200)

Si

Al₅Ti₃(321)

AlTi₃(200)

TiAlN2(102) Cu₃Si(320)

0 50 100 150 200 250 300 350 400 10⁰

10¹ 10² 10³ 10⁴ 10⁵ 10⁶ 10⁷

Cu

Al Ti

Si

Secondary ion counts

Sputtering time (sec)

圖 4.7 Cu/Ti-Al /Si 經 550^oC 下退火 30 min 後的 SIMS 縱深分佈圖。

0 25 50 75 100 125 150 175 200 225 250 10⁰

10¹ 10² 10³ 10⁴ 10⁵ 10⁶ 10⁷

Ti Cu

Al

N

Si

Secondary ion counts

Sputtering time (sec)

圖 4.8 Cu/Ti-Al-N/Si 經 650^oC 下退火 30 min 後的 SIMS 縱深分佈圖。

Cu-Si Cu-Ti-Al

Cu

Si

圖 4.9 Cu/Ti-Al/Si 經 550^oC 下退火 30 min 後的 TEM 影像。

100nm

Cu

Ti-Al-N Si

圖 4.10 Cu/Ti-Al-N/Si 經 650^oC 下退火 30 min 後的 TEM 影像。

20nm

參 考 文 獻

[1] Shyam P. Murarka, “Multilevel interconnections for ULSI and GSI era”, Materials Science and Engineering, R19, 1997, pp. 87-151.

[2] M. M. Moslehi,A.P. Lino, T. Omsted, ”Ultralarge Scale Integrated Metallization and Interconnects”, J. Vac. Sci. Technology. A17 (4), 1999, pp. 1893-1897.

[3] S. P. Murarka and Steven W. Hymes, “Copper Metallization for ULSI and Beyond”, Critical Reviews in Solid State and Materials Sciences, 20(2), 1995, pp. 87-124.

[4] 莊達人，VLSI 製造技術，五版，台北，高立圖書有限公司，民國九十一年。

[5] 陳錦山，黃獻慶，鄭亦冠，「泛談銅內連接導線與低 k 介電層製程與特性」，

真空科技，第十二卷第二期，27-33 頁，民國八十八年七月。

[6] S. Vaidya, T. T. Sheng, A. K. Sinha, “Linewidth Dependence of

Electromigration in Evaporated Al-0.5% Cu.”, Appl. Phys. Lett., 36(6), 15 March 1980.

[7] R. L. Jackson, E. Broadbent, and T. Cacouris, “Processing and Integration of Copper Interconnects”, Solid State Technology, March 1998.

[8] Y.T. Kim,C.H. Jun,D.Y. Kim, ”Barrier Properties of TiN/TiSi2 Bilayers Formed Two-Step Rapid Thermal Conversion Process for Cu Diffusion Barrier”, Thin Solid Films, Vo.347, 1999, pp. 214-219.

[9] D. Pierce, J. Educato, V. Rana, and D. Yost, ”Wafer Level Electromigration Applied to Advanced Copper/Low-k Dielectric Process Sequence Integration”, IEEE IRW Final Report, 1998, pp. 10-15.

[10] S. Bothra, B. Rogers, M. Kellam, C.M. Osburn, “Analysis of the Effects of Scaling on Interconnect Delay in ULSI Circuits”, IEEE Transactions On

Electron Devices, Vol. 40, No. 3, March 1993.

[11] T. Sakurai, Member, “Closed-Form Expressions for Interconnection Delay, Coupling, and Crosstalk in VLSI’s”, IEEE Transactions On Electron Devices, Vol. 40, No. 1, January 1993.

[12] C.K. Hu, B. Luther, F.B. Kaufman, J. Hummel, C. Uzoh, D.J. Pearson, “Copper Interconnection Integration and Reliability”, Thin Solid Films, 262 (1995), pp.

84-92.

[13] S.W. Russell, S.A. Rafalski, R.L. Spreitzer, J. Li, M. Moinpour, F. Moghadam, T.L. Alford, “Enhanced adhesion of copper to dielectrics via titanium and chromium additions and sacrificial reactions”, Thin Solid Films, 262 (1995), pp.

154-167.

[14] Y.S. Diamand, A. Dedhia, D. Hoffstetter, and W.G. Oldham, “Copper Transport in Thermal SiO₂”, J. Electrochem. Soc., Vol. 140, No. 8, August 1993, pp.

2427-2432.

[15] X.W. Lin, and D. Pramanik, “Future Interconnection Technologies and Copper Metallization”, Solid State Technology, October 1998,pp. 63-79.

[16] F. Braud, J. Torres, J. Palleau, J.L. Mermet, C. Marcadal, E. Richard, “Ultra Thin Diffusion Barriers for Cu Interconnections at The Gigabit Generation and

Beyond”, Microelectronic Engineering, 33 (1997), pp. 293-300.

[17] C. Ryu, K.W. Kwon, A.L.S. Loke, H. Lee, T. Nogami, V.M. Dubin, R.A. Kavari, G.W. Ray, and S.S. Wong, “Microstructure and Reliability of Copper

Interconnects”, IEEE Trans. Elec. Device, Vol. 46, No. 6, June 1999, pp.

1113-1119.

[18] D.S. Gardner, J. Onuki, K. Kudoo, Y. Misawa, Q.T. Vu, “Encapsulated copper interconnection devices using sidewall barriers”, Thin Solid Films, 262 (1995),

pp. 104-119.

[19] G. Raghavan, C. Chiang, P.B. Anders, S.M. Tzeng, R. Villasol, G. Bai, M. Bohr, D.B. Fraser, “Diffusion of copper through dielectric films under bias

temperature stress”, Thin Solid Films, 262 (1995), pp. 168-176.

[20] A. Misra, M. F. Hundley, D. Hristova, H. Kung, T. E. Mitchell, M. Nastasi, and J.

D. Embury, ”Electrical Resistivity of Sputtered Cu/Cr Multilayered Thin Films”, J. Applied Physics, Vol. 85, No. 1, January 1999, pp. 302-309.

[21] L. C. Lane, T. C. Nason, G. R. Yang, T. M. Lu, H. Bakhru, “Secondary Ion Mass Spectrometry Study of the Thermal Stability of Cu/ Refractory Metal/ Si

Structures”, J. Appl. Phys., 69 (9), 1 May 1991..

[22] T. Nogami, J. Romero, V. Dubin, D. Brown, E. Adem, "Characterization of the Cu/Barrier Metal Interface for Copper," IEEE, IITC, pp. 98-298.

[23] H. Ono, T. Nakano, T. Ohta, “Diffusion Barrier Effects of Transition Metals for Cu/M/Si Multilayers (M=Cr, Ti, Nb, Mo, Ta, W)”, Appl. Phys. Lett., 64 (12), 21 March 1994.

[24] C.A. Chang, “Thermal Stability of the Cu/ Ta / PtSi Structures”, J. Appl. Phys., 679 (12), 15 June 1990.

[25] E. Kolawa, J.S. Chen, J.S. Reid, P.J. Pokela, M.A. Nicolet, “Tantalum-based Diffusion Barriers in Si/Cu VLSI Metallizaions”, J. Appl. Phys., 70 (3), 1 August 1991.

[26] J.O. Olowolafe, C.J. Mogab, R.B. Gregory, M. Kottke, “Interdiffusions in Cu/

Reactive-ion-sputtered TiN, Cu/ Chemical-vapor-deposited TiN, cu/TaN, and TaN/Cu/TaN Thin-film structures: Low Temperature Diffusion Analyses”, J.

Appl. Phys., 72 (9), 1 November 1992.

[27] S.S. Wong, C. Ryu, H. Lee, A.L.S. Loke, K.W. Kwon, S. Bhattacharya, R. Eaton,

R. Faust, B. Mikkola, J. Mucha, and J. Ormando, “Barrier/Seed Layer Requirements for Copper Interconnects”, IEEE, IITC 98, pp. 107-109.

[28] S. Q. Wang, I. Raaijmakers, B. J. Burrow, S. Redker, K. B. Kim, “Reactively Sputtered TiN as A Diffusion Barrier between Cu and Si”, J. Appl. Phys., 68 (10), 15 November 1990.

[29] Vee S.C. Len, R.E. Hurley, N. McCusker, D.W. McNeill, B.M. Armstrong, H.S.

Gamble, “An investigation into the performance of diffusion barrier materials against copper diffusion using metal-oxide-semiconductor (MOS) capacitor structures”, Solid-State Electronics 43, 1999, pp. 1045-1049.

[30] J.C. Chuang, S.L. Tu, and M.C. Chen, “Sputtered Cr and Reactively Sputtered CrNx Serving as Barrier Layers Against Copper Diffusion”, J, Electrochem. Soc., Vol. 145, No. 12, 1998, pp. 4290-4296.

[31] J.C. Chuang, S.L. Tu, M.C. Chen,”Rapid Thermal Annealed Cr Barrier Against Cu Diffusion”, J. Electrochem. Soc., Vol. 146, No. 7, 1999, pp. 2643-2647.

[32] J.C. Chuang, S.L. Tu, M.C. Chen, ”Sputter-Deposited Mo and Reactively Sputter-Deposited Mo-N films as Barrier Layers Against Cu Diffusion”, Thin Solid Films, Vol.346, 1999, pp. 299-306.

[33] H. Wakabayashi, Y. Saito, K. Takeuchi, T. Mogami, and T. Kunio, “A Novel W/TiNx Metal Gate CMOS Technology using

Nitrogen-Concentration-Controlled TiN_x Film”, IEEE 1999.

[34] S.B. Herner, H.M. Zhang, B. Sun, Y. Tanaka, W. Shi, S.X. Yang, R. Lum, K.A.

Littau, and A. Saleh, “Fluorine Barrier Properties of Bias-Sputtered Tungsten Films”, J. Electrochem. Soc., 147(5), 2000, pp. 1936-1939.

[35] S.Q. Wang, S. Suthar, C. Hoeflich B.J. Burrow, “Diffusion Barrier Properties of TiW between Si and Cu”, J. Appl. Phys. 73 (5), 1 March 1993.

[36] J.C. Chiou, K.C. Juang, and M.C. Chen, “TiW(N) as Diffusion Barriers Between Cu and Si”, J. Electrochem. Soc., Vol. 142, No. 7, July 1997, pp. 2326-2331.

[37] K.K. Lai, A.W. Mark, Thomas P.H.F. Wendling, P. Jian, B. Hathcock,

“Characterization of a PECVD WxN process using N2, H2, and WF6”, Thin Solid Film, 332 (1998), pp. 329-334.

[38] M.T. Wang, Y.C. Lin, J.Y. Lee, C.C. Wang, and M.C. Chen, “Thin-Film

Properties and Barrier Effectiveness of Chemically Vapor Deposited Amorphous Wsi_x Film”, J. Electrochem. Soc., Vol. 145, No. 12, Dec. 1998, pp. 4206-4211.

[39] M.T. Wang, L.J. Chen, and M.C. chen, “Barrier Capabilities of Selective

Chemical Vapor Deposited W Films and WSiN/WSi_x/W Stacked Layers Against Cu Diffusion”, J. Electrochem. Soc., 146 (2), 1999, pp. 728-734.

[40] M.Y. Kwak, D.H. Shin, T.W. Kang, K.N. Kim, “Characteristics of TiN barrier layer against Cu diffusion”, Thin Solid Films, 339 (1999), pp. 290-293.

[41] S.H. Kim, D.S. Chung, K.C. Park, K.B. Kim, S.H. MIN, ”A Comparative Study of Film Properties of Chemical Vapor Deposited TiN Films as Diffusion Barriers for Cu Metallization”, J. Electrochem. Soc., Vol. 146, No. 5, 1999, pp.

1455-1460.

[42] S. Santucci, P. Giuliani, P. Picozzi, A.R. Phani, M.D. Biase, R. Alfonsetti, G.

Moccia, M. Missori, “X-ray reflectivity study on TiN/Ti/Si structures before and after annealing”, Thin Solid Films, 360 (2000), pp. 89-95.

[43] Y.T. Kim,C.H. Jun,D.Y. Kim, ”Barrier Properties of TiN/TiSi2 Bilayers Formed Two-Step Rapid Thermal Conversion Process for Cu Diffusion Barrier”, Thin Solid Films, 347 (1999), pp. 214-219.

[44] S.D. Kim, S.G. Jin, M.R. Hong, and C.T. Kim, “Rapid Thermal Process for Enhancement of Collimated Titanium Nitride Barriers”, J. Electrochem. Soc.,

Vol. 144, No. 2, 1997, pp. 664-669.

[45] J.S. Chen, and J.L. Wang, “Diffusion Barrier Properties of Sputtered TiB2

Between Cu and Si”, J. Electrochem. Soc., Vol. 147 (5), 2000, pp. 1940-1944.

[46] J.Y. Yun, M.Y. Park, and S.W. Rhee, ”Comparison of Tetrakis (dimethylamido) titanium and Tetrakis (diethylamido) titanium as Precursors for Metallorganic Chemmical Vapor Deposition of Titanium Nitride”, J. Electrochem. Soc., Vol.

146, No. 5, 1999, pp. 1804-1808.

[47] H.J. Lee, and R. Sinclar, ”A Study of the Mechanism of Titanium Nitride Diffusion Barrier”, Journal of Applied Physical, Vol. 144, No. 3, 1999, pp.

3096-3103.

[48] K. Holloway and P. Fryer, “Tantalum as a diffusion barrier between copper and silicon”, Appl. Phys. Lett., 57 (17), 1990, pp. 1736-1738.

[49] E. Kolawam, P.J. Pokela, J.S. Chen and M.A. Nicolet, “Amorphous Ta-Si-N Diffusion Barriers in Si/Al and Si/Cu Metalizations”, Applied Surface Science, 53, 1991, pp. 373-376.

[50] M.S. Angyal, Y.S. Diamand, J.S. Reid, and M.A. Nicolet, “Performance of tantalum-silicon-nitride diffusion barriers between copper and silicon dioxide”, Appl. Phys. Lett., 67 (15), 1995, pp. 2152-2154.

[51] E. Ivanov, “Tantalum Silicide Sputtering Target Material for Amorphous Ta-Si-N Diffusion Barrier for Cu Metallization”, IEEE, IITC 98, pp. 256-258.

[52] J.S. Reid, E. Kolawa, R.P. Ruiz and M.A. Nicolet, “Evaluation of amorphous (Mo, Ta, W)-Si-N diffusion barriers for Cu metallizations”, Thin Solid Films, 236 (1993), pp. 319-324.

[53] M.A.Nicolet, ”Ternary Amorphous Metallic Thin Films as Diffusion Barriers for Cu Metallization”, Applied Surface Science, 91 (1995), pp. 269-276.

[54] Y.J. Lee, B.S. Suh, M.S. Kwon, and C.O. Park, “Barrier Properties and Failure Mechanism of Ta-Si-N Thin Films for Cu Interconnection”, J. Appl. Phys, Vol.

85, No. 3, 1999, pp. 1927-1934.

[55] C. Lee and Y.H. Shin, “Ta-Si-N as a diffusion barrier between Cu and Si”, Materials Chemistry and Physics, 57 (1998), pp. 17-22.

[56] E. Ivanov, “Evaluation of tantalum silicide sputtering target materials for amorphous Ta-Si-N diffusion barrier for Cu metallization”, Thin Solid Films, 332 (1998), pp. 325-328.

[57] J.S. Reid, R.Y. Liu, P.M. Smith, R.P. Ruiz, M.A. Nicolet, “W-B-N diffusion barriers for Si/Cu metallizations”, Thin Solid Films, 262 (1995), pp. 218-223.

[58] D.J. Kim, Y.T. Kim, and J.W. Park, “New method to prepare W-B⁺-N ternary barrier to Cu diffusion by implanting BF2+

ions into W-N thin film”, J. Vac. Sci.

Technol., B 17(4), 1999, pp. 1598-1601.

[59] J.O. Olowolafe, I. Rau, K.M. Unruh, C.P. Swann, Z. Jawad, and T. Alford, “The Effect of Ta to Si Ratio on Magnetron Sputtered Ta-Si-N Thin Films”, J.

Electronic Materials, Vol. 28, No. 12, 1999, pp. 1399-1402.

[60] T. Takewaki, H. Yamada, T. Ohmi, T. Shibata, and T. Nitta, in Proc. Int. Conf.

Adv. Microelectronic Devices and Processing, Tohuku University, Sendai, Japan, March 3, 1994, p. 489.

[61] E. Kolawam, P.J. Pokela, J.S. Reid, J.S. Chen, R.P. Ruiz, M.A. Nicolet,

“Sputtered Ta-Si-N Diffusion Barriers in Cu Metallization for Si”, IEEE Electron Device Letters, Vol. 12, No. 6, June 1991.

[62] X. Sun, J.S. Reid, E. Kolawa, and M.A. Nicolet, ”Reactively sputtered Ti-Si-N films as Diffusion barriers for Al and Cu metallizations on Si”, J. Appl. Phys., 81 (2), 1997, pp. 664-671.

[63] J.T. No, J.H. O, C. Lee, “Evaluation of Ti-Si-N as a diffusion barrier between copper and silicon”, Materials Chemistry and Physics, 63 (2000), pp. 44-49.

[64] 蕭宏(Hong Xiao)著，半導體製程技術導論，羅正忠、張鼎張譯，台灣培生

教育，台北市，二版，中華民國九十一年一月。

[65] 楊恆傑、鍾鴻欽、劉全璞，「銅製程之擴散阻障層材料的發展與挑戰」，工

業材料，177 期，民國九十年九月。

[66] 吳文發，「銅導線之導體擴散阻障材料」，電子月刊，第八卷第四期，112-120

頁，民國九十一年四月。

[67] 張鼎張，胡榮治，「金屬化學氣相沉積在積體電路技術的發展」，真空科技，

第十二卷第二期，27-33 頁，民國八十八年七月。

[68] 盧火鐵，微電子材料與製程，初版，324 頁，新竹市，中國材料科學學會，

民國八十九年十一月。

[69] Keng-Liang Ou, Ming-Sun Hsu, Ray-Quen Hsu, Ming-Hong Lin, “Comparative study of polycrystalline Ti, amorphous Ti, and multiamorphous Ti as a barrier film for Cu interconnection”, J. Vac. Sci. Technol., B 23(1), 2005, pp. 229-235.

在文檔中 氮化鋁鈦擴散阻障層在銅金屬化製程中熱穩定性及特性之研究 (頁 55-74)