摘要

薄膜建構單元與薄膜結構之間的關係，一直是許多學者與工程師深感興趣的問題。本研究藉由分子動力學程式DL-POLY，採用Sutton-Chen位能函數描述原子之間交互作用來模擬金/鉑叢聚沉積於金/鉑基材的過程。以瞭解在帶電叢聚模型假設下，金叢聚與鉑叢聚沉積在基材上沉積之結構變化。

首先針對影響叢聚結構之因素進行研究。由不同尺寸叢聚的均方根位移(MSD)結果顯示，叢聚尺寸越大其結構越穩定。由不同溫度叢聚的徑向分佈函數(RDF)結果顯示，叢聚溫度越低，其結構越穩定。前者是由於尺寸大的叢聚內部原子受到較多原子間之束縛而不容易移動，後者是由於低溫時原子動能較小。不論由MSD或RDF均顯示鉑叢聚比金叢聚穩定。

接著進行同材質及異材質之金/鉑叢聚沉積模擬，包括「金叢聚沉積於金基材」、「鉑叢聚沉積於鉑基材」、「金叢聚沉積於鉑基材」和「鉑叢聚沉積於金基材」四種情況，並觀察叢聚尺寸改變造成之影響。結果發現尺寸較大之叢聚，其結構調整時間較長。金叢聚沉積時結構調整所需之時間比鉑叢聚長。且此調整結構所需時間與基材無關。金叢聚沉積造成之接觸角小於90度，鉑叢聚沉積造成之接觸角大於90度。接觸角與基材之材質及叢聚之尺寸關係不大。結構調整所需之時間和接觸角的大小，皆與叢聚原子間的作用力有關。原子間作用力較大之鉑原子叢聚，其結構調整時間較短而形成之接觸角較大。原子間作用力較小之金原子叢聚，其結構調整時間較長而形成之接觸角較小。

本研究結果顯示，以溫度1000K之金/鉑叢聚沉積於溫度800K之金/鉑基材，在沉積過程造成的叢聚之結構改變，皆呈現以叢聚材料為主要影響因素。本研究之分子動力學模擬結果可作為金/鉑薄膜沉積機制之參考。

[1] A. A. Schmidt, H. Eggers, K. Herwig, R. Anton,“Comparative investigation of the nucleation and growth of fcc-metal particle (Rh, Ir, Ni, Pd, Cu, Ag, Au) on amorphous carbon and SiO2 substrate during vapor deposition at elevated temperatures,” Surface Science, 349, 301-316 (1996).
[2] B. J. Alder and T. E. Wainwright,“Decay of the velocity autocorrelation function,” Phys. Rev. A, 1, 18 (1970).
[3] B. J. Alder and T. E. Wainwright,“Phase transition for a hard sphere system,”J. Chem. Phys., 27, 1208 (1957).
[4] B. J. Alder and T. E. Wainwright,“Phase transition in elastic disks,”Phys. Rev., 127, 359 (1962).
[5] B. J. Alder and T. E. Wainwright,“Studies in molecular dynamics VIII. The transport coefficients for a hard-sphere fluid,”J. Chem. Phys., 53, 3813 (1970).
[6] B. J. Alder and T. E. Wainwright,“Velocity autocorrelation for hard spheres,”Phys. Rev. Lett., 18, 088 (1967).
[7] B. J. Lee, M. I. Baskes, H. Kim, Y. K. Cho,“Second nearest-neighbor modified embedded atom method potentials for bcc transition metals,”Phys. Rev. B, 64, 184102 (2001).
[8] C. R. Metz,“Theory and problem of Physical Chemistry,” McGraw-Hill, (1989).
[9] D. Frenkel and B. Smit,“Understanding Molecular Simulation：From Algorithms to Applications,”Academic Press Inc. (London) Ltd (2001).
[10] D. C. Rappaport,“The Art of Molecular Dynamics Simulation,”Cambridge， 2nd Ed. ( 2004).
[11] D. Conrad and K. Scheerschmidt,“Empirical bond-order potential for semiconductors,”Phys. Rev. B, Vol. 58, 8 (1998).
[12] D. J. Oh and R. A. Johnson,“Simple embedded atom method model for fcc and hcp metals,”J.Mater. Res., Vol. 3, No.3, 471 (1988).
[13] M. W. Finnis, J. E. Sinclair,“A Simple Empirical N-Body Potential For Transition Metals,”Philosophical Magazine A, Vol. 50, 45-55, (1984).
[14] G.. H. Gilmer, H. Huang,“Christopher Roland，Thin film deposition：fundamentals and modeling,”Computational Materials Science, 12, 354-380 (1998).
[15] H. Zhang, Z. N. Xia,“Molecular dynamics simulation of cluster beam Al deposition on Si(100) substrate,”Nuclear Instruments and Methods in Physics Research B, 160 , 372-376 (2000).
[16] J. J. Duderstadt, L. J. Hamilton,“Nuclear Reactor Analysis,”Hohn Wiely & Sons, Inc. (1976)
[17] J. E. Lennard-Jones,“The Determination of Molecular Fields I. From the Variation of Viscosity of Gas with Temperature,”Proc. Roy. Soc. (lond.), 106A, 441, 1924；“The Determination of Molecular Fields II. rom the Variation of Viscosity of Gas with Temperature,”Proc. Roy. Soc. (lond.), 106A, 463 (1924).
[18] J. K. Johnson, J. A. Zollweg and K. E. Gubbins,“The Lennard-Jones equation of stat revisited,”Molecular Physics, Vol. 78, No. 3 591-618 (1993).
[19] J. M. Haile,“Molecular Dynamics Simulation：Elementary Methods,”John Wiely& Sons, Inc., USA (1992).
[20] J. Tersoff,“New Empirical Model for the Structural Properties of Sillicon,”Phys. Rev. Lett., 56, 632 (1986).
[21] J. L. Rodr□guez-L□pez, J. M. Montejano-Carrizales, M, Jos□-Yacam□n,“Molecular dynamics study of bimetallic nanoparticles： the case of AuxCuy alloy cluster,”Applied Surface Science, 219, 56-63 (2003).
[22] J. Emsley,“The Elements,”Clarendon Press, Oxford, 3rd Ed. (1998).
[23] K. Shintani, Y. Taniguchi, and S. Kameoka,“Molecular-dynamics analysis of morphological evolution of softly deposited Au nanoclusters,”J. Appl. Phys., Vol. 95, NO. 12, 14, June 2004.
[24] K. Tsujimoto, S. Mitani, T. Teraji, T. Ito,“Fabraction of non-sized platinum particle self-assembled on and in CVD diamond films,”Applied Surface Science, 237, 488-493 (2004).
[25] L. Verlet,“Computer 'Experiments' on Classical Fuilds II, Equilibrium Correlation Function,”Phys. Rev., Vol. 165, pp. 201~214（1968）.
[26] M. Hwang, J. H. Hanh, D. Y. Yoon,“Charged cluster model in the low pressure synthesis of diamond,”Journal of Crystal Growth, 162 , 55-68 (1996).
[27] M. S. Daw, M. I. Baskes,“Embedded-atom method： Derivation and application to impurities, surfaces, and other defects in metals,”Phys. Rev. B, 29 , 6443 (1984).
[28] M. P. Allen，D. J. Tidesley,“Computer Simulation of Liquids,”Clarendon Press, Oxford (1996).
[29] M. C. Barnes, In-D. Jeon, D.Y. Kim, N. M. Hwang,“Generation of charged cluster during thermal evaporation of gold,”Journal of Crystal Growth, 242 , 455-462 (2002).
[30] M. Welsb, M. K. Dalbeimer, L. Kaufman,“Running Linux, 3/e,”O'Relly & Associates INC. (1999).
[31] Microsoft,“UNIX Application Migration Guide,”Microsoft Press (2003).
[32] M. Ohring,“Materials Science of Thin Films ：Deposition and structure 2nd,”San Diego, CA :Academic Press,c (2002).
[33] N. M. Hwang, J. H, Hahn,D. Y. Yoon,“Chemical potential of carbon in the low pressure synthesis of diamond,”Journal of Crystal Growth, 160 , 87-97(1996).
[34] N. M. Hwang, J. H. Hahn, D. Y. Yoon,“Charged cluster model in the low pressure synthesis of diamond,”Journal of Crystal Growth, 162, 55-68 (1996).
[35] N. M. Hwang,“Deposition and simulation etching of Si in the Chemical vapor deposition (CVD) process：approach by the charged cluster model,”Journal of Crystal Growth, 205 , 59-63(1999).
[36] P. M. Agrawl, B. M. Rice, D. L. Thompson,“Predicting trends in rate parameters for self-diffusion on FCC metal surfaces,”Surface Science, 515 , 21-35(2002).
[37] Ph. Buffat and J.P. Borel,“Size effect on the melting temperature of gold particles,”Phys. Rev. A, 13, 2287–2298 (1976).
[38] R. E. Reed-Hill and R. Abbaschian,“Physical Metallurgy Principles,3rd ed. ,”PWS-KENT (1992).
[39] R. W. Cahn and P. Hassen eds.,“Physical Metallurgy,3rd ed. ”,Elsevier (1983).
[40] S. Ozgen, E. Duruk,“Molecular dynamics simulation of solidification kinetics of aluminum using Sutton-Chen version of EAM,”Materials Letters, 58 ,1071-1075 (2004).
[41] S. Ozawa, Y. Sasajima, D. W. Heermann,“Monte Carlo Simulation of film growth,”Thin Soild Films, 272, 172-183 (1996).
[42] S .C. Lee, B. D. Yu, D.Y. Kim, N. M. Hwang,“Effects of cluster sizer and substrate temperature on the homopitaxial deposition of Au cluster,”Journal of Crystal Growth, 242 , 463-470(2002).
[43] S. C. Lee, N. M. Hwang, B. D. Yu, D.Y. Kim,“Molecular dynamics simulation on the deposition behavior of nanometer-sized Au clusters on a Au(001) surface,”Journal of Crystal Growth, 223 , 311-320 (2001).
[44] S. Maruyama,“Molecular Dynamics Method for Microscale Heat Transfer,”Begell house (2002).
[45] S. B. Lippman，J. Lajoie,“C++ Primer 3rd,” Addison Wesley (1998).
[46] A. P. Sutton, and J. Chen,“Long-rnage Finnis-Sinclair potential,”Philos. Mag. Lett., 61, 139 (1990).
[47] T. □ağın,“Thermai and mechanical properties of some fcc transition metals,”Phys. Rev. B, Vol. 59(5) (1991).
[48] T. R. Forest, W. Smith,“DL_POLY_2 reference manual,”Version 2.13 (2001).
[49] W. C. Swope, H. C. Andersen，P. H. Berens and K. R. Wilson,“Computer simulation method for the calculation of equilbritum of constants for the formation of phyical clusters of molecules：application to small water cluster,”J. Chem. Phys., 76, p637~649(1982)
[50] W. Sarlet,“Exact invariants for time-dependent Hamiltonian system with one degree-of-freedom,”J. Phys. A: Math. Gen., Vol. 11, No 5, (1978).
[51] W. A. Tiller,“The science of crystalline：microscopic interfacial phenomena,”Cambridge University Press (1991).
[52] Y. Shibnta and S. Maruyama,“Molecular Dynamics Simulation of Growth Process,”Chem. Phys. Lett., 382, 381 (2003).
[53] 林惠娟，“計算奈米科技簡介，”材料會訊 電腦模擬專輯 ，2000[民91]年12月。
[54] 林慧祈，“細微粒子在化學蒸氣沉積反應器之成長，”國立清華大學，化學工程研究所碩士論文，1996[民85]年。
[55] 洪仕偉，“以分子動力學模擬自組裝單分子膜之表面特性，”國立清華大學，工程與系統科學系碩士論文，2005[民94]年。
[56] 馬遠榮，“奈米科技，”周商出版，2005[民94]年5月七刷。
[57] 張金泉，“奈米模擬技術---動力蒙地卡羅方法於薄膜沉積模擬之應用，”工業雜誌2001[民92]年12月204期•p159~165。
[58] 彭國倫，“Fortran 95 程式設計，”□峰資訊，2001 [民90] ，初版。
[59] 劉國雄、林樹均、鄭晃忠、葉鈞蔚，“工程材料學，”全華科技圖書，1995[民84再版]。
[60] 徐義人，“工程機率統計學，”國立編譯館主編，華泰文化事業印行，2001[民90]，修訂版。
[61] W. F. Smith著/李春穎、許煙明、陳忠仁 譯，“材料科學與工程，”高立圖書，1994[民83]。
[62] http://www.kernel.org
[63] http://web.mit.edu/8.333/www/solutions/sol1.pdf