Spectroscopic Ellipsometry Investigations of Amorphous Diamond Films Deposited with Filtered Arc
ZHU Jia-qi1, HAN Jie-cai1, TAO Yan-chun2, JIANG Chun-zhu1
1. Center for Composite Materials, Harbin Institute of Technology, Harbin 150080, China 2. Key Lab for Supermolecular Structure and Materials of Ministry of Education, Jilin University, Changchun 130012, China
Abstract：In order to investigate thoroughly the optical properties of amorphous diamond (α-D) films deposited by the filtered vacuum arc technology, the optical constants of the films were measured by spectroscopic ellipsometry. Moreover, the dispersion relations of the optical constants, and the correlations among refractive index, extinction coefficient, optical gap and the substrate bias were also analyzed. It has been shown that the refractive index of α-D films is higher than that of diamond crystal, and the absorption edge corresponding to the interband transformation can be described with the parabolic line shape. With increasing the wavelength, the extinction coefficient gradually declines and approaches nearly to zero in the infrared band. In addition, the adjustable amplitudes of the optical constants owing to the changing bias also reduce strikingly with the extension of the wavelength. With raising the bias, the refractive index and the optical gap firstly augment, then minish, and there is a maximal value when the substrate bias is -80 V. However, the extinction coefficient firstly minishes, then augments, and there is a minimal value when the bias is -80 V.
[1] Robterson J. Materials Science and Engineering R, Reports: A Review Journal, 2002, 37(4-6): 129. [2] HUANG Wei-dong，ZHAN Ru-juan(黄卫东，詹如娟). Spectroscopy and Spectral Analysis(光谱学与光谱分析)，2003，23(3)：512. [3] HU Ying, XING Xiu-san(胡 颖, 邢修三). Spectroscopy and Spectral Analysis(光谱学与光谱分析)，2001，21(5)：588. [4] Shi Xu, Tay B K, Tan H S, et al. J. Appl. Phys.，1996, 79: 7234. [5] McGahan W A, Makovicka T, Hale J, et al. Surface and Coatings Technology, 1993, 62: 707. [6] Lifshitz Y, Lempert G D, Grossman E, et al. Diamond and Related Materials, 1997, 6: 687. [7] Woollam J A. Ellipsometry, Variable Angle Spectroscopic. Webster J G. Editor, Wiley Encyclopedia of Electrical and Electronics Enigineering. A Wiley-Interscience Publication, 2000. 109. [8] ZHU Jiaqi, HAN Jiecai, MENG Songhe, et al. J. Mater. Sci. Technol., 2003, 19(Suppl.1): 109. [9] Tropf W J, Harris T J, Thomas M E. Optical Materials: Visible and Infrared. Edited by Waynant R W and Ediger M N. Electro-Optics Handbook (2nd Edition). Columbus: McGraw-Hill Press, 2000. 11, 29. [10] Zhang X W, Cheung W Y, Ke N, et al. J. Appl. Phys., 2002, 92(3): 1242. [11] Xiong Fulin, Wang Y Y, Chang R P H. Physical Review B, 1993, 48(11): 8016. [12] Canillas A, Polo M C, Andujar J L, et al. Diamond and Related Materials, 2001, 10: 1132. [13] Tay B K, Shi X, Cheah L K, et al. Thin Solid Films, 1997, 308-309: 268. [14] Chen Z Y, Zhao J P. J. Appl. Phys., 2000, 87(9): 4268. [15] Gilkes K W R, Gaskell P H, Yuan J. Journal of Non-Crystalline Solids, 1993, 164-166: 1107. [16] Jungnickel G, Khler Th, Frauenheim Th, et al. Diamond and Related Materials, 1996, 5(2): 175. [17] Souza D R de, Soares L L, Cescato L, et al. Microelectronics Journal, 2000, 31: 251. [18] Smith F W. J. Appl. Phys., 1984, 55(3): 764. [19] Godet C, Conway N M J, Bourée J E, et al. J. Appl. Phys., 2002, 91(7): 4154. [20] Forouhi A R, Bloomer I. Physical Review B, 1986, 36(10): 7018. [21] Lossy R, Pappas D L, Roy R A, et al. J. Appl. Phys., 1995, 77(9): 4750. [22] Lettington A H. Carbon, 1998, 36(5-6): 555. [23] Veerasamy V S, Amaratunga G A J, Milne W I, et al. Diamond and Related Materials, 1993, 2(5-7): 782. [24] Polo M C, Andújar J L, Hart A, et al. Diamond and Related Materials, 2000, 9: 663. [25] LIU En-ke, ZHU Bing-sheng, LUO Jin-sheng, et al(刘恩科，朱秉升，罗晋生, 等). Semiconductor Physics. the 4<sup>th</sup> Edition(半导体物理学, 第4版). Beijing: Defence Industry Press(北京：国防工业出版社)，2002. 340. [26] Teo K B K, Ferrari A C, Fanchini G, et al. Diamond and Related Materials, 2002, 11: 1086. [27] Drabold D A, Fedders P A, Grumbach M P. Phys. Rev. B, 1996, 54(8): 5480. [28] Fusco G, Tagliaferro A, Milne W I, et al. Diamond and Related Materials, 1997, 6(5-7): 783.
