摘 要
具有多孔結構 (porous structure) 的低介電係數材料SiOC (Black Diamond, BD)，可以降低介電常數(dielectric constant) k，故廣泛的使用在深次90奈米技術上。然而吾人經由掃描式電子顯微鏡 (SEM) 所獲得之照片顯示因其具有多孔結構，會使其薄膜硬度降低，在經過化學機械研磨 (CMP) 後，容易在薄膜上造成深度刮傷。這些刮傷在後續製程會導致銅導線橋接，並且造成電路嚴重的故障。本論文針對介電常數 k、硬度 (hardness)，與緻密度 (porosity) 之間的關係，作深入且詳細的研究。此外，吾人使用電子束來測試及研究不同參數條件樣品的機械特性。

Abstract
The low-k dielectric SiOC (Black Diamond, BD) widely used in deep sub-90 nm technology has a porous structure to lower the dielectric constant k. However, in this study we have found with SEM (scanning electronic microscope) that porous structure also degrades hardness of BD dielectric and causes a deep scratch after chemical mechanical polishing (CMP). The scratch then induces copper interconnect bridges to result a serious malfunction of circuit. Furthermore, the relationships among the k value, hardness and porosity were studied in detail. Additionally, the electron beam was used to test mechanical properties of the samples with various preparing conditions of BD films.

Reference

[1] Sailesh M. Merchant, Kang Seung H., Mahesh Sanganeria, Bart van Schravendijk, and Tom Mountsier, “ Copper Interconnects for Semiconductor Devices”, JOM, pp. 43-48, June 2001.
[2] Tohru Hara, Fumiaki Togoh, Toshaki Kurosu, Keiichi Sakamoto, Yoshimi Shioya, Tomomi Ishimaru, and Toshiro K. Doy, “Mechanism of Mechanical and Chemical Polishing in Low Dielectric Constant Plasma-Enhanced Chemical Vapor Deposition SiOC Layer from Hexamethyldisloxane”, Electrochemical and Solid-State Letters, 4 G65-G67, 2001.
[3] Shiu-Ko JangJiana,b, Chuan-Pu Liua, Ying-Lang Wangb,*, Weng-Sing Hwanga, Wei-Tsu Tsenga, “Thermal stability and bonding configuration of fluorine-modified low-k SiOC:H composite films”, Thin Solid Films 469–470 (2004) 460–465
[4] H. K. Kim and F. G. Shi, “Thickness Dependent Dielectric Strength of a Low-permittivity Dielectric Film”, IEEE Transactions on Dielectrics and Electrical Insulation Val. 8 No. 2, pp. 248-252, April 2001,
[5] Christopher L. Borst, Vincent Korthuis, Gregory B. Shinn, J.D. Luttmer, Ronald J.Gutmann, William N. Gill, “Chemical-mechanical polishing of SiOC organosilicate glasses: the effect of film carbon content”, Thin Solid Film 385 pp.281-292, 2001.
[6] Kloster G., Scherban T., Xu G., Blaine J., Sun B., Zhou Y., “Porosity Effects on Low-k Dielectric Film Strength and Interfacial Adhesion”, IEEE pp. 242-244, 2002.
[7] Brian R. Smith, Cristina H. Amon, ”Effect of sub-sontinuum energy transport on effective thermal conductivity in nanoporous silica (aerogel)”, Proceedings of IMECE’03, Washington, D.C., USA, Nov 15-21,2003, pp. 1-9.
[8] Wang, David H.; Chiao, Stephen; Afnan, Mohammed; Yih, Paul; Rehayem, Michel, “Stress-free polishing advances copper integration with ultralow-k dielectrics.” Solid State Technology, Vol. 44 Issue 10, Oct., 2001, pp.101-104.
[9]Goldstein, Joseph, “Scanning electron microscopy and X-ray microanalysis-/a text for biologists, materials scientists, and geologists”, Plenum Press, New York,c1981.
[10]Michael Quirk, Julian Serda., “Semiconductor manufacturing technology”, Prentice Hall, Upper Saddle River, NJ, c2001.pp.77-78
[11]Solid State Measurements, Inc. June 2001 r1.1 C-V Measurement of Low-k Dielectrics Application Brief
[12]. M. D’Elia, Capacitance-Voltage Measurements in a Manufacturing Environment. Sematech, copyright 1992.
[13] D. K. Schroder, Semiconductor Material and Device Characterization, ch. 6. John Wiley & Sons, Inc., New York, 1990.
[14]Hong Xiao,“Introduction to semiconductor manufacturing technology”, Prentice Hall, Upper Saddle River, NJ, c2001.pp.515-516
[15 ] Nanoindenter XP by MTS Systems Corporation, 14000 Technology Drive, Eden Prairie, MN 55344-2290, USA, http://www.mts.com/