후속 열처리에 따른 Cu 박막과 ALD Ru 확산방지층의 계면접착에너지 평가
Effect of Post-annealing on the Interfacial adhesion Energy of Cu thin Film and ALD Ru Diffusion Barrier Layer
0
조회
0
다운로드
1
인용
0
참고문헌
키워드
초록
차세대 초미세 Cu 배선 적용을 위한 원자층증착법(atomic layer deposition, ALD)을 이용하여 증착된 Ru확산방지층과 Cu 박막 사이의 계면 신뢰성을 평가하기 위해, Ru 공정온도 및 200oC 후속 열처리 시간에 따라 4점굽힘시험으로 정량적인 계면접착에너지를 평가하였고, 박리계면을 분석하였다. 225, 270, 310oC 세 가지 ALD Ru 공정온도에 따른계면접착에너지는 각각 8.55, 9.37, 8.96 J/m2로 유사한 값을 보였는데, 이는 증착온도 변화에 따라 Ru 결정립 크기 등 미세조직 및 비저항의 차이가 적어서, 계면 특성도 거의 차이가 없는 것으로 판단된다. 225oC의 공정온도에서 증착된 Ru 박막의 계면접착에너지는 200oC 후속 열처리시 250시간까지는 7.59 J/m2 이상으로 유지되었으나, 500시간 후에는 1.40 J/ m2로 급격히 감소하였다. 박리계면에 대한 X-선 광전자 분광기 분석 결과, 500시간 후 Cu 계면 산화로 인하여 계면접착에너지가 감소한 것으로 확인되었다. 따라서 ALD Ru 박막은 계면신뢰성이 양호한 차세대 Cu 배선용 확산방지층 후보가 된다고 판단된다.
Abstract
The effects of Ru deposition temperature and post-annealing conditions on the interfacial adhesion energies of atomic layer deposited (ALD) Ru diffusion barrier layer and Cu thin films for the advanced Cu interconnects applications were systematically investigated. The initial interfacial adhesion energies were 8.55, 9.37, 8.96 J/m2 for the sample deposited at 225, 270, and 310oC, respectively, which are closely related to the similar microstructures and resistivities of Ru films for ALD Ru deposition temperature variations. And the interfacial adhesion energies showed the relatively stable high values over 7.59 J/m2 until 250h during post-annealing at 200oC, while dramatically decreased to 1.40 J/m2 after 500 h. The X-ray photoelectron spectroscopy Cu 2p peak separation analysis showed that there exists good correlation between the interfacial adhesion energy and the interfacial CuO formation. Therefore, ALD Ru seems to be a promising diffusion barrier candidate with reliable interfacial reliability for advanced Cu interconnects.
참고문헌 (29)
- M. T. Bohr, "Interconnect scaling - the real limiter to high performance ULSI", Proc. Proceedings of International Electron Devices Meeting (1995), IEEE
- 김명준, "반도체 소자용 구리 배선 형성을 위한 전해 도금", Korean Chemical Engineering Research(HWAHAK KONGHAK), 52(1), pp.26~39 (2014), 한국화학공학회[DOI]
- P. C. Andricacos, "Damascene copper electroplating for chip interconnections", IBM J. Res. Dev, 42(5), pp.567~ (1998)
- P. M. Vereecken, "The chemistry of additives in damascene copper plating", IBM J. Res. Dev, 49(1), pp.3~ (2005)
- 권오중, "구리 및 은 금속 배선을 위한 전기화학적 공정", Korean Chemical Engineering Research(HWAHAK KONGHAK), 47(2), pp.141~149 (2009), 한국화학공학회
- 김명준, "(The)influences of pulse and pulse-reverse electrodeposition on the properties of Cu thin films and superfilling for the fabrication of Cu interconnection", 박사, 화학생물공학부, pp.2013
- J. W. Pyun, "Effect of barrier process on electromigration reliability of Cu", porous low-k interconnects, 2006, pp.100(2), 023532~
- H. P. Feng, "Mechanism for Cu void defect on various electroplated film conditions", Thin Solid Films, 498(1-2), pp.56~ (2006)
- D. Gilkes, "Effect of copper seed aging on electroplating-induced defects in copper interconnects", J. Electron. Mater, 31(10), pp.1047~ (2002)
- S. M. Rossnagel, "Time development of microstructure and resistivity for very thin Cu films", J. Vac. Sci. Technol, 20(6), pp.1911~ (2002)
- T. E. Hong, "Atomic layer deposition of Ru thin film using N2", H2 plasma as a reactant, 2012, pp.520(19), 6100~
- H. Kim, "Applications of atomic layer deposition to nanofabrication and emerging nanodevices", Thin Solid Films, 517(8), pp.2563~ (2009)
- M. W. Lane, "Liner materials for direct electrodeposition of Cu", Appl. Phys. Lett, 83(12), pp.2330~ (2003)
- M. Abe, "Highly-oriented PVD ruthenium liner for low-resistance direct-plated Cu interconnects", Proc. 2007 IEEE International Interconnect Technology Conference (IITC) (2007)
- S. Ogawa, "Amorphous Ru", polycrystalline Ru highly reliable stacked layer barrier technology, 2008, ~[DOI]
- C. C. Yang, "Physical, Electrical, and Reliability Characterization of Ru for Cu Interconnects", Proc. 2006 International Interconnect Technology Conference (IITC) (2006), IEEE
- R. Chan, "Diffusion studies of copper on ruthenium thin film: A plateable copper diffusion barrier", Electrochem. Solid-State Lett, 7(8), pp.G154~ (2004)
- H. Kim, "Cu wettability and diffusion barrier property of Ru thin film for Cu metallization", J. Electrochem. Soc, 152(8), pp.G594~ (2005)
- M. W. Lane, "Relationship between interfacial adhesion and electromigration in Cu metallization", J. Appl. Phys, 93(3), pp.1417~ (2003)
- R. H. Dauskardt, "Adhesion and debonding of multi-layer thin film structures", Eng. Fract. Mech, 6(1), pp.141~ (1998)
- 김재원, "4-point bending test system을 이용한 Cu-Cu 열 압착 접합 특성 평가", 마이크로전자 및 패키징학회지, 18(4), pp.11~18 (2011), 한국마이크로전자및패키징학회
- P. G. Charalambides, "A test specimen for determining the fracture resistance of bimaterial interfaces", J. Appl. Mech, 56(1), pp.77~ (1989)
- T. Scherban. B. Sun, "Interfacial adhesion of copper-low k interconnects", Proc. 2001 International Interconnect Technology Conference (IITC) (2001)
- J. H. Jung, "Atomic Layer Deposition of Ru Thin Films Using a New Beta-Diketonate Ru Precursor and NH3 Plasma as a Reactant", J. Nanosci. Nanotechnol, 15(11), pp.8472~ (2015)
- H. J. Lee, "Atomic layer deposited self-forming Ru-Mn diffusion barrier for seedless Cu interconnects", J. Alloys Compd, 686(25), pp.1025~ (2016)
- T. K. Eom, "Formation of Nano-Crystalline Ru-Based Ternary Thin Films by Plasma-Enhanced Atomic Layer Deposition", Electrochem. Solid-State Lett, 14(1), pp.D10~ (2011)
- M. W. Lane, "Environmental effects on interfacial adhesion", Microelectron. Reliab, 41(9-10), pp.1615~ (2001)
- M. S. Jeong, "Effects of post-annealing", temperature, Proc. 15th International Conference on Electronic Materials and Packaging and 12th International Symposium on Microelectronics and Packaging (EMAP, pp.ISMP), 2013
- 정민수, "습식표면처리 및 열 사이클에 따른 Cu", SiNx 계면접착에너지 평가 및 분석, 2014, pp.21(1), 45~50[DOI]