Damascene copper

The acceptance of chemical mechanical planarization (CMP) as a manufacturable process for state-of-the-art interconnect technology has made it possible to rely on CMP technology for numerous semiconductor manufacturing process applications. These applications include shallow trench isolation (STI), deep trench capacitors, local tungsten interconnects, inter-level-dielectric (ILD) planarization, and copper damascene. In this chapter. 

Wrschka P, Hernandez J, Oehrlein G. Chemical mechanical planarization of copper damascene structures. J Electrochem Soc 2000 147(2) 706-712. 

Kondo S, Sakuma N, Homma Y, Goto Y, Ohashi Ni, Yamaguchi H, Owada N. Abrasive-free polishing for copper damascene interconnection. J Electrochem Soc 2000 147(10) 3907-3913. 

FIGURE 16.21 Image of galvanic corrosion on copper damascene line (from Ref. 59). 

FIGURE 17.24 Schematic illustration of some integration options to make a copper damascene structure. 

This wealth of copper CMP data has not narrowed the focus of developing an abrasive particle-copper interaction model, but actually expanded it. Copper can be polished with various abrasives, in the presence of various suppressants and with a wide range of oxidants over a wide pH range. Because of the very rigorous demands of copper damascene CMP, and the incomplete current understanding, the research effort focussed on copper is still growing. 

To this point we have discussed recent model extensions in the context of oxide CMP. As illustrated schematically in Fig. 1, dishing and erosion concerns in copper damascene processing also... 

K. (2004) Role of Additives for Copper Damascene Electrodeposition Experimental Study on Inhibition and Acceleration Effects. J. Electrochem. Soc., 151, C250-C255. 

Figure 1.12 Copper Damascene process (cross-sectional view). 

J. -Q Lu, et al.. A wafer-scale 3-D IC technology platform using dielectric bonding glues and copper damascene patterned inter-wafer interconnects. In Proc. IntT Interconnect Technology Conf., 2002, pp. 78 - 80. 

Figure 9.5 Comparison of conventional copper damascene CMP with the abrasive-free process [7,8].

Helneder H, Korner H, Mitchell A, Schwerd M, Seidel U. Comparison of copper damascene and aluminum RIE metallization in BICMOS technology. Microelectron. Eng. 

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