Chemical mechanical planarization processing mechanism

This review addresses the issues of the chemical and physical processes whereby inorganic anions and cations are selectively retained by or passed through cell membranes. The channel and carrier mechanisms of membranes permeation are treated by means of model systems. The models are the planar lipid bilayer for the cell membrane, Gramicidin for the channel mechanism, and Valinomycin for the carrier mechanism. 

Zhang, R, Busnaina, A. A., Reng, J., and Rury, M. A., Particle Adhesion Force in CMP and Subsequent Cleaning Processes," Proceedings, 4th International Chemical-Mechanical Planarization for ULSI Multilevel Interconnection Conference, Santa Clara, CA, Reb. 11-12,1999, pp. 61-64. 

Planarization- Chemical mechaniced planjurization machines are used to level the topology of the films deposited on the wafer. Chemical-mechanical smoothing is the process used to improve process uniformity, repeatability, removal rate, planarity and defeet reduction. Thus, planarization is requisite to producing defect-free CMOS circuits. 

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. 

B. Withers, E. Zhoa, R. Jairath, A Wide Margin CMP and Clean Process for Shallow Trench Isolation Applications, 1998 Proceedings of the Third International Chemical-Mechanical Planarization for VLSI Multilevel Interconnection Conference (CMP-MIC), Santa Clara, CA, pp. 319-327, Feb. 19-20,1998. 

A. Hu, X. Zhang, E. Sachs, P. Renteln, Application of Run by Run Controller to the Chemical-Mechanical Planarization Process, IEEE Proceeding of the 15th International... 

A. Hu, R. Chan, S. Chiao, Real Time Control of Chemical Mechanical Planarization (CMP) Process, First International Chemical-Mechanical Polish (CMP) for VLSI Multilevel Interconnection Conference, pp. 235-240, Feb. 22-23, 1996. 

D. Bramano and L. Racz Numerical Flow-Visualization of Slurry in a Chemical Mechanical Planarization Process, Proc. of CMP-MIC, pp. 185-192, Santa Clara, CA, Feb. 1998. 

C. Yu, P. C. Fazan, V. K. Mathews, and T. T. Doan, Dishing Effects in a Chemical Mechanical Polishing Planarization Process for Advanced Trench Isolation, Appl. Phys. Lett., vol. 61, no. 11, pp. 1344-1346, Sept. 1992. 

As the integrated circuit (IC) industry has chosen chemical mechanical planarization (CMP) as one of the indispensable processes in the generations of transistor gate lengths equal to or smaller than 0.35/im, it is imperative that the CMP-related process problems be investigated and... 

Why is tribology important for the chemical-mechanical planarization process ... 

The chemical-mechanical polishing or planarization (CMP) process is a complex interplay between the wafer and the consumables involved. The consumables include slurry, pad, conditioner, and so on. During polishing, the pad carries the slurry and delivers it to the wafer surface. It also transmits the normal and shear forces from the polisher to the wafer. Therefore, polishing pad plays a critical role in the CMP process and influences the outcomes such as material removal rate (MRR), within-wafer nonuniformity (WIWNU), wafer-to-wafer nonuniformity (WTWNU), step height reduction efficiency (SHRE), and defect counts. 

The chemical component of CMP slurry creates porous unstable oxides or soluble surface complexes. The slurries are designed to have additives that initiate the above reactions. The mechanical component of the process removes the above-formed films by abrasion. In most planarization systems the mechanical component is the rate-limiting step. As soon as the formed porous film is removed, a new one is formed and planarization proceeds. Therefore, the removal rate is directly proportional to the applied pressure. To achieve practical copper removal rates, pressures greater than 3 psi are often required. These pressures should not create delamination, material deformation, or cracking on dense or relatively dense dielectrics used in silicon microfabrication on conventional dielectrics. However, the introduction of porous ultra-low-fc (low dielectric constant) materials will require a low downpressure (< 1 psi) polishing to maintain the structural integrity of the device [7-9]. It is expected that dielectrics with k value less than 2.4 will require a planarization process of 1 psi downpressure or less when they are introduced to production. It is expected that this process requirement will become even more important for the 45-nm technology node [10]. 

Roy SR, Ali I, Shinn G, Furusawa N, Shah R, Peterman S, Witt K, Eastman S. Post chemical-mechanical planarization cleanup process for interlayer dielectric films. ECS 1995 312(l) 216-226. 

Chatterjee A, Kwok SP, Ali I, Joyner K, Shinn G, Chen I-C. Chemical mechanical planarization (CMP) process windows in shallow trench isolation for advanced CMOS. Electrochem Soc Proc 1996 96-22 219-227. 

Boyd JM, Ellul JP. A one-step shallow trench global planarization process using chemical mechanical polishing. ECS Proc 1996 95-5 290. 

This chapter gives an overview of the defects that can be generated or revealed during chemical-mechanical planarization (CMP). Most defects are specific to the type of CMP operation the wafer has just experienced. For this and other obvious reasons, this chapter is organized by CMP applications. However, there are some families of defects that are common to most CMP processes. Indeed, scratches [1-5], remaining particles [6], and surface residues [7] could be found in all CMP applications. Therefore, the materials are presented in the order of complexity, from the simplest such as oxide CMP to the most sophisticated such as copper CMP. Almost all defects presented in oxide CMP could exist in the other applications such as poly-Si, W CMP, and Cu CMP. 

Lin CF, Tseng W, Fengand M, Wang Y. A ULSI shallow trench isolation process through the integration of multilayered dielectric process and chemical-mechanical planarization. Thin Solid Films 1999 22 248-252. 

Treichel H, Frausto R, Srivastan S, Whithers B. Process optimization of dielectrics chemical-mechanical planarization processes for ultralarge scale integration multilevel metallization. J Vac Sci Technol A 1999 17.4 1160-1167. 

Nanoceramic Particulates for Chemical Mechanical Planarization in the Ultra Large Scale Integration Fabrication Process... 

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