Utilitarian Information for CMP Scientists and Engineers

In this chapter, a collection of practical information that is useful for CMP scientists and engineers is presented. In addition to some physical and chemical properties of the key materials commonly used in CMP, some commercial sources for these materials are also included. Because of the highly dynamic nature of the industry, it is certain that the list is incomplete and the readers are encouraged to check out the corresponding Web sites for any updates or changes. 

Abrasive particles are a key component in CMP slurry. The most commonly used abrasive particles include silica, alumina, ceria, zirconia, titania, and diamond. Table 21.1 listed a set of information on each type of abrasive particles such as density, microhardness, and isoelectric points (lEP). It is important to point out that the specific values for these properties depend highly on the preparation techniques and the specific states of the samples. The values listed in the table represent an average of the most commonly reported data. For example, the isoelectric point for silica is a function of the number of hydroxyl groups, type and level of adsorbed species, metal impurity in the solid matrix, and the treatment history of the materials [1]. There are three major types of silica according to their preparation methods fumed, colloidal, and precipitated. The common sources for obtaining these abrasive particles are listed in Table 21.2. As examples, some of the more specific information on 

Microelectronic Applications of Chemical Mechanical Planarization, Edited by Yuzhuo Li Copyright 2008 John Wiley Sons, Inc. 

When selecting an abrasive particle for a CMP application, many factors may influence the decision, such as the bulk and surface properties of the particles. 

Colloidal silica NexSil aqueous colloidal silica (NYACOL, www.nyacol.com) LUDOX colloidal silica (SIGMA-ALDRICH, Inc., http / / WWW. sigmaaldrich. com  

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UTILITARIAN INFORMATION FOR CMP SCIENTISTS AND ENGINEERS TABLE 21.1 Physical Properties of Abrasive Particles. ... 

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