Dynamic Mechanisms of Chemical Mechanical Polishing Based on Frictional Characteristics

摘要

Chemical mechanical polishing (CMP) is a technique for effectively scraping off (wearing off) the surface layer of a test specimen by sliding the surface of the test specimen against a polishing pad through an abrasive material (slurry). In the field of tribology, attempts are generally made to reduce friction of sliding parts and to control wear, but in that case, the objective is fully opposite. Development of present-day CMP to produce ultralarge-scale integrated circuits (ULSI) probably started in the United States in 1991 from the method of damascene using tungsten (W) films and the flattening of quartz glass (SiO{sub}2) films. However, in Japan, CMP was developed earlier and the first in world application for the patent using the damascene method was made in Japan in 1974. CMP became an indispensable technique for W and Cu wiring formation and the planarization of the surface of interlaminar insulated films of multilayer wiring and elements, such as transistors, for ULSI. In this work, results obtained by analyzing chemical mechanisms focusing attention on friction characteristics in CMP are considered.