Third-generation polishers

Raw throughput is higher (second- and third-generation polishers produce 25 to 60 wfr/hr in production). 

Emphasis in CMP technology in 1998-1999 has evolved from a nearly exclusive focus on traditional polish systems to the use in manufacturing of advanced second- and third-generation polishers. This advance in technology has translated into standard CMP processes for oxide, polysilicon, and tungsten CMP, and expanded interest in aluminum CMP, copper CMP,... 

In this period, there is no newly generated erosion because of the same removal rates in both areas as shown in Fig.2(c). During the third step, oxide layer that remains after the second step is polished in blanket area, whereas mixture of oxide and nitride is polished in the patterned area. Because the removal rate of the oxide/nitride mixed area is smaller than that of oxide, the erosion that is generated in first step decreases with polishing time during the third step. The final step is defined as the period in which erosion is generated due to the difference of removal rate between the mixed area and the nitride area as shown in Fig,2(d). In order to quantify and elucidate the STI CMP as explained above, some simple relations which can predict the post STI CMP erosion were derived. 

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