IC mechanical planarization process incorporating two slurry compositions for faster material removal times

Abstract

The present invention relates to integrated circuits (ICs) fabrication. Particularly, there is a CMP process which incorporates small quantities of two chemicals. The first chemical is the standard slurry mixtures, like water, aluminum-oxide and hydrogen-peroxide mixed into a slurry. The second chemical is a strong base chemical, like KOH, or potassium hydroxide. Moreover, the CMP process utilizes a system of closely regulating the timing of the two chemical processes. Specifically, during a first time period, both chemicals are applied; thus providing a given speed of the chemical removal of tungsten material. During a second time period, the KOH is removed, so as to slow down the chemical action and facilitate a greater degree of planarization.

Dependencies are inferred from the claim text.