Post Chemical Mechanical Planarization (CMP) Cleaning Using Hydrogen Dissolved Water

Abstract

In current semiconductor manufacturing process, especially chemical mechanical manufacturing (CMP) process, ceria nanoparticle dispersed slurry is well known consumable for various CMP processes such as shallow trench isolation (STI), inter layer dielectric (ILD) CMP process, and etc. After CMP process, the ceria nanoparticles which are the sources of defects must be removed surely before performing the other processes. Typically, Standard clean solutions such as SC-1, SC-2, and etc. are applied to the post CMP cleaning process. These cleaning solutions are still effective to remove the residual ceria particles but there are several disadvantages such as quite harmful for health and need of additional treatments for wastewater. In this study, cleaning efficiency of the H2 gas dissolved water was evaluated comparing with DIW and other standard cleaning solutions. 4x4 cm2 of silicon dioxide film wafers were polished supplying ceria slurry and then immersed into the cleaning solutions such as DIW, standard clean solutions, and H2 dissolved water, respectively. Finally, we quantitively analyzed the residual cerium dioxide on the cleaned wafer surface by using inductively coupled plasma mass spectrometer (ICP-MS). H2 dissolved water removed residual ceria nano particles from the silicon dioxide film considerably comparing to DIW. Figure 1. show residual ceria ion concentration after cleaning process and cleaning efficiency calculated. Figure 1