Papers by Author: Chang Ki Hong

Abstract: The present work reports a method to prevent the condensation defects on contact hole patterns by improving the rinsing process after a dry etching. In general, residual gases on the surface after the dry etching can be easily removed by using a DI water rinse. However, the residual gas can not be completely removed in high aspect ratio contact holes, resulting in the condensation defect. In this work, in order to completely remove the residual gas inside the contact holes, several rinse processes were employed such as a megasonic rinse, a sequential rinse and a hot temperature rinse. These proposed rinse methods were effective in eliminating the residual dry etching gases in the high aspect ratio contact holes and thus were able to remove condensation defects on contact holes.

Abstract: The purpose of this study is to investigate the effects of slurry pH on the adhesion and removal of silica and ceria abrasive particles on the poly Si, TEOS, SiN and SAC (self aligned memory cell contact) and STI (shallow trench isolation) patterned wafer surfaces. The adhesion force of silica and ceria particles were theoretically and experimentally investigated in STI and poly Si CMP process. A stronger adhesion force was observed for silica particles on the poly Si wafer in acidic rather than in alkaline solutions. The adhesion force of ceria particle was lower than that of silica in investigated pH ranges. STI patterned wafer showed lower adhesion force than SAC patterned wafer. Lower adhesion force between particles and surface resulted in a lower level of particle contamination.