Prevention of Condensation Defects on Contact Patterns by Improving Rinse Process

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.