An evaluation of the HotOzoneTM process: a new post etch resist and residue removal process

The HotOzone^TM process, a new ozone-water cleaning process for post-contact/via oxide etch or post-metal etch resist or residue removal, is evaluated. Test structures, using 0.35 μm technology with I-line resist or 0.18 μm technology with DUV resist, are fabricated on 150 mm wafers and then etched. In the first series the structures are not ashed before being subjected to the HotOzone^TM cleaning process. In the second series the structures are oxygen plasma ashed before being subjected to the HotOzone^TM cleaning process. Cross-section SEM photographs provide a preliminary assessment of the cleaning performance and corrosion performance of the new process implemented in a single wafer processing configuration with a cleaning time of 1.5 minutes or 3.0 minutes. This new process has demonstrated the potential to replace both the traditional oxygen plasma ashing and the post etch solvent clean processes for the post metal etch cleaning