Abstract
Both dry etching and wet etching are an integral part for the fabrication of semiconductor devices. However, both types of etching can cause problems such as surface degradation, uncontrollability of etching depth and undercut. For instance, aqueous HF (wet etching) and dry etching are used to etch SiO2 films. During HF partial etch (SiO2 is not fully removed), it introduces some interesting phenomena such as adhesion degradation on SiO2 surface morphology which is not present when SiO2 is fully etched. This paper reports the first study of systematical characterization of the SiO2 surface morphology after partial dry and HF wet etching and compares their different effects on the strength of adhesion on polaric and nonpolar liquids. To study the strength of adhesion, this experiment utilized two different types of resist such as PMMA resist and PMGI based LOR resist. Atomic Force Microscopy (AFM) was used to determine the surface morphology before and after dry etching and HF wet etching process. Telescope-Goniometer was used to measure the contact angles as an indicator of liquid-solid adhesion. From the comparison study it’s evident that partial wet etching by HF changes the surface morphology of the SiO2 significantly and degrades the adhesion between the resist and the surface. On the other hand, dry etching does not alter the SiO2 surface morphology significantly and it is recommended to use dry etching instead of HF wet etching to avoid the degradation in adhesion strength on SiO2 surface whenever possible. Next, as a more general approach, adhesion promoter was used to restore the adhesion between the resist and SiO2 surface.
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Disclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.