Liquid Infiltration Mechanism for Cleaning in Deep Microholes

Liquid infiltration mechanism for cleaning high aspect ratio trenches and microholes of highly integrated semiconductor devices was considered by theoretical and experimental methods. It is theoretically predicted that liquid does not infiltrate into microhole with non-wettable liquid-solid contact surface. Increasing liquid pressure and/or decreasing inside gas pressure overcome the surface tension to infiltrate liquid into non-wettable microholes. On the other hand liquid can infiltrate into wettable microholes independent of microhole size. These theoretical predictions were confirmed by using non-destructive observation of high aspect ratio model structures.