Research On High Aspect Ratio TSV Cleaning Technology Enhanced By Megasonic

Higher density is always an important parameter for a new semiconductor technical application. Vertical interconnection using TSV (through silicon via) is recognized as an advanced approach for enhanced system performance in packaging and integration technologies.TSV is regarded as the key technology and the developing trend of 3D system in tegration. Therefor TSV technology have been more and more interested, lots of effort was spent on TSV process develop. Nowadays, the aspect ratio of TSVs has achieved about 10, which is still increasing. While, there are still lots of challenges in the TSV fabrication processes, post-cleaning after via etching is one of the challeng ing steps. The work in this thesis is focus on high aspect ratio TSV cleaning process study.Firstly, the fluidic characteristic of cleaning chemiclas in TSV and the by-product spe cies of TSV etching process are analyzed. The space alternated phase shift (SAPS) me gasonic cleaning technique based on common cleaning chemicals is discussed. And th e proposed cleaning characteristic and its impact on related processes are briefed. Bef ore TSV cleaning process, a TSVs of 20?m in diameter,200?m in depth, were fabricated in 8 inch wafer. TSV fabrication processes were well developed for experiment sample preparing, including TSV lithography processes, Bocsh Deep reactive-ion etching process, photo-resistor removing. Then, an optimized TSV clean solution with SAPS (Space Alternated Phase Shift) Megasonic is proposed.The thesis provides a feasible method and reference for TSV cleaning process and the development and application of TSV technology through the study of Bocsh etching, SAPS megasonic cleaning, and wafer level cleaning processes. Experiments prove that SAPS megasonic enhanced TSV cleaning is effective on residue removal inside blind vias.