Here is the abstract you requested from the IMAPS_2013 technical program page. This is the original abstract submitted by the author. Any changes to the technical content of the final manuscript published by IMAPS or the presentation that is given during the event is done by the author, not IMAPS.
|Monitoring of Wet Etch for Wafer Thinning and Via Reveal process|
|Keywords: ViaReveal, Etch, Monitoring|
|TSV (Through Silicon Vias) are usually formed and deposited as a blind vias. As a last stage vias are opened by thinning of the back side of the wafer. While the bulk of the silicon can be removed by both wet and dry methods, the final step of “Via Reveal” process is predominately performed by wet etch. Two commonly used types of etching solutions are anisotropic alkaline etch (KOH. TMAH, etc) and isotropic etch (HF/HNO3, etc). Etch rate, uniformity, and characteristics of product strongly depend on the composition of solution: both original compounds and reaction products. This presentation will describe different approaches for process controls of both alkaline and acidic etch solutions using advanced spectroscopic modes and potentiometry. Pros and cons of different methods will be discussed. Specific emphasis will be made for the monitoring of Si and other reaction products. Examples from the semiconductor facilities will be provided.|
|Eugene Shalyt, Sr. R&D Manager