Conformal photo-resist coating technique in the through-silicon via of the semiconductor devices with the rotary atomising aerosol spray

Semiconductor devices are increasingly sophisticated in their application of three-dimensional laminated chips inside through-silicon via (TSV). TSV is a technology that connects the stacked chips using through electrodes instead of higher integrated circuits densities. In this report, we invented a new photo-resist coating method inside the TSV using the rotary atomising aerosol spray. We measured the characteristics of the flying droplets from the atomising aerosol spray nozzle by a shadow Doppler particle analyser (SDPA) to indicate that the new method is capable of coating the photo-resist inside the TSV. Furthermore, we tried to make the prototype coating system with the rotary atomising aerosol spray nozzle and run the experiments in to coat the photo-resist inside the TSV test element group (TEG) wafer. Results indicate that the photo-resist is coated on the TSV TEG wafer having opening diameter of 50 µm to 200 µm, depth of 50 µm and square pyramid via holes with tapered angle of 54.7 degrees by using the prototype equipment. It is confirmed that coating along the inner walls of via holes is feasible.