Papers by Keyword: Resist Removal

Abstract: The demand for higher functionality in smaller form-factor electronic devices continues to grow. This growth is enabled in large part by wafer-scale packaging technologies for 2-D, 2.5-D, and 3-D integration. Solder bump, copper pillar, and TSV processes are key enablers for advanced packaging. Sacrificial polymer materials such as photoresist and polyimides are used for patterning and/or passivation steps [1,2]. Typical challenges in removing these materials include long process times, short bath life, corrosion, sludge formation, and filter clogging. This paper presents a novel tool design that addresses these issues by a high rate of hydrodynamic agitation that maintains a thin boundary layer at the wafer surface. The outcome is quick removal and breakdown of the sacrificial layer, independent of pitch and without all the negative side effects.

Abstract: It is known that resist removal capability of SPM gradually deteriorates during the stripping process. The deterioration is theoretically explained to be the decrease in the concentration of sulfuric acid. On the contrary, in the case of electrolyzed sulfuric acid method, both concentrations of sulfuric acid and of peroxodisulfuric acid produced by electrolysis are kept constant, so that the resist removal capability is maintained for a long term even without addition of hydrogen peroxide. It is proved that resist patterned on φ300mm wafers and implanted at 1E14 atoms/cm² can be removed using electrolyzed sulfuric acid solution without ashing process.

Abstract: The removal of ion implanted photoresist (II-PR) after implantation of ultra shallow extension and halo regions is considered as one of the most challenging front-end-of-line (FEOL) processing steps for 32nm and beyond CMOS technology nodes. Commonly used resist strip processes such as fluorine-based dry plasma ash and hot sulfuric/peroxide mixtures induce unacceptable levels of oxidation and material loss [1-.

Abstract: We performed two experiments on resist-coated wafers. In the measurement of the resist-wafer adhesivity, we confirmed that it is significantly increased by an HMDS layer in between. In the resist-removal experiment using steam-water mixed spray, we found that the area of resist removal is limited within the area of spray application if HMDS is used, otherwise the former can be larger than the latter. These results suggest that the resist removal from a wafer surface by steam-water mixed spray is essentially a peel-off process.