TempKoat™ N: FAQs
- TempKoat™ N is a chemically amplified, negative-tone plating resist intended for plating applications requiring a thick resist film.
- Advanced packaging and MEMS are major areas TempKoat™ N is intended to excel. This includes redistribution layer (RDL) plating, new 2.5D and 3D packaging requiring high aspect ratio pillars, and microbumps.
- The solvent contained in TempKoat™ N is PGMEA/Cyclopentanone.
- A primer is not required for applications on wafers with a deposited copper layer. For bare silicon wafers, HMDS priming is recommended.
- EBR is typically a necessary removal step intended to expose the bare copper substrate layer to contact the plating bath electrodes. Customers should use EBR PG for best EBR results.
- The PEB step is necessary to complete the thermally driven catalytic reaction that causes the exposed resist to become insoluble to the aqueous developer. A hard bake is not required, as the resist is meant to be temporary and stripped post-processing.
- While there are many commonly used alkaline electroplating chemistries (non-cyanide zinc and copper, as well as gold), we have focused on acidic bath reliability. Most of the market is copper and nickel. Customers should evaluate the material with their alkaline chemistries.
- Our subject matter experts at Technic Inc. confirm this a common step to remove both organic residue and oxides present on the wafer surface. Additionally, this step allows wetting of the surface to ensure complete patterned exposure to the electrolyte, and with that, improved plating uniformity.