Plasma Surface Treatment for Wafer‑Level Packaging Applications
As electronics continue to shrink and performance becomes more critical, manufacturers are turning to plasma treatment to support advanced wafer-level packaging (WLP) applications.
Plasma Cleaning for WLP
Plasma cleaning has traditionally been applied to remove contamination generated during device fabrication at the wafer level or during an upstream assembly process. In either case, cleaning the product to remove contamination such as fluorine, oxides, or metals significantly enhances the yield, reliability, and performance of the integrated circuit.
Photoresist Descum for WLP Using Plasma Treatment
Photoresist residue sometimes remains after development, processing, and resist strip. Plasma treatment provides uniform removal of small amounts of resist from the entire wafer surface before further post-processing.
Stripping & Etch for WLP Using Plasma Treatment
Dry plasma processing is an efficient method for bulk stripping and etching of materials, including photoresist, oxides, nitrides, and dielectrics. Achieve etch rates exceeding 1 micron per minute and uniformities greater than 95%. You can perform stripping and etching processes in wafer-level applications, MEMs manufacturing, and disk drive processing.
Wafer Surface Pre‑Treatment and Plasma Surface Activation
Plasma processing removes contamination and oxidation, improving reliability and bonding yields. Plasma also micro-roughens the wafer passivation layer, improving adhesion between the passivation layer and the board.
Plasma Surface Treatment for BCB and UBM Adhesion
Polymers, such as benzocyclobutene (BCB) and Under-Bump Metallization (UBM) layers, serve as dielectrics for the redistribution layer. Plasma treatment alters the topography and wettability of the wafer's original passivation layer, thereby promoting adhesion.
Dielectric Patterning for WLP Using Plasma Processing
Typical methods for forming the redistribution layer include patterning the dielectric redistribution material using standard photolithography. Plasma treatment is a viable alternative for dielectric patterning, allowing typical wet processing methods to be avoided.
Via Cleaning in Advanced WLP Using Plasma
Small vias formed in the wafer for stacked-die applications often leave residual material from the via-formation process. Optimized plasma configurations can effectively clean the vias without damaging the wafer surface.
Improving Bump Adhesion with Plasma Surface Treatment
Plasma cleaning can improve bump adhesion and increase bump shear strength. Plasma cleaning of the wafer surface improves bump adhesion and has been demonstrated to increase bump shear strength dramatically. Bump materials include solder of varying compositions and gold studs.
For expert guidance on integrating plasma technology into your process, contact our team at [email protected].