Integration of Chemically Amplified Photoresist and High-Speed Copper Plating Products for Advanced Packaging Applications

Abstract

Advanced packaging technologies require materials which will allow for better resolution of patterns associated with the ever more challenging device architecture, along with materials that will allow for higher throughput. Device throughput can be increased with imaging materials that have higher sensitivity and metallization chemistries with faster electrodeposition rates. Chemically amplified photoresists offer the advantages of excellent sensitivity and resolution with good process margins, coupled with excellent stripping performance and plating bath compatibility for the film thicknesses that are required in packaging applications. Electrolytic copper plating products with fast deposition rates are a key factor in decreasing wafer plating time and increasing throughput. However, it is the integration of the photoimaging material and the subsequent plating chemistry that is essential in producing metallized structures for copper pillar and solder applications. Because the profile of the resist image is directly transferred during the electroplating process, it is critical to have a well formed image that is resistant to the plating chemistry. Plating bath contamination and resist strippability are other key factors in producing void-free, defect-free structures. Dow's newly introduced chemically amplified material is capable of film thicknesses from 30um to 80um by a single coating process with good uniformity. Imaging and process latitude are demonstrated at 40um and 65um thicknesses with emphasis on sidewall profiles and sensitivity. Further, the photoresist compatibility with INTERVIA™ Cu 8540 Electroplating Copper Chemistry is shown, along with NIKAL™ BP Ni plating chemistry and SOLDERON™ BP TS 6000 SnAg plating chemistry compatibility. The improvements in product line from Dow's INTERVIA™ Cu 8540 to INTERVIA™ 9000 Electroplating Copper Chemistry is also demonstrated in the paper, with thickness uniformity, high plating speed, and tunable morphology highlighted for various applications. The power of integration has enabled the development of this suite of products designed for compatibility and superior performance for advanced packaging technologies. ™ Trademark of The Dow Chemical Company