利用奈米鈀金屬粒子活化於感光型介電材料上進行無電鍍銅金屬化之研究

Abstract

本研究為利用奈米鈀金屬粒子作為無電鍍銅觸媒將感光型介電材料(Photoimageable dielectric, PID)進行金屬化，透過二階段改質的手法搭配新式金屬觸媒，試圖改善無電鍍銅於感光型介電材料上鍍不良及附著力不佳的缺點，並且取代現有乾式真空濺鍍的金屬化方式，成為降低成本並且提升生產效能的解決方案，首先使用半導體標準的RCA-SC1流程或氧氣電漿的方式將PID基板進行第一階段親水化處理，並利用末端含有胺基之矽烷化合物進行表面第二階段改質，使矽烷化合物形成自組裝薄膜層(Self-assembly monolayer, SAM)，再利用自行研發之聚乙烯醇保護奈米鈀金屬粒子(Polyvinyl alcohol, PVA-Pd)與矽烷化合物之胺基進行作用，以作為後續無電鍍銅之金屬觸媒並提升其無電鍍銅於PID上之覆蓋率與結合力。 在材料分析的部分，為了確認各階段改質處理對於材料表面的影響以及化學銅的結合力，利用接觸角量測儀(Contact angle measurement)、原子力顯微鏡(Atomic force microscopy, AFM)、掃描式電子顯微鏡(Scanning electron microscopy, SEM)、X射線螢光分析法(X-ray fluorescence analysis, XRF)、X射線光電子能譜儀 (X-ray photoelectron spectroscop, XPS)以及百格刀膠帶測試進行分析。

Electroless-deposition Copper (E’less Cu) is one of most commend technique in electronic package industry. In this work, two step surface modification technique is applied to set up an attachable surface by using RCA-SC1 (standard clean process of semiconductor industry) or radio frequency (RF) power plasma and the 3- 2-(2-aminoethylamino) ethylamino propyl trimethoxysilane (ETAS) for PVA-Pd attach which as the catalyst of E’less deposition. Applying the catalyst agent developed in previous study and synthesized in the laboratory. Using polyvinyl alcohol (PVA) as protective agent of the palladium nanoparticle with well-define size of 2-5nm. [1] The PID surface modification and the adhesion between PID and e’less Cu is evaluated by water contact angle, X-ray photoelectron spectroscopy (XPS), scanning electron microscope (SEM), atomic force microscope (AFM), X-ray fluorescence analysis (XRF) and cross cut test. The results showed that using PVA-Pd as catalyst of E’less Cu on PID had better adhesion than commercial Sn/Pd and applying plasma is more suitable method than RCA-SC1 for organic polymer as the surface hydrophilicity modification method. Based on SEM and AFM analysis, one of the factor to enhance the adhesion is that micro-morphology and roughness occurred after plasma process. The XPS analysis showed many functional groups generated after treatment it might be another factor to enhance adhesion performance of E’less Cu on PID. In the practical application point of view, this study demonstrate “wet process” alternative for PID metallization and try to resolve the mechanism of surface modification.