三維異質整合技術之低溫混合接合於發光二極 體元件應用

Abstract

晶圓接合是三維積體電路中極為關鍵的技術之一。此篇研究開發了異質基板的整合使用銅/銦對高分子聚合物/二氧化矽低溫混合接合技術 ，並提出新穎的三維發光二極體元件的整合概念。低溫接合的主要優勢是為了降低製程過程中的熱預算，並且減緩熱膨脹係數不匹配對於異質基板接合造成的影響。銅/銦接合可以在低溫下進行，並且有良好的接合品質與電性表現。此外，本篇研究針對高分子聚合物/二氧化矽低溫接合進行探討 ， 並透過磨薄、高溫退火來檢驗其接合強度與高溫穩定度。為了達成銅/銦與高分子聚合物/二氧化矽同時接合，金屬與高分子聚合物的厚度控制便極為重要，因此實驗流程中各項參數必須精確控制。最終，我們結合了兩項不同的接合技術，同時應用於矽基板之同質整合與矽基板/藍寶石基板之異質整合，除了可以應用於三維發光二極體元件，也能應用於其他異質基板的整合。

Wafer bonding technique is one of the key technologies in 3D-IC applications. In this research, we develop the hybrid Cu/In to polymer/oxide low temperature bonding on heterogeneous substrates integration and propose a novel concept of 3D LED integration. The main reason for low temperature bonding is to meet the requirement of low thermal budget and mitigate the CTE mismatch problem in heterogeneous substrate bonding. Cu/In interconnects can be bonded at low temperature with the great bonding quality and exhibit excellent electrical performance, which have already been well-studied.

In addition, polymer to oxide bonding at low temperature is investigated followed by grinding and high temperature annealing tests to examine the bonding strength and thermal stability . In order to obtain the simultaneous bonding between Cu/In and polymer/oxide, the thickness control of metal and polymer is extremely important. Therefore, all the experimental parameters in the fabrication process flow must be optimized properly. Finally, we combine these two bonding techniques to realize the hybrid bonding on Si/Si and Si/sapphire substrates, which can be applied to 3D LED or other heterogeneous substrate integrations.