高分子材料聚醯亞胺應用於三維積體電路銅錫金屬混合式異質接合之製程開發

Application of Polyimide in Asymmetry Cu/Sn Hybrid Bonding for 3D Heterogeneous Integration

朱書燕(Shu-Yan Jhu)

指導教授 ： 陳冠能

國立交通大學/電機學院/電子工程系所/碩士(2018年)

摘要

三維積體電路具有縮小封裝架構、縮短RC時間延遲以及異質整合等優勢，被視為延伸摩爾定律的潛力技術。在三維積體電路關鍵技術中，接合技術扮演完成垂直堆疊概念的重要角色。在元件持續微縮的情況下，高密度金屬連接線使金屬間空洞填充技術面臨難以完全填補的困境。為此，同時完成金屬以及高分子材料接合的混合接合技術可以有效的解決此問題。
在混合接合技術中，金屬與高分子需要在同一個條件下接合並且與標準製程相容。傳統上聚醯亞胺材料因為高固化溫度而甚少使用於接合上，在此研究中，採用兩款低固化溫度的聚醯亞胺材料並且使用非對稱的結構以降低接合厚度。另外，為了降低熱預算，銅/錫接合技術也被採用來降低接合溫度。
在本研究中，設計了不同的聚醯亞胺材料對金屬厚度比例以研究製程適用範圍。在不同的厚度比例上兩款聚醯亞胺材料的結構都有良好的電性表現，特徵接觸阻值大部分都落在10-7~10-8Ω/cm2的範圍。此外，樣品均通過可靠度測試。綜合上述，兩款聚醯亞胺材料皆可完成低溫的高分子/金屬混合接合，對於未來應用於三維異質整合具有卓越潛力。

關鍵字

混合式異質接合 ； 三維積體電路 ； 聚醯亞胺 ； 銅錫金屬

並列摘要

Three-dimensional integrated circuits (3D ICs) become a promising candidate to extend Moore’s Law with advantages such as small form factor, low RC delay and heterogeneous integration. Among the key technologies in 3D IC, bonding technology plays an important role to fulfill vertical stacking concept. As electronic devices continue to scale down, it becomes harder to fill the air gaps because of high density metal interconnects. Hybrid bonding is a promising approach to solve this issue, which combines metal bonding and adhesive bonding that complete interconnection and passivation at the same time.
To carry out hybrid bonding, all the materials should be bonded together under the same condition and compatible with standard process. In the past, polyimide was seldom used in hybrid bonding due to its high curing temperature. In this thesis, two kinds of polyimides with low curing temperature were used to relieve thermal budget and asymmetric hybrid bonding scheme was adopted to reduce the thickness of bonding film. Besides, solder bonding was used with the aim of lowering the bonding temperature.
In order to investigate the bonding process window, different polyimide to metal thickness ratios were used. From the experiment results, both polyimides showed good electrical performance under all bonding process window. The specific contact resistances were both around 10-7~10-8Ω/cm2. Furthermore, all samples passed the reliability tests without significant degradation. Therefore, both polyimides are able to achieve low temperature wafer-level polymer/metal hybrid bonding scheme, which show their potential for future 3D heterogeneous integration applications.

並列關鍵字

Hybrid Bonding ； 3D Heterogeneous Integration ； Polyimide ； Cu/Sn

參考文獻

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