銅-鎳薄膜鍵合技術之研究

The study of Cu-Ni thin-film bonding technique

許經世(Chin-Shih Hsu)

指導教授 ： 李天錫

國立中央大學/工學院/材料科學與工程研究所/碩士(2011年)

摘要

微機電固態照明以及航太機械產業中，鍵合晶圓對是相當重要的製程，特別是在接合強度，以及接合後的鍵合對在各種環境下測試是否會發生諸如材料的潛變、鬆弛或疲勞破壞以及鍵合後的內部應力問題；這些都是傳統冶金製程可能造成的問題，尤其冶金製程常用到高溫的熔煉或焊壓的製程，以致限制產品元件的製作；例如金屬鍵合的製程在LED 的基板也扮演了一個重要的角色，目前業界量產的主要材料為金銀晶圓鍵合對，主因其導電、導熱性良好，但也因其成本明顯的高於其他種類金屬鍵合對；此外也有擴散進入元件層的顧慮，因此不同的金屬擴散鍵合材料也被陸續的開發進而應用在LED製程裡。新材料的開發主要透過金屬對的二元相圖、晶格常數差異、熱膨脹係數及擴散係數四種方面做考量，是故篩選的條件非常的嚴苛，有很多組導電、導熱性良好且成本相較低廉的金屬晶圓鍵合對，因其物理性質方面的限制導致無法被開發，而本研究透過鍵合表面化學的處理方法，排除了這些物理條件的限制。
本實驗成功的利用浸泡HCl(aq)的方式，在200℃ [1.177M] 1hr 的參數使銅鎳晶圓對成功的鍵合，且其平均鍵合強度達到約0.54MPa；經過後續的OM及SEM 對表面做觀測及EDS 元素成分分析更加確立了此種方法的可行性，為金屬接合開啟了低溫化學鍵合的新製程。

關鍵字

低溫化學鍵合 ； 鹽酸 ； 金屬擴散鍵合 ； 銅鎳晶圓對

並列摘要

Wafer bonding is a critical processing technique in MEMS and aerospace industry. It contains several potential problems such as Creep, Relaxation and Fatigue under the tests of varieties of environmental condition due to the traditional metallurgical processing. In addition, high
temperature process such as welding and rolling are required, and the manufacturing processes limit the development of produces and elements. For example, metallic bonding technique plays a crucial role in LED
substrate; Au-Ag wafer bonding pairs is the main material in massive production. The obvious advantages of Au-Ag wafer bonding pairs are their high electrical and thermal conductivity, but the drawback is that they are highly costly. A variety of new wafer bonding pairs are being
developed consistently and applied in LED manufacturing process. The development of new materials mainly depends on their physical properties such as binary phase diagram, the difference of lattice mismatch, CTE (coefficient of thermal expansion) and diffusivity; the limitations are very strict. Many materials with good electrical and
thermal conductivity with lower-cost cannot be developed because of their other poor mechanical properties. The bonding surface chemical treatment will be applied in this study so as to make a brand-new process which completely rules the physical limitations out.
The immersion of Cu-Ni bonding pairs in hydrochloric acid makes bonding pairs successfully bonding at 200℃ [1.177M] 1hr in this study, and the average maximum bonding strength can attains 0.54MPa. OM (Optical micrograph)、SEM (Scanic electron micrograph) and EDS (Electronic Data Systems) are used to observe and analyze the surface after the chemical treatment which further ascertain the feasibility and open a new era for low-temperature metallic bonding.

並列關鍵字

Hydrochloric acid ； Cu-Ni wafer bonding ； Low-temper

參考文獻

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