錫／銅雙層金屬薄膜之界面反應與反應生成動力學研究

A Kinetic Study of Sn/Cu Bimetallic Thin Film Reaction

廖建能(C. N. Liao) ； 魏仲廷(C. T. Wei)

《材料科學與工程》 37卷2期 (2005/06) Pp. 82-86

https://doi.org/10.6409/JMSE.200506.0082

摘要

本實驗擬針對無鉛銲料中最主要之錫成分與球下金屬層中的銅成份之界面反應之做一系統性探討。實驗藉由濺鍍方式將銅膜沉積在氧化矽基板上，再用熱蒸鍍法於銅薄膜上鍍上錫膜，接著利用四點探針法於氮氣氣氛下以固定升溫速率由室溫升溫至220℃來觀測薄膜電阻變化，並以掃描式電子顯微鏡(SEM)及X光繞射法(XRD)分析薄膜介面微結構與介金屬生成相。研究結果指出錫－銅介金屬相(Cu6Sn5)生成活化能約為0.97±0.07eV。銅膜與錫膜的相對厚度亦會對介金屬相的生成順序造成影響，在等速率升溫退火過程所生成的介金屬化合物種類會因膜厚比例不同而有所差異。而較薄的錫／銅薄膜反應偶由於具較大之電阻變化因而對於薄膜反應生介金屬成相的偵測有較高的靈敏度。

關鍵字

薄膜反應 ； 薄膜電阻 ； 介金屬相 ； 活化能

並列摘要

A kinetic study of interfacial reaction and compound formation in a Cu/Sn thin film couple was conducted. The formation of Cu-Sn intermetallic compounds (IMC) in the thin film couple was explored by electrical resistivity measurement during an isochronal annealing process. The Sn/Cu bilayer thin films were prepared by consecutive deposition of Cu film and Sn film onto oxidized Si substrates by sputtering and evaporation methods, respectively. Resistances of the Cu-Sn bimetallic thin film specimens were measured using an in-situ 4-point probe method when the specimens were heated from room temperature to 220℃ at a fixed ramp rate in nitrogen ambient. The various Cu-Sn compounds were identified by X-ray diffraction (XRD), and the morphology of the Cu-Sn compounds was examined by scanning electron microscopy (SEM). The activation energy of formation of Cu6Sn5 compounds was determined to be 0.97±0.07eV according to the in-situ resistivity measurement. The thickness of the Sn/Cu bilayer thin films was found to affect the sequence of IMC formation. Besides, the thinner reaction couples showed a higher sensitivity for detecting the compound formation due to large change in thin film resistance.

並列關鍵字

interfacial reaction ； Resistances ； intermetallic compounds ； reaction energy