鎳鈷矽化物及鎳鈷矽鍺化物薄膜之特性探討

The characteristics of NiCo thin film on Si and SiGe substrates

鄭祺萱(Chi-Hsuan Cheng)

指導教授 ： 辛正倫 ； 李佩雯

國立中央大學/資訊電機學院/電機工程學系/碩士(2014年)

摘要

本論文提出使用鎳鈷合金NiCo ( Co 10 at.% )當作互補式金屬氧化物半導體( CMOS )之汲極與源極的金屬連結材料，藉由濺鍍法沉積NiCo在矽或矽鍺基材上，再經由快速熱退火形成鎳鈷矽化物( NiCo silicide )或鎳鈷矽鍺化物( NiCo germanosilicide )去探討其材料特性。使用材料分析儀器包含：四點探針、掃描式電子顯微鏡、掃描式穿透式電子顯微鏡、能量散佈分析儀及低掠角X射線繞射分析儀。在此論文中也針對先前所廣泛使用的鎳矽化物( Ni silicide )、鎳矽鍺化物( Ni germanosilicide )、鎳鉑矽化物( NiPt silicide )、鎳鉑矽鍺化物( NiPt germanosilicide )與本論文所提出的NiCo silicide和NiCo germanosilicide去比較其材料特性差異。以熱穩定性來說，NiCo silicide能穩定至900℃，NiCo germanosilicide能穩定至600℃。由於Co的加入，可以使得NiCo在高溫依然可以得到相較於一般Ni silicide低的片電阻值，歸因於低溫相CoSi所造成的結果。在最後也探討了不同鍺濃度的矽鍺基材之NiCo germanosilicide的片電阻值變化與表面形貌變化。
本文所探討的鎳鈷合金的材料特性，對於金屬連接材料的選擇，提供了特性更好的選擇性，往後有利於微縮電晶體尺寸時所可以使用的材料。

關鍵字

鎳鈷 ； 矽鍺 ； 金屬矽化物

並列摘要

NiCo (10 at.% of Co) alloy was employed for the formation of the metal silicide and germanosilicide as the contact layer for future CMOS source/drain. The resistivity and structure evolution of NiCo silicide and germanosilicide were investigated, and the performance of the NiCo silicide is better than conventional NiSi and compatible with NiPt silicides, not with the NiPt germanosilicide yet. The thermal stability and enhanced sheet resistance of NiCo silicide and germanosilicide were found to be up to 900℃ and 600℃, respectively. The low sheet resistance was attributed to the low-temperature CoSi by enhancing the high temperature thermal stability and uniformity of the Ge. The influence of Ge concentration was studied in different Si1-xGex substrates, and the low sheet resistance can be reliable up to 650 ℃.

參考文獻

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