奈米碳管結合栓塞結構於電漿處理後覆蓋銅金屬之特性研究

Abstract

本論文主要是探討化學氣相沈積參數對栓塞結構中奈米碳管生長情形之影響，及奈米碳管取代銅導線成為金屬內連線後，經由電漿表面處理，其與上層披覆銅的介面性質探討。 實驗首先以二氧化矽為介電材料在矽基材上製作孔洞陣列，並沉積TiN及Ni薄膜。接著以熱化學氣相沉積法於孔洞中合成奈米碳管，觀察不同孔洞大小以及不同製程參數對碳管的合成密度和長度之影響。再以NH3電漿對奈米碳管處理後覆蓋銅金屬進行奈米壓痕量測。 由掃瞄式電子顯微鏡觀察發現奈米碳管於製程溫度600°C、氫氣流量100sccm、碳源氣體流量(C2H4) 30sccm之製程參數下，可製備出長度及密度符合需求之奈米碳管。而栓塞結構中奈米碳管經10分鐘之電漿處理後達到平坦化之目的，且於紅外線光譜分析顯示電漿處理可去除碳管中雜質。而最後之奈米壓痕量測結果顯示，奈米碳管經電漿處理後覆蓋銅金屬，可提升異質介面之附著強度，增加結構之機械強度及可靠度。

This thesis investigated the effect of chemical vapor deposition parameters and ammonia plasma treatment on the carbon nanotubes(CNTs) / copper interface. Twenty nanometer-thick layer of TiN followed by a 7 nm layer of Ni and 300 nm TEOS-SiO2 dielectric layer were deposited on the cleaned Si substrate. Thermal CVD was employed to fabricate CNTs, the variation of density and length result from CVD parameters and size of via-hole were measured. Then copper were coated on CNTs/Via-hole after plasma treatment. The CNTs were grown in ethylene (C2H4 30sccm) and hydrogen (H2 100sccm) at 600°C by thermal CVD. High density CNTs were observed by scanning electron microscopy. Purification effects of ammonia plasma treatment have been observed by Fourier Transform Infrared spectroscopy. The nano-indentation testing results show that the adhesion strength of CNTs / copper interface with plasma treatment were higher than that without treatment. The mechanical properties and reliability of CNTs/Via-hole structure were also promoted.