Investigation of copper layers deposited by CVD using Cu(I)hfac(TMVS) precursor
Investigation of copper layers deposited by CVD using Cu(I)hfac(TMVS) precursor
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研究使用 Cu(I)hfac(TMVS) 前驱体通过 CVD 沉积的铜层
DOI：
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发表时间：
2005
期刊：
影响因子：
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通讯作者：
H. Gamble
中科院分区：
文献类型：
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作者：
B. Toh;D. McNeill;H. Gamble
在不锈钢反应器中，以六氟乙酰丙酮三甲基乙烯基硅烷(Cu(I)HFAC(TMVS))为前驱体，氮气(N2)为载气，在钛涂层衬底上进行了铜的化学气相沉积(CVD)。研究了沉积温度、工艺压力和工艺气体流量比对薄膜电阻率、薄膜成分和表面形貌的影响。获得的最低电阻率值约为2μΩcm。此外，使用LEO扫描电子显微镜成像系统对铜膜的横截面检查表明，在较高的沉积温度下，铜膜的孔隙率增加。确定了最佳载气流量：较高的载气流量会导致铜前驱体的过度稀释，而较低的载气流量会削弱铜前驱体向衬底的传输。X-射线衍射仪分析表明，当热处理温度超过450min时，会形成氧化铜(Cu2O)。FIB/∘成像显示，在0.25μm宽和0.5μm深的沟槽中，化学气相沉积铜具有比物理气相沉积铜更好的整合性和通孔。经玻璃上旋转电介质钝化的CVD铜层，与未钝化的铜层相比，铜原子的表面迁移减少。发现以(111)取向为主的铜膜表现出比(111)和(200)混合取向的铜膜更长的电迁移寿命。
Chemical vapour deposition (CVD) of copper on titanium-coated substrates was performed in a stainless steel reactor using copper(I) hexafluoroacetylacetonate trimethylvinylsilane (Cu(I)hfac(TMVS)) as a precursor and nitrogen (N2) as carrier gas. Film resistivity, film composition and surface morphology were studied in relation to deposition temperature, process pressure and process gas flow ratio. The lowest resistivity value obtained was around 2 μΩcm. In addition, cross-sectional examination of the copper films, using a LEO SEM imaging system, indicated increased film porosity at higher deposition temperatures. An optimum carrier gas flow rate was determined: higher carrier gas flow rates caused excessive dilution of the copper precursor, whilst lower carrier gas flow rates weakened the transport of the copper precursor to the substrate. XRD data revealed formation of copper oxide (Cu2O) if annealing temperatures exceeded 450∘C for a period of 30 min.FIB/TEM imaging revealed that CVD copper offers better conformality and viafilling than PVD copper in trenches 0.25 μm wide and 0.5 μm deep. CVD copper layers, passivated by a spin-on-glass dielectric, were shown to have reduced surface migration of copper atoms, compared to unpassivated layers. Copper films with a predominantly (111) orientation were found to exhibit a longer electromigration lifetime than copper films with mixed (111) and (200) orientations.