以亞胺基釩錯合物經化學氣相沉積碳氮化釩薄膜

Abstract

本實驗以VOCl3為起始物，與tBuNH2反應，成功的合成出tBuNVCl3之固體亞胺基釩錯合物。另外再與LiNEtMe反應，形成具良好揮發性之tBuNV(NEtMe)3液體。分別用NMR、EA、MS加以鑑定。 接著以tBuNV(NEtMe)3為單源前驅物，經過低壓化學氣相沉積法在n-type Si (100) 上成長薄膜。本實驗利用冷壁式反應器，前驅物汽化溫度為323K，沉積溫度為773K~923K。經XRD光譜顯示，薄膜具有多晶形結構，當載流氣體為氫氣時，其會沿著 ( 111 )晶面成長。從AFM分析結果，可得知薄膜之表面粗糙度為3.5~10.7 nm。由Auger之縱深圖譜分析可以得知，當利用Ar+ 濺射數分鐘後，顯示薄膜中主要的成分有V、 N、C三種元素，且均勻的分布在薄膜中。從ESCA測得V2p3/2、N1s 、C1s 及O1s 之電子束縛能分別為513.5eV、397.4eV、282.8eV及531.2eV。由EPMA之分析結果，薄膜之組成為VCxNy ( X=0.29~1.28，Y=0.67~1.22 )。反應過程中所產生之低沸點產物，經過分析後推測其可能之反應途徑。通氫氣為載流氣體時，薄膜之含碳量顯著降低，其組成偏向VN，當通入不同流量之氫氣並不會對薄膜之組成有太大之影響，而當沉積時基材性質之改變對薄膜組成之影響較大。

The imido complexes tBuNVCl3 and tBuNV(NEtMe)3 were successfully synthesized. NMR spectroscopy, mass spectroscopy and elemental analysis characterized these complexes. tBuNV(NEtMe)3 was used as a single-source precursor to deposit thin films on silicon substrates by low-pressure chemical vapor deposition. Deposition was carried out at temperature 773K~923K in a cold-wall reactor, while the precursor was vaporized at 323K. XRD analysis indicated that films exhibited polycrystalline structures. AFM studies indicated the root-mean square of roughness were 3.5~10.7 nm for the films. Elemental distribution within the films, study by AES depth profiling was uniform. ESCA showed that binding energies of the V2p3/2、N1s 、C1s and O1s electrons were 513.5eV、397.4eV、282.8eV and 531.2eV, respectively. EPMA studies indicated that film's composition was VCxNy ( X=0.5~1.28，Y=0.67~1.22 ) but while using hydrogen as carrier gas, small amount of carbon in the film VCxNy ( X=0.29~0.6，Y=0.82~0.94 ). The volatile byproducts were identified by nuclear magnetic resonance (NMR ) and possible reaction pathways were proposed.