Thin Film Synthesis of High-Conductive Tungsten Nitrides and Furactal Analysis

1.采用低压化学气相沉积（CVD）方法研究了生长参数（沉积温度和气体成分）对氮化钨沉积速率的影响。在0.12 kPa的WF_6-NH_3-H_2（Ar）混合气体中，在Si（100）衬底上沉积了β-W_2N。在较低的温度下形成非晶W_2N，但在高于500 ℃时，W_2N（200）和（111）晶面优先取向在（100）面上。2. W_2N沉积的反应级数分别为1.0，0.65和0，对应于WF_6，NH_3和H_2。结果表明，氮化钨的形成主要受WF_6与NH_3表面反应的限制。3.氮化钨是一种间隙化合物，W-N键合状态不清楚。4.对氮化温度对氮化钼表面形貌和反应活性进行了分形分析。氮化温度从500 ℃提高到700 ℃和900 ℃时，氮化钼表面的分形维数分别从2.1增加到2.5和2.8。结果表明，氮化钼表面结构的不规则性随着氮化温度的提高而增加。

1.The dependence of growth parameters (deposition temperature and gas composition) on the deposition rate of tungsten nitride was studied by chemical vapor deposition (CVD) under low pressure. Tungsten nitride (beta-W_2N) was deposited on a silicon (100) substrate in a gas mixture of WF_6-NH_3-H_2 (in Ar) at 0.12 kPa. The film of tungsten nitride was formed at temperatures of 250 to 800ﾟC.Amorphous W_2N was formed at lower temperatures, but W_2N (200) and (111) faces were preferably orientated on to silicon (100) above 500ﾟC.2.The reaction orders for W_2N deposition were 1.0,0.65 and 0 with respect to WF_6, NH_3 and H_2, respectively. From these results, the formation of tungsten nitride is considered to be more limited by surface reaction of WF_6 with NH_3.3.Tungsten nitride was an interstitial compound with unclear W-N bonding state.4.Fractal analysis of the surface of Mo nitrides was performed in surface morphology and reactivity of the nitrides with varying nitriding temperature. The Fractal dimension of the surface of the Mo nitrides was increased from 2.1 to 2.5 and 2.8 with increasing nitriding temperature of 500ﾟC to 700ﾟC and 900ﾟC.The results indicated that an irregularity of the surface structure of the Mo nitrides increased with increasing nitriding temperature.