反应气体流量对CVD钽性能影响研究

Effect of Reactant Gas Flow Rate on Properties of Tantalum Layer Fabricated by Chemical Vapor Deposition

介绍了化学气相沉积（CVD）技术制备难熔金属钽涂层的原理及方法。利用TaC15-H2·HCl反应体系，以冷壁式化学气相沉积法在钼基体表面沉积了钽涂层。利用扫描电子显微镜（SEM）、X射线物相分析仪（XRD）、显微硬度计等分析手段，研究了反应气体（氢气、氯气）的流量变化对钽涂层的沉积速率、结构、表面形貌、硬度及密度等的影响；应用Harris公式，计算了钽涂层的织构系数，获得了钽涂层的择优取向。研究结果表明：随着氢气流量的增加，涂层沉积速率加快，随着氯气流量的增加，涂层的沉积速率则是先增加后减小；涂层由体心立方结构的钽（α—Ta）构成，表面形貌呈类金字塔形结构，涂层（200）晶面方向为最快生长方向；反应气体流量变化对涂层硬度及密度的影响均不明显；涂层维氏硬度在HV130．94～HV152．43之间，涂层致密性好，相对密度都在99．65％以上。

The principle and method of chemical vapor deposition （CVD） for preparing tantalum coatings were proposed. Tantalum coatings on the surface of molybdenum substrate were prepared by cold-wall CVD in TaCl5-H2-HCl system. The influences of reactant gas flow rate on deposition rate, structure, surface morphology, hardness and density were studied by scanning electron microscopy （ SEM）, X-ray diffraction analysis （XRD） and micro-hardness instrument. By using the Harris formula, the texture coefficient of tan- talum coatings was calculated, and the preferred orientation of tantalum coatings was obtained. The results showed that, with the in- crease of hydrogen flow rate, the deposition rate increased; with the increase of chlorine flow rate, the deposition rate increased first and then decreased. All the coatings consisted of α-Ta and its surface morphology was similar to pyramid. The fastest growth crystal face was （200）. The effect of reactant gas flow rate on the coatings＂ hardness and density was not obvious; the Vickers-hardness was between HV 130.94 - HV 152.43; all the coatings were dense and the relative density was above 99.65%.