High melting point refractory tantalum (Ta) metal is frequently grown into thin film layer for many applications in biomedical implants, microelectronic devices and micro-level mechanical systems. Tantalum growth mechanism is still in debate and the inconsistent crystal phase outcome has puzzled many, though it is certain that the properties of the grown film are highly dependent on the formed crystal phase configuration. The microstructure, surface morphology, crystal orientation and residual stress of the sputter-deposited Ta thin films using direct current (DC) magnetron sputtering technique are studied at 0.4 Pa – 2 Pa of sputtering pressure, 100 W – 250 W of DC sputtering power on bare silicon and silicon dioxide substrate and 10 min – 50 min of sputtering duration. α-phase Ta is preferably grown at high sputtering time (high thickness) and high DC sputtering power (high growth rate). The sputtering pressure affects the thin film's microstructural porosity while the sputtering power controls the crystallisation's quality. Both sputtering pressure and power affect the generated argon plasma in the DC magnetron sputterer where α-phase Ta is preferably formed at high plasma. The presence of 3 μm silicon dioxide underlayer makes no difference compared to bare silicon substrate. Our study reveals that β-phase Ta is grown first irrespective of sputtering conditions and then transformed into α-phase Ta after reaching a certain thickness. The grown major α-phase content promotes small thin film sheet resistivity (58.9 μΩcm – 86.1 μΩcm) and is suspected to be the dominant factor that increases the compressive stress within the thin film layer and reduces the adhesion of Ta layer onto the substrate surface. The study has given a new insight in controlling the conductivity and adhesion level of Ta thin film based on the grown phase layer.

高熔点难熔钽（Ta）金属通常被生长成薄膜层，用于生物医学植入物，微电子设备和微型机械系统中的许多应用。钽的生长机理仍在争论之中，尽管可以肯定生长膜的特性高度依赖于所形成的晶相构型，但晶相不一致的结果困扰了许多人。研究了直流（DC）磁控溅射技术在0.4 Pa-2 Pa的溅射压力，100 W-250 W的DC溅射功率下溅射沉积Ta薄膜的微观结构，表面形态，晶体取向和残余应力。裸露的硅和二氧化硅衬底，溅射时间为10分钟至50分钟。α相Ta优选在高溅射时间（高厚度）和高DC溅射功率（高生长速率）下生长。溅射压力会影响薄膜的微结构孔隙率，而溅射功率会控制结晶质量。溅射压力和功率都影响在直流磁控溅射器中产生的氩等离子体，其中优选在高等离子体下形成α相Ta。与裸露的硅基板相比，存在3μm的二氧化硅底层没有任何区别。我们的研究表明，无论溅射条件如何，β相Ta都会先生长，然后达到一定厚度后转变为α相Ta。增加的主要α相含量可提高薄膜电阻率（58.9μΩcm– 86）。1μΩcm），并且被认为是增加薄膜层内压应力并降低Ta层在基板表面上的附着力的主要因素。该研究为控制基于生长相层的Ta薄膜的电导率和附着力水平提供了新的见识。