The Fabrication And Investigation Of Tantalum Thin Film Resistance

Along with the rapid development of modern science and technology, Computer and Microelectronics Science and Technology has also been greatly improved to the miniaturization. High precision and stability metal film resistors which resistances to harsh environment are important component of electronic machine. Develop the metal film resistors which have stable electrical properties, wide resistance range, smaller TCR, can adapt to harsh environment is an important thing and have broad application prospects. Ta thin film has a positive TCR, while the tantalum oxide film, compared with negative TCR. If able to take full advantage of tantalum and tantalum oxides to the opposite temperature characteristics of mutual compensation, are expected to prepare a wide range of electrical resistivity, low TCR thin film precision resistors. Carried out on the resistance of thin film materials, especially thin films of tantalum resistive element film-forming process and electrical properties of thin-film micro-structure, as well as the relationship between the mechanisms is particularly important. In this paper, we use tantalum as raw material, and deposition tantalum thin films on ceramic substrates by DC magnetron sputtering. We used orthogonal test method to carry on the experiment with different sputtering power, sputtering time as well as single and double-layer film, and then the corresponding samples were got a testing and analysis. Atomic force microscope (AFM) and scanning electron microscopy (SEM) were used to analyze the surface morphology and particle distribution of the films. X-ray energy dispersive spectroscopy (EDS) was used to analyze the film composition ratio; Agilent 34401a was used to analyze the thin film resistance changes with temperature and time. The results showed that: the lower sputtering power, the more surface defects. When the sputtering power is 81W the single-layer thin-film has the most uniform surface. But when the power was 96.25W the film is more easily to achieve zero TCR. The double-layer film got by compensatory model has more formation and stability also will be improved. Through appropriate distribution ratio we can get better thin-film resistors by compensatory model.