The Preparation and Study of In-ga-zn-o(IGZO) Thin Film
|School||Huazhong University of Science and Technology|
|Keywords||IGZO film Magnetron sputtering Optical and electrical properties Sputtering parameters|
ITO films optoelectronic integrated optimal performance transparent conductive oxide films, one in the industry also has a wide range of applications, but the the ITO film's raw metal indium resources scarce, so in recent years, researchers have been looking for ITO films alternatives, ZnO doped series film became the the ITO film's best alternatives for its excellent performance. The present study, the low levels of indium and gallium-doped ZnO prepared high density IGZO target, and changing the substrate temperature, sputtering time, sputtering power, target-substrate distance using RF magnetron sputtering, sputtering pressure a series IGZO film prepared under the conditions, the use of X-ray diffraction instrument (XRD), scanning electron microscopy (SEM), Hall Effect Instrument (Hall-effect device), UV - visible spectrophotometer (UV-vis spectrometer) testing means to characterize the performance of IGZO films to study the influence of process parameters on film structure, morphology and optoelectronic properties, and get some guidance results. IGZO film structural properties and the surface morphology of the substrate temperature is relatively large, as the substrate temperature increases, the strongest peak in the XRD pattern of the film changed from (100) (002) and subsequently converted to (103) direction. Tapered island structure of the organizational structure of the surface of the film deposited in the different substrate temperatures, the substrate temperature from 150 ℃ rose to 350 ° C. The process of the island structure is more obvious when the substrate temperature exceeds 400 ° C, the boundaries between the particles blurred island structure gradually disappeared, and the roughness of the film decreased. The sputtering time and sputtering power is increased within a certain range to improve the crystalline properties of the film, the island-like structure of the film surface increases. With the increase in the resistivity of the sputtering pressure and target-substrate distance showed the first decrease and then increase the trend. With the increase of the sputtering time, the resistivity decreased. The rise of the substrate temperature while increasing the carrier concentration and carrier mobility of the film, thereby improving the conductive properties of the film. When the target-substrate distance is 55mm, the sputtering gas pressure of 0.5 Pa, a sputtering time of 20min, and the sputtering power was 200W, the substrate temperature of 450 ° C, IGZO film having the lowest resistivity of 6.83 × 10 -4 sup> Ω.cm, the carrier concentration of 2.44 × 10 20 sup> cm -3 sup> Hall mobility of 37.5cm 2 sup> V -1 sup> S -1 sup>. With the increase of sputtering pressure and target-substrate distance, the the IGZO film's visible on average through the first increased and then decreased. With the increase of the sputtering time, and the sputtering power, the average visible transmittance of the IGZO film showed a downward trend. There is no obvious pattern of impact of the substrate temperature on the average visible transmittance of the film, but the temperature exceeds 350 ℃ after the improvement of thin-film crystalline and roughness decreased to improve the transmittance of the film. When the target-substrate distance is 55mm, sputtering gas pressure of 0.5Pa, the sputtering time of 5min, the sputtering power of 200W, the substrate temperature of 300 ° C, the film has the highest average visible transmittance of 76.45% (relative to the visible light of the glass substrate The average transmittance of 84.94%).