Fabrication of In-Situ MgB₂ films using evaporation and sputtering simultaneous deposition technique

The evaporation and sputtering simultaneous deposition (ESSD) system was developed for in-situ deposition of MgB₂ thin films. Mg was evaporated from the nozzle of cylinder crucible which is heated by high frequency induction heating, while B was sputtered by RF-magnetron sputtering. The nozzle-substrate distance was small enough to keep high vapor pressure of Mg on the substrate. The Mg-flux coming out of the nozzle was controlled by means of regulating the temperature of Mg source, was monitored and was calculated in detail with the variation of the distance from its nozzle. The optimal deposition condition with the variations of substrate temperature, the temperature of Mg source and the power of RF-magnetron sputtering, was investigated. MgB₂ films with onset T_c of 14 K was obtained. The Tc of the film is lower than the bulk value of 39 K. Further works are in progress to improve the quality of MgB2 films by further optimization of deposition parameters and improvement of the ESSD system.