Vacuum Photothermal Processing (VPP) for Curing of the Complex Thin Film Systems

Vacuum photothermal processing (VPP) of complex thin films is reported The thermal process is based on exposure of thin films systems such as Al-Al₂Oi-Ge-Au and In₂O₃ deposited on glass substrates, to a non-coherent radiation of a tungsten coil heated to about 3000 °C in vacuum. This process is different from the conventional Rapid Thermal Processing (RTF) that uses glass sealed light sources as heaters, due to the significant role of high energetic photons. The experimental data indicate a decrease in the sheet resistance value of transparent conductive In₂O₃ thin films from about 1,000 Ω/Sq to an average resistance of 120 Ω/Sq. Another result is the increase of the film's homogeneity following the VPP treatment. VPP processing of semiconductor structures produces a healing effect in the crystalline lattice that has undergone irreversible breakdown before VPP. Furthermore, a clear shift of the volt-ampere characteristics of the semiconductor Al-Al₂O₃-Ge-Au thin film structure was observed after VPP: The system's resistance changes from 2.25 Ω to 0.76 Ω and the conduction voltage increases from 1.3 V to 3.3 V.