Reaction steps of silicidation in ZrO2/SiO2/Si layered structure

Reaction steps of silicidation in ZrO2/SiO2/Si layered structure have been investigated in terms of ultrahigh vacuum annealing. Comparison of 2- and 20-nm ZrO2 films at 920 °C revealed that the trigger of silicidation is the contact of ZrO2, SiO, and Si accompanying disappearance of interfacial SiO2 layer due to SiO desorption. In the contact position, a small amount of SiO gas can easily change ZrO2 to ZrSi2. Moreover, this reaction model is also applicable to the silicidation of gate polycrystalline-Si (poly-Si)/ZrO2 interface.