This work investigates the characteristics of ohmic contacts on an n-type Ge by combining TiO2 with different metals. Metal-insulator-semiconductor (MIS) structures easily crystallize after post-metal annealing (PMA), with the subsequent characteristics dependent on the insulator thickness and process temperature. If 2 nm thick TiO2 is doped with nitrogen, there is no obvious difference in the current-voltage characteristics before/after PMA. The transmission electron microscope (TEM) analysis also verified that a lightly nitrogen-doped process is useful in suppressing the crystalline transition. In this study, the tungsten (W) contact showed the best thermal stability. Therefore, this technique could be effective in suppressing TiO2 crystallization with improved thermal stability.
All Science Journal Classification (ASJC) codes
- Condensed Matter Physics
- Surfaces, Coatings and Films