Performance characterization of nonevaporable porous Ti getter films

The highly porous Ti film getters on (100) silicon substrates have been successfully grown by dc magnetron sputtering with varying glancing angle. The porous films were formed when the glancing angle was higher than 30°. The larger the glancing angle, the higher the porosity and specific surface area of the Ti films. The porous films were composed of isolated columnar crystals, and they have a larger capability to absorb oxygen than dense Ti films do. Differential scanning calorimetry analysis shows that the exothermal reaction temperature for a dense Ti film is 348 ° C . However, that for the porous Ti film ranges from 291 to 394 ° C . The suitable operation condition of porous Ti film getters can be evaluated using thermal desorption spectroscopy. The reversible and irreversible reactions may occur during gas desorption/adsorption of porous Ti films.