Nitrogen deficiency and metal dopant induced sub-stoichiometry in titanium nitride thin films: a comparative study

作者：Vasu Kuraganti; Kiran Mangalampalli Sri Rama Narasimha; Krishna Mamidipudi Ghanashyam; Padmanabhan Kuppuswamy Anantha^*

来源：International Journal of Materials Research, 2013, 104(9): 879-884.

DOI：10.3139/146.110938

• Magnetron sputtering
• Non-stoichiometric compounds
• Nitrides of titanium
• anion deficiency
• cation substitution

Sub-stoichiometric (nitrogen-deficient) and Nb-substituted (Ti1-yNbyN, 0 %26lt;= y %26lt;= 1) titanium nitride thin films were deposited by means of radio frequency magnetron sputtering on SiO2 and Si (311) substrates and compared. Thickness of TiNx films varied in the range 116-230 nm, while the value was constant, at 500 nm, for Ti1-yNbyN films. The sub-stoichiometric TiNx films deposited at room temperature are amorphous, independent of nitrogen partial pressure (in the range of 1.6 to 3.33 Pa). Annealing of the films at 600 degrees C resulted in amorphous crystalline transition only in the film deposited at 3.33 Pa, which crystallized into tetragonal epsilon-Ti2N phase. The other films remained amorphous. The hardness and Young%26apos;s modulus were highest for the film deposited at a nitrogen pressure of 3.33 Pa, viz., 5.9 GPa and 105 GPa respectively. In contrast, all as-deposited Nb substituted TiN (Ti1-yNbyN) films crystallized into rock salt structure with (111) orientation up to y = 0.77. The hardness and Young%26apos;s modulus for Ti1-yNbyN films increased with increase in Nb concentration. The highest values of hardness and Young%26apos;s modulus obtained were 29 GPa and 320 GPa respectively. This study shows that nitrogen deficient titanium nitrides are more difficult to crystallize and exhibit lower hardness than metal substituted nitrides.

• 出版日期2013-9