Thermal oxidation of reactively sputtered amorphous W80N20 films

Abstract

The oxidation behavior of reactively sputtered amorphous tungsten nitride of composition W 80 N 20 was investigated in dry and wet oxidizing ambient in the temperature range of 450 ·c-575 ·c. A single W0 3 oxide phase is observed. The growth of the oxide follows a parabolic time dependence which is attributed to a process controlled by the diffusivity of the oxidant in the oxide. The oxidation process is thermally activated with an activation energy of 2.5 ±0.05 eV for dry ambient and 2.35 ±0.05 eV for wet ambient. The pre-exponential factor of the reaction constant for dry ambient is 1.1 X 10 21 A 2 /min; that for wet ambient is only about lO times less and is equal to 1.3 X 10 20 A 2 /min.

Synthesis and characterization of tungsten oxide nanorods from chemical vapor deposition-grown tungsten film by low-temperature thermal annealing

“…The oxidation of W is thermodynamically favored and the formation of WO 3 is more favored than the formation of WO 2 . 27,59 The evaporation of WO 3 has been observed even at a low temperature of 550°C. 60 Thus in our growth temperature, WO 3 vapors readily evaporate into the gas phase.…”

Physical characterization of sputter-deposited amorphous tungsten oxynitride thin films

“…The focus of the present work is the synthesis and physical characterization of tungsten oxynitride films. Tungsten nitrides have been widely studied for their use as diffusion barriers in microelectronics [18][19][20], gate electrodes in semiconductor devices [21,22], hard coatings to protect from mechanical wear [23][24][25], or as Schottky contacts [27]. Several of the early studies have contributed extensively towards the understanding of W-N system, especially the knowledge of fundamental relationship between different parameters, such as deposition conditions and their effect on the internal stress, microstructure, and elemental concentration [18][19][20][21][22][23][24][25][26][27][28][29][30][31].…”

“…Tungsten nitrides have been widely studied for their use as diffusion barriers in microelectronics [18][19][20], gate electrodes in semiconductor devices [21,22], hard coatings to protect from mechanical wear [23][24][25], or as Schottky contacts [27]. Several of the early studies have contributed extensively towards the understanding of W-N system, especially the knowledge of fundamental relationship between different parameters, such as deposition conditions and their effect on the internal stress, microstructure, and elemental concentration [18][19][20][21][22][23][24][25][26][27][28][29][30][31]. Similarly, tungsten oxides have been studied for a wide variety of electrical, optical, and energy related applications [1][2][3][4][5][6][7][8][9][10][11][12] to longer wavelengths, and concluded that the conductivity of said films is lowered with increased nitrogen content [33].…”

Amorphous Ta-nanocrystalline RuOx diffusion barrier for lower electrode of high density memory devices

“…In the case of amorphous barriers, the fast diffusion of oxygen through the barrier layer can be retarded at high temperatures due to its lack of grain boundaries. 36 It has been reported that the surface of the Ta-Si-N, amorphous ternary compound barrier is oxidized. The polycrystalline barriers possess the grain boundaries, which can act as fast diffusion paths as well as nucleation sites in forming various oxides.…”