Investigation of zirconium oxynitride thin films deposited by reactive pulsed magnetron sputtering

Abstract

Zirconium oxynitride films were deposited onto glass and Si (1 0 0) substrates at room temperature by pulsed reactive dc magnetron sputtering of a metallic Zr target in an Ar/O2/N2 atmosphere. The structural, compositional and optical properties of the deposited films were found to depend on the ratio of nitrogen partial pressure to the total reactive gas partial pressure. Morphology investigation by atomic force microscopy showed that most of the zirconium oxynitride coatings have smooth surfaces (average roughness 2.5 nm). X-ray diffraction measurements revealed a change from the monoclinic zirconium oxide phase to the orthorhombic, and then a change to the cubic zirconium nitride phase upon changing the nitrogen content in the films. Optical properties of zirconium oxynitride films were analysed by a spectrophotometer and computer simulations. The calculated refractive index of transparent and semi-transparent films was found to be in the range 2.05–4.73 (at 650 nm). The optical band gap changed from 3.67 to 1.59 eV with changing nitrogen content. This study allows the elaboration process optimization and then the control of the film composition and properties, which is very interesting for a technological transfer.

Combining reactive sputtering and rapid thermal processing for synthesis and discovery of metal oxynitrides

“…The variation of deposition rate as a function of O 2 and N 2 PPs has been used to guide oxynitride film synthesis. 21,26 However, deposition rate profiles in the presence of both O 2 and N 2 are not always easily interpreted due to several phenomena, such as competing metal-nitride and metal-oxide poisoning, varying sputtering rates of different metal-nitrides and corresponding variation in the sputter voltage. 27 In such cases, a simple, heuristic identification of optimal O 2 PP for oxynitride synthesis is the O 2 PP at the onset of target poisoning, as observed from deposition rate profile in Ar-O 2 mixtures.…”

“…For N 2 PPs sufficient to introduce significant nitrogen into the films, N/O stoichiometry varies nonlinearly as a function of the ratio of N 2 and O 2 gas flow rates, highlighting the importance of careful control and calibration of the reaction gas atmosphere. 20,21,[25][26][27][28][29] Using a variable leak valve to control O 2 PP, we demonstrate the ability to carefully control O 2 PPs and fine-tune oxynitride chemistries. We further discuss a heuristic approach to rapidly obtain the optimal O 2 PP for depositing oxynitride films.…”

“…20,21,23,25,27 While oxynitride phases have been observed in the as-deposited films in some cases, 26,30,31 several factors such as total pressure, power, and substrate temperature during sputtering are likely to simultaneously control both the composition and crystal structure of the as-deposited oxynitride chemistries. To decouple the temperature-dependent reactivity of the growing film in sputter atmosphere and thermally activated crystallization, we demonstrate RTP as postdeposition, iso-compositional crystallization process that provides access to high-temperature phases without compromising anion stoichiometry.…”

Nitretação a plasma de zircônia estabilizada com ítria: um estudo comparativo

“…A nitretação da zircônia é realizada essencialmente por substituição parcial ou total dos íons de O por íons de N, o qual é responsável pela excelente adesão entre a camada nitretada e o substrato [9,23,24]. O composto obtido pela nitretação da superfície de zircônia encontra aplicações relevantes como revestimento protetor de ferramentas de corte e matrizes [15,18], como barreira de difusão e como contato elétrico em circuitos integrados [16] e também como revestimentos decorativos [25,26]. Neste último, a formação de oxinitreto de zircônio ZrO x N y na região próxima à superfície da zircônia nitretada tem sido investigada, explorando o fato de que a concentração de oxigênio na camada superficial controla a cor [21].…”

Dureza e resistência ao desgaste da camada de ZrN formada por nitretação a plasma sobre zircônia parcialmente estabilizada com ítria

“…Finalmente, devido a sua grande afinidade por oxigênio [8,30], o ZrN adere muito bem à maioria dos substratos, devido à formação de oxinitreto de zircônio (ZrN x O y ) na interface. O compósito formado pela deposição de filmes finos de ZrN, ou pela formação de ZrN na superfície da zircônia por nitretação tem muitas aplicações [25,26], como revestimento protetor de ferramentas de corte e em moldes, como barreira a difusão, como contatos elétricos e, não menos importante, como revestimento decorativo [31,32]. ZrN tem cor dourada [15,33,34], mas é a possibilidade de controlar a cor do revestimento, mediante a deposição controlada de oxinitreto de zircônio que tem especial interesse para revestimentos decorativos, pois a razão O/N no filme determina a sua cor [26,33].…”