Correlation between the oxygen content and the morphology of AlN films grown by r.f. magnetron sputtering

Abstract

a b s t r a c tTo understand the influence of the oxygen on the crystallography of AlN thin films made by physical vapour deposition r.f. magnetron, three different oxygen content AlN films were prepared at room temperature for two values of the energy of the species building the film (low energy obtained by using: low power W, high pressure P; high energy obtained by using: high W, low P). It is observed that the crystalline morphology of the films not only depends on the process parameters (W and P), but is also particularly related to the oxygen content in the films. Regardless of P and W used here, low oxygen content films (5 at%) are columnar. The increase in oxygen content (15-30 at%) reduces the grain size without creating phases like Al 2 O 3 or AlNO, and very rich oxygen films (50 at%) are amorphous. From this study, assumptions are made for the localization of oxygen atoms in the AlN phase.

Low Vacuum Deposition of Aluminum Nitride Thin Films by Sputtering

“…All the obtained AlN films, even under the low vacuum environment, possessed the oxygen content much lower than the reported limit (30 at.%). The films prepared with the N 2 /Ar ratio of 0.26 exhibited the lowest oxygen content (4.1 at.%) that falls into the low oxygen content regime (≤5 at.%) of the films prepared by the conventionally used deposition technique under high‐vacuum base pressures …”

“…Although very few studies focused on the stoichiometry of the AlN films, the oxygen content has been investigated to some extent. Brien and Pigeat reported that the oxygen content of the films could reach about 30 at.% while maintaining the AlN würtzite structure. All the obtained AlN films, even under the low vacuum environment, possessed the oxygen content much lower than the reported limit (30 at.%).…”

“…Conventionally making such nitride films, similar to other nitride thin films, requires a low base pressure (high vacuum) before sputtering to minimize the influences of residual gases that may cause the formation of oxide or oxynitride overlayers. The introduction of oxygen atoms inside AlN may modify significantly its thermoconductivity, optical and electrical properties . Nevertheless, achieving the low base pressure is rather time consuming.…”

Влияние Концентрации Кислорода В Составе Газовой Плазмообразующей Смеси На Оптические И Структурные Свойства Пленок Нитрида Алюминия

“…Выбор методов синтеза пленок AlN определяется тре-бованиями технологии приборных структур, в частности: тонкие пленки AlN (до 1 мкм) возможно синтезировать методами молекулярно-пучковой эпитаксии [7][8][9], хими-ческого осаждения из газовой (паровой) фазы [7,10,11], нитридизации поверхностных слоев [12][13][14][15], реактив-ного ионно-плазменого или магнетронного осажде-ния [7,[16][17][18][19]. Процесс синтеза пленок нитрида алю-миния методом молекулярной-пучковой эпитаксии яв-ляется нетривиальным и дорогостоящим.…”

Electrical properties and memory applications of Al-rich Al-based dielectric thin films

“…The synthesis of AIOxN y films has been commonly reported using physical vapor deposition, such as ion-beamassisted evaporation and sputtering method [166,167,169,171]. As shown in some studies [170,173]…”