Influence of Al Content on the Properties of MgO Grown by Reactive Magnetron Sputtering

Abstract

In the present work, reactive magnetron sputtering in DC mode was used to grow complex oxide thin films, starting from two separate pure metal targets. A series of coatings was produced with a stoichiometry of the film ranging from MgO, over MgxAlyOz to Al2O3. The surface energy, crystallinity, hardness, refractive index, and surface roughness were investigated. A relationship between all properties studied and the Mg content of the samples was found. A critical compositional region for the Mg–Al–O system where all properties exhibit a change was noticed.

Sputter-deposited Mg–Al–O thin films: linking molecular dynamics simulations to experiments

“…The velocities of the O 2− ions are sampled from a Maxwellian distribution with the most probable energy of 0.025 eV (300 K) and random direction. The velocities of Mg 2+ and Al 3+ ions have values calculated from a Maxwellian distribution with the most probable energy of 1 eV and the direction at a certain angle to the plane normal to the surface (see figure 1), which corresponds to the position of the two metallic targets in the experiment [15]. The timestep is chosen to be variable and is calculated in the model in the order of 1-2 fs.…”

“…All depositions were performed in metallic mode [28]. The experimental procedure is described in more detail elsewhere [15].…”

“…Al 2 O 3 thin films have also been used as a buffer layer in order to improve the optical properties [7] and in various types of microelectronic devices as a dielectric, diffusion and/or tunnelling barrier [8][9][10]. There are few experimental studies on the structure and properties of MgO, MgAl 2 O 4 and Al 2 O 3 thin films deposited on Si or SiO 2 by different techniques [11][12][13][14][15]. In general, the MgO films were reported to have a crystalline structure with different orientations depending on the substrate temperature [11,13,15].…”

“…There are few experimental studies on the structure and properties of MgO, MgAl 2 O 4 and Al 2 O 3 thin films deposited on Si or SiO 2 by different techniques [11][12][13][14][15]. In general, the MgO films were reported to have a crystalline structure with different orientations depending on the substrate temperature [11,13,15]. The deposited MgAl 2 O 4 , and Al 2 O 3 films were characterized by an amorphous structure [12][13][14][15].…”

Texture and microstructure in co-sputtered Mg-M-O (M = Mg, Al, Cr, Ti, Zr, and Y) films

“…The magnetrons were fed by a PFG 1500 DC Hüttinger power supplies. More details on the experimental setup can be found in a previous report 28 . Films were deposited on RCA-cleaned Si (100) substrates covered by a ~2nm native SiO 2 layer.…”