Aluminium Dioxide (Al2O3) PLD Target

Alumina (Al2O3) is a PLD target material that is used to create thin films for a variety of applications. The colour of an Al2O3 sputtering target is typically very pure white and the films are highly transparent on deposition in thin film form.

Common Uses of Alumina (Al2O3) Thin Films

The most common use of Al2O3 thin films is as an electrical insulator. Al2O3 thin films are used as dielectric layers in capacitors and other electrical components due to their high dielectric constant and low electric conductivity. Al2O3 thin films are also used as diffusion barriers in multilayer integrated circuits to prevent inter-layer electrical shorts. Other applications for Al2O3 thin films include optical coatings for lenses and mirrors.

Typical Materials and Substrates Al2O3 is Deposited On

Epitaxial films of Al2O3 can be deposited on substrates such as sapphire, spinel, and yttria-stabilized zirconia (YSZ). The most common substrate used for this purpose sapphire (Al2O3) for homoepitaxy as it is readily available and relatively low cost. Additionally, the lattice parameter of sapphire is well-matched to that of Al2O3, which Other substrates, such as spinel (MgAl2O4), also exhibit good lattice matching and can be used for epitaxial film growth.

For the deposition of quality polycrystalline films of Al2O3, a variety of different substrates can be used, such as silicon, quartz, and silicon carbide. In addition, the use of particular substrates can impart additional properties to the deposited films, such as lower resistivity, higher optical transparency, or improved thermal conductivity. For instance, the deposition of Al2O3 on silicon can lead to films with lower resistivity, while deposition on quartz can result in films with improved optical transparency.

What are the Typical Properties of Al2O3 in Thin Film Form

Generally, Al2O3 thin films have a high dielectric constant, low electric and thermal conductivity, excellent corrosion resistance, high melting temperature, high hardness, high abrasion and oxidation resistance, Al2O3 thin films also have high thermal stability and can withstand temperatures up to 900°C.

What are the Typical Deposition Conditions for Al2O3 Thin Films by Pulsed Laser Deposition

To deposit Al2O3 thin films by PLD, a target material with a high purity level of Al2O3 is required. The typical deposition conditions for Al2O3 thin films by PLD include a substrate temperature between 300-800°C, a deposition pressure of 1-2 mbar, and a deposition power of 5-50 mJ/pulse. Smaller wavelength eximer lasers are preferred due to the large bandgap of Al2O3 - using 193 vs 248 nm will reduce droplet formation in the film do to lower thermal interaction with the laser and the target.