Amorphous insulating layers

Description

Insulating thin films are obtained by atomic layer deposition (ALD) on different substrates: like Si, GaN, SiC, graphene, ZnO. Materials are formed in a double exchange chemical  reaction between two reactants (precursors), such as an oxygen precursor and a metal precursor. Insulating layers can consist of one or more oxide materials. The compounds can be grown at low temperatures, usually below 100°C. The maximum size of the substrate is 20 cm of a diameter.

Specification

• Materials: Al₂O₃, TiO₂, HfO₂, ZrO₂ and composite layers
• Thickness: 10 - 400 nm
• Growth controll in the nanometer scale
• Growth rate: 0.1 - 0.2 nm/minute
• Resistivity: >10⁸Ωcm
• Leakage current (1V): > 10^-7 A/cm²
• Dielectric strength: > 4 MV/cm
• Surface roughness: 0.2 nm < RMS < 10 nm
• Energy gap: > 3 eV
• Relative permittivity: 9 - 40
• Structure: amorphous layers
• Average transmission in visible spectra:> 80%
• Uniformity of coatings

Applications

Deposition of dielectric layers at a low temperature, below 100 ˚ C enables the construction of electronic devices  containing insulators in the interaction with different semiconductor materials such as Si, GaAs, ZnO, SiC, GaN, GaMnAs or graphene . Our studies show that the most efficient insulator is a composite layer. The combination of low temperature manufacturing and transparency of oxide layers causes that electronic devices with these materials, grown by the ALD technique, are a solid, viable, safe for the environment, and a very promising proposal for the next generation of transparent and flexible electronics.

Patent:  PL395639 (13-07- 2011)