Materials - Amorphous insulating layers

Amorphous insulating layers


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.



  • 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



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)

The cross section of MIS structure (Metal - Insulator - Semiconductor) using oxide insulating layer obtained at low temperature by the ALD method.

Cross sections (SEM) and scans (AFM) of surface with RMS roughness values ​​of insulating layers: HfO2, Al2O3/HfO2/Al2O3 and Al2O3.