Sapphire Surfaces

Heating c-plane sapphire to a temperature of 1700 °C results in a perfect surface for subsequent epitaxy. These surfaces are characterized by atomically flat double-stepped terraces with widths exceeding 1 μm. The atoms on the surface rearrange in a singular in-plane orientation of the (√31x√31)R9° surface reconstruction, as shown in the reflection high-energy electron diffraction (RHEED) image on the right. The observation of up to 20 Laue circles indicates the high crystal quality of the surface.

Evaporation of All Elements

We have explored the deposition of elemental metal films with TLE. So far we have succeeded in depositing films with thicknesses ranging from 1 to 500 nm on 2 inch Si wafers. All elemental sources could be evaporated in the same setup with growth rates between 0.01 and 1 Å/s by varying the laser power. Due to the inherent efficiency of the TLE process, significantly less power is required compared to high-temperature effusion cells and e-beam evaporators. A set of sample examples is shown below. The films are dense and homogeneous and have a very smooth surface morphology. These results show that laser evaporation is well-suited for the growth of complex compounds with excellent control.

 

TLE publications


An overview of the key scientific publications about thermal laser epitaxy.
1The very first TLE paper
Description of the principle method and key features of the technology.
2019-05 / AIP Advances 9: Film deposition by thermal laser evaporation
2Substrate surface preparation
Description of the advantages of our THERMALAS substrate heater for surface termination.
2020-03 / APL Materials 8: In situ thermal preparation of oxide surfaces
3The TLE periodic table
Demonstration of thin film growth with 43 elements from the periodic table.
2021-02 / Journal of Laser Applications 33: Thermal laser evaporation of elements from across the periodic table
4Oxide evaporation
5Oxide epitaxy
Demonstration of epitaxial growth of metal oxide films NiO, VO2, and RuO2 on Al2O3 or MgO substrates.
2021-08 / Journal of Vacuum Science & Technology A 39: Epitaxial film growth by thermal laser evaporation
7Metal sources in oxygen
A systematic, experimental study of the role of source oxidation on source evaporation.
2022-12 / Journal of Applied Physics 132: Thermal laser evaporation of elemental metal sources in oxygen
8Nanostructure self-assembly
Self-assembly of nanocrystalline oxide structures enabled by our THERMALAS substrate heating system.
2023-01 / Advanced Materials 35: Self-Assembly of Nanocrystalline Structures from Freestanding Oxide Membranes
9Aluminum sources
10Evaporation of carbon
The effectiveness of TLE in synthesizing a broad spectrum of carbon films.
2023-10 / Crystal Growth and Design 23: Thermal Laser Epitaxy of Carbon Films