Aluminum Fluoride Granules

AlF3, 99.999% pure, 1 - 4 mm

 

Aluminum Fluoride Pellets (AlF₃) are high-purity materials widely utilized in the production of thin films, optics, and advanced coatings. Aluminum fluoride is a low refractive index material especially suited for coatings in the UV, but also in the VIS and IR spectral range. Aluminum fluoride, in granular  form, is particularly suitable for Physical Vapor Deposition (PVD) processes.

 

AlF₃ is known for excellent thermal stability, low refractive index, and strong chemical resistance.

 

APPLICATIONS:

  • Thin-Film Deposition: Used in Physical Vapor Deposition processes to create thin films and coatings for optical, electronic, and protective applications.
  • Optical Coatings: Used in anti-reflective (AR) coatings due to its low refractive index, this will increase the performance of lenses, mirrors, and optical systems.
  • Metallurgical Flux: AlF3 serves as a flux in aluminum smelting, which aids in the removal of impurities and improves the efficiency of the processes.

APPLICATIONS:

  • Thin-Film Deposition: Used in Physical Vapor Deposition processes to create thin films and coatings for optical, electronic, and protective applications.
  • Optical Coatings: Used in anti-reflective (AR) coatings due to its low refractive index, this will increase the performance of lenses, mirrors, and optical systems.
  • Metallurgical Flux: AlF3 serves as a flux in aluminum smelting, which aids in the removal of impurities and improves the efficiency of the processes.

 

AR and HR coatings for laser optics in the VUV and DUV (e.g. at excimer wavelengths 157 nm, 193 nm, 222 nm …)

 

THIN FILM PROPERTIES:

Range of transparency      150 nm – 10 µm

Refractive index at

                      • 220 nm       ~ 1.39 – 1.41

                      • 550 nm       ~ 1.36

                      • 3 µm            ~ 1.28 – 1.30

Absorption edge                  ~ 150 nm

Thin film stress Tensile      (low)

NOTES FOR EVAPORATION:

  Evaporator source:                  Preferred: resistance heater thermal evaporation Electron beam Evaporator

   Liner / boat:                            Mo or Ta boat Copper crucible

   Evaporation temperature:    800 - 1000°C

   Deposition rate:                      1.0 - 2.0 nm/s

   Substrate temperature:        30 - 350°C, pref. 250 - 350°C

   QCR-settings:                         Density 2.88 g/cm³, z-ratio 1.0

   

AlF3 thin films show an amorphous structure. They exhibit reduced thin film stress and lower surface roughness compared to MgF2.

E-beam evaporation of AlF3 is possible, but usually avoided, due to the tendency of AlF3 to show stronger spitting compared to MgF2 and the other UV fluorides. Evaporation from a baffled box is recommended to achieve low defect densities. A substrate temperature in the range of 250 to 350°C is required for dense film structures.