Depositionsextakte

Depositionsextakte is a term used in thin-film fabrication to describe a six-step deposition cycle in which six successive layers are deposited in a controlled sequence within a single cycle. The term combines 'deposition' with the German word for six-takt (six-phase cycle), and is encountered mainly in specialized European literature and in discussions of multilayer coating schemes.

In practice, a depositionsextakte typically comprises six distinct steps that may alternate materials, compositions, thicknesses, or surface treatments. A cycle may end with a conditioning step such as annealing, surface cleaning, or smoothing before repeating to build a multilayer stack. The exact order and materials are chosen to achieve specific optical, electronic, or mechanical properties.

Common deposition technologies used for sextakte sequences include physical vapor deposition (PVD), chemical vapor deposition (CVD), and atomic layer deposition (ALD). In situ metrology, such as quartz crystal microbalance, spectroscopic ellipsometry, or RHEED, is often employed to monitor thickness and interface quality.

Applications include optical coatings with tailored reflectance or transmittance, Bragg mirrors, diffusion barriers, and multilayer sensors. The approach allows fine control over interfacial roughness and strain by distributing the deposition burden across six steps rather than a single thick layer.

Challenges involve alignment of materials with different growth modes, interdiffusion at interfaces, process complexity, and longer cycle times. Standard terminology remains inconsistent, and the concept is not universally adopted; some authors refer to six-step deposition sequences as a generalized class within multilayer deposition rather than a distinct technique.