General Principle of ALD
Atomic Layer Deposition (ALD)

Atomic Layer Deposition (ALD) has its origins in Soviet research from the 1960s, when S. I. Koltsov and V. B. Aleskovsky developed the concept of Molecular Layering (ML), based on successive, self-limiting surface reactions.

Independently, in the 1970s, T. Suntola and his team in Finland developed a similar process, Atomic Layer Epitaxy (ALE), for the fabrication of ZnS-based electroluminescent panels. This principle, which involves depositing material one atomic layer at a time, allows for unprecedented control over the thickness and quality of the films, paving the way for industrial applications.

In the 1980s and 1990s, ALD gradually gained traction in microelectronics, particularly for III-V semiconductors, and later for the manufacture of high-density integrated circuits. The integration of ALD steps into industrial processes—for example,...