Plasmon ion-assisted deposition (PIAD) is a technique used in thin-film deposition processes, particularly in the production of optical coatings. This method combines two key processes: plasmon excitation and ion assistance, to enhance the properties of deposited thin films.
Here is a breakdown of the process:
Plasmon excitation: Plasmons are collective oscillations of free electrons in a metal. In PIAD, a metallic target material is bombarded with energetic particles, typically electrons or photons, to excite plasmons within the material. This excitation induces a resonant energy transfer from the incident particles to the electrons in the metal, leading to the generation of plasmons.
Ion assistance: Simultaneously, ions are typically generated through a separate ion source and directed towards the substrate where the thin film is being deposited. These ions assist in the deposition process by impacting the growing film, enhancing adhesion, density, and other film properties. They can also help to densify the film structure and improve its mechanical properties.
Thin-film deposition: During the PIAD process, the excited plasmons and assisted ions facilitate the deposition of thin films onto a substrate. The material from the target is evaporated or sputtered, forming a thin film on the substrate surface. The combined effects of plasmon excitation and ion assistance contribute to the deposition of films with desired optical, mechanical, and chemical properties.
PIAD offers several advantages over conventional thin film deposition techniques, including better control over film properties, improved adhesion, densification of films, and the ability to deposit complex multilayer structures with high precision. These properties make PIAD particularly useful in applications such as optical coatings for lenses, mirrors, filters, and other optical devices, where precise control over film properties is crucial for optimal performance.