Thin Film Deposition Systems

Thin film deposition refers to any technique where a very thin film of material, usually only a few atoms thick, covers a particular substrate. What makes this process attractive is the versatility and range of both the coating and target material, which allows the coating to improve or alter the substrate’s performance. Common applications include making the substrate scratch-resistant, making it more or less electrically conductive, or improving on a substrate’s durability.

The two primary methods of thin film deposition systems rely on either a physical evaporation process or chemical reactions to atomise the source material before bonding it to the substrate layer by layer. Physical processes rely on very low pressures on a resistive heat source to produce the required vapour pressure, while chemical processes use reactive gas and another precursor gas. When the two gases interact on the substrate, a chemical reaction occurs that results in an even film without the need for spin coating methods that may influence thickness or purity.

Thin film deposition techniques fall into two broad categories: physical vapour deposition (PVD) and chemical vapour deposition (CVD).

Physical Vapour Deposition (PVD)

PVD relies on mechanical, electromechanical, or thermodynamic processes to coat the target material with the atomised film. The most common technique involves vaporising a solid material in a high-vacuum deposition chamber and then depositing that material onto a substrate material. Physical deposition produces a highly durable, corrosion-resistant film that changes the properties of the substrate. Vapourisation methods include:

• Evaporation, such as electron beam evaporation, ion-assisted deposition (IAD), and thermal evaporation
• Magnetron sputtering
• Reactive sputtering
• Ion beam sputtering (IBS)
• Pulsed laser deposition (PLD)

Chemical Vapour Deposition (CVD)

CVD relies on volatile precursor chemicals in the gas phase to create a chemical reaction that results in a thin layer of deposited film on the substrate surface. Standard methods for chemical deposition include:

• Atmospheric pressure CVD
• Low-pressure CVD
• Ultra-high vacuum CVD
• Atomic layer deposition
• Plasma-enhanced CVD

Thin films allow manufacturers to change or enhance the properties of the substrate. The evaporated material may provide additional durability or confer a new property on the substrate, such as conductivity.

The main advantage of thin metal films is their versatility. Thin-film applications can vary in film thickness (ranging from one atomic layer to multiple layers), coating material (organic compounds, pure metal and almost anything in between), and substrates (ranging from a silicon wafer up to solar panels and biomedical implants).

Thin films are critical to:

• Opto-electronics such as consumer electronic devices, optical filters, and LED displays
• Precision optics such as focal plane arrays and anti-reflectivity/high reflectivity coatings
• Semiconductors such as photodetectors, RF power transistors, focal plane arrays and LEDs
• Medical applications such as biocompatible hard coatings for implants
• Decorative coatings for ceramics and cutlery

Many bench-top thin film deposition systems are solid-state instruments that offer limited functionality. The HEX series is unique amongst thin film deposition systems due to its versatility — its modular design allows for customisation and robust user control features. Not only does this make the HEX ideal for teaching about various thin film techniques, but it also allows research and production facilities to incorporate the latest advancements in thin films into their bench-top system.

Please contact us at Korvus Technology or download our brochure here for more information.