Chemical vapor deposition

From LNF Wiki
Jump to navigation Jump to search

Chemical vapor deposition is...

Chemical Vapor Deposition (CVD) is used to deposit solid material onto a substrate. This involves the reaction or decomposition of one or more precursor gases in a chamber containing one or more heated objects to be coated. The reactions occur on and near the hot surfaces, resulting in the deposition of a thin film on the surface. The chemical by-products or unreacted gases are then eliminated from the reactor chamber via the exhausting system. CVD must take place under vacuum to avoid the inclusion in the film, or creation of side products from the reaction of the ambient components with the precursor gases.


Technologies

The LNF has the following CVD techniques available.

Atomic Layer Deposition (ALD)

Main article: Technology 1

Describe the technology, particularly including why you might use it over another within the same group.

Low-Pressure Chemical Vapor Deposition (LPCVD)

Low pressure chemical vapor deposition uses heat to initiate a reaction of a precursor gas(s) on the substrate surface. This reaction at the surface is what forms the solid phase material. Low pressure is used to decrease any unwanted gas phase reactions, and also increases the uniformity across the substrate.

Parylene deposition

Is this PVD (as the title claims) or LPCVD, or something else?

Parylene deposition (PVD) is a method for depositing parylene, a thin, transparent polymer coating that is conformal, usually pinhole free, has high dielectric strength, high surface and volume resistivity, and resists moisture, acids, alkalis, petroleum products and solvents. Parylene is also “body safe” which means it can be used to protect medical devices and implantable electronics.

Plasma Enhanced Chemical Vapor Deposition (PECVD)

Plasma Enhanced Chemical Vapor Deposition (PECVD) is a technology that utilizes a plasma to provide some of the energy for the deposition reaction to take place. This provides an advantage of lower temperature processing compared with purely thermal processing methods like low pressure chemical vapor deposition (LPCVD). PECVD processing temperatures range between 200-400°C. LPCVD processes range between 425-900°C.

Figures of Merit

What is important to look for in the technology? Etch/dep rate? Resolution?

Refractive Index

Buffered HF (BHF) Etch Rate

Pinholes/Area

Applications

How is this technology used in nanofabrication and what types of devices/research areas is it useful in?

Chemical Vapor Deposition is used for depositing thin layers of material. Frequently these are insulating/dielectric layers. They can range from single atomic layers to a few microns thick depending on the technology used. Some Atomic Layer Deposition (ALD) systems can deposit metals, the LNF system deposits Al2O3, and HfO.

Equipment

Do we want a list of equipment here or keep those one layer down on the LPCVD, ALD, and Parylene page?


See also

Other related wiki pages

References


Further reading

  • Other stuff, e.g. technology workshop slides
  • External links (can be in another section below, if appropriate)