ELECTRON BEAM EVAPORATION

How does E-Beam evaporation work?

The process begins with the source material placed inside a water-cooled crucible. A filament beneath the crucible is heated, and a high voltage draws electrons from the filament, forming a focused beam. Bending magnets direct and sweep the beam across the surface of the source material, ensuring even heating and consistent evaporation.

Because the electron beam targets only the source material – not the crucible itself -contamination levels are significantly lower than in thermal evaporation processes.

Typical applications of e-beam deposition

Electron beam evaporation is used across semiconductor fabrication, optics, and advanced materials research where precise, high-purity thin film deposition is required.

Semiconductor fabrication

The process is widely used for depositing metal contacts, gate electrodes, and barrier layers on silicon wafers. Its excellent directionality makes it the standard method for lift-off patterning in MEMS and microelectronics — the evaporated flux has minimal sidewall coverage, allowing clean resist removal after deposition.

Optical coatings

High-quality anti-reflection coatings, mirrors, and bandpass filters are produced by depositing alternating layers of high- and low-refractive-index materials such as TiO₂ and SiO₂. The low defect density achievable with e-beam evaporation is critical for optical performance.

Research and advanced materials

Universities and research institutes use e-beam evaporation to develop novel thin film materials, explore surface functionalisation, and fabricate prototype devices. The process is compatible with a wide range of substrates, including wafers, glass, ceramics, and polymer films.

Key advantages of electron beam evaporation

E-beam evaporation offers several benefits over conventional thermal evaporation:

• Higher energy input – The concentrated electron beam delivers more energy into the source material, resulting in a denser film with stronger adhesion to the substrate.
• Lower crucible contamination – Only the source material is heated, keeping the crucible cool and reducing unwanted contamination in the deposited film.
• Excellent directionality – The evaporated material follows a well-defined flux path, minimising sidewall coverage. This makes e-beam evaporation the preferred method for lift-off processes.
• Multi-material deposition – Using a multiple-crucible e-beam gun, several different materials can be deposited in sequence without breaking vacuum.

For your lift off processes, consider choosing our Flextura Evaporator Module, either as a stand alone module, or in combination with a Flextura Cluster for high volume production.