Tungsten evaporation boat

molybdenumtantalumfor thermal evaporation

Overview
We manufacture evaporation boats in tungsten (W), molybdenum (Mo), molybdenum‑lanthanum (ML), molybdenum‑yttrium oxide (MY) and tantalum (Ta) for resistance (thermal) evaporation. When current is applied the boats heat the coating material to evaporation temperature. The low vapor pressures of the boat materials prevent boat material entering the vapor and the deposited layer, ensuring high layer purity and long boat service life.

Vacuum evaporation process
The thermal vacuum evaporation process (resistance evaporation) is a PVD technique in which the coating material is heated inside a vacuum chamber until it evaporates and condenses on substrates. Typical deposited materials include Al, Ag, Cr, TiN, SiO2 and others. Selection of boat material and geometry directly impacts process stability, contamination and lifetime.

Your advantages at a glance

• Very low vapor pressure of boat materials — minimal contamination
• High corrosion resistance in contact with molten coating materials
• Good electrical conductivity for resistance heating
• Very high melting points and dimensional stability at process temperatures
• Available geometries for process optimization: straight, step, non‑splash

Standard product range / materials
We supply boats in tungsten, molybdenum (including ML and MY variants) and tantalum. Tungsten delivers the highest melting point and excellent corrosion resistance; dopants such as potassium silicate improve corrosion resistance and dimensional stability. Molybdenum is dimensionally stable at high temperatures; La2O3 (ML) increases ductility and corrosion resistance, Y2O3 (MY) improves machinability. Tantalum features extremely low vapor pressure and outstanding corrosion resistance.

Types / geometries

• Straight type – straight boats
• Step type – boats with a step between the clamping part and upper part
• Non‑splash type – boats with wings or a cover to minimize splashes

Table — suitable boat materials for coating materials (overview)
Compatibility of W, Mo (ML/MY) and Ta boats with common coating materials is indicated in the compatibility table. Symbols: + suitable, ++ recommended. Exact selection depends on process temperature, vapor pressure and evaporation cycles; consult the compatibility table or our application engineers for material‑specific guidance.

Notes
Selection must consider coating material density, melting and boiling points, evaporation rate and process parameters. Boats marked suitable/recommended in the compatibility data represent typical recommendations; final choice should be validated under actual process conditions.

Characteristics / technical specifications

• Boat materials: W, Mo, ML, MY, Ta
• Low vapor pressure of boat materials → no boat contamination of layers
• Corrosion‑resistant materials; dopants (e.g., potassium silicate for W, La2O3 or Y2O3 for Mo) improve corrosion resistance and ductility
• Good electrical conductivity suitable for resistance evaporation
• Very high melting points and dimensional stability at evaporation temperatures
• Available geometries: straight, step‑type, non‑splash
• Crucible inserts and filaments for electron beam and resistance evaporation available; geometry and material can be optimized to the process
• Standard dimensions and item numbers available in the online shop; custom geometries on request