A heated, frit-contained vapor source for low-vapor-pressure organometallic solids. It bolts to the chamber on a 2¾″ CF (DN40CF) and meters precursor vapor in through a small effusion orifice. Film growth or decomposition happens on the substrate in the main chamber.
- Mounting flange: 2¾″ CF (DN40CF)
- Differential pump port: 1.33″ CF (DN16CF)
- Side carrier-gas port
- Translatable doser snout, mount to a 275 single axis or 275 multi axis translator
- Cartridge heater and thermocouple on the source block
- Orifice typically 1–2 mm, other sizes available
Effusion, not a critical orifice
At this orifice size and at normal source pressures the aperture is an effusion limit. Throughput follows upstream vapor pressure and source temperature. The charge only has to reach a vapor pressure the molecule can survive, usually well below decomposition.
Solids stay in the source
Powder or crystals sit between a pair of fine sintered few-micrometer frits. Vapor passes. Particles are not entrained into the beam. Suitable for low-vapor-pressure solids such as Cu and Ag β-diketonates.
Carrier sweep, or pure effusion
A side port on the 2¾″ flange feeds a gas path along the heater block. Ar, N₂, or H₂ preheats on the block and is driven through the frit-held precursor, so the orifice sees carrier saturated with organometallic vapor. The same source runs with no carrier, as a pure effusive doser.
UHV at the chamber
The 1.33″ CF port is a differential pump port. It holds UHV on the chamber side of the internal source seals. Externally the assembly is a stainless nipple, knife-edge flange, side gas port, and compression fittings for the heater leads.
Bakeout rating is not confirmed here. It is set by the internal seal set and should be stated on the drawing before this page goes live.
Options
- Orifice diameter in the 1–2 mm range
- Snout stickout to suit the port length and sample distance
- Carrier-gas fittings