Beam Flux Monitor
Beam Flux Monitor
The Beam Flux Monitor (BFM) is designed to measure the beam equivalent pressure (BEP) of the atomic/molecular beam emitted by a source in a UHV process chamber.
The BFM is mounted just below substrate level so that the ionization gauge (IG) can be positioned directly beneath the substrate for measurement.
Application:
The BEP can be used to calibrate the flux for each source (e.g., effusion cell) and determine a suitable flux ratio for growth.
Product overview
The Beam Flux Monitor includes:
- Bayard-Alpert type nude ionization gauge head – with twin-tungsten filament for improved durability and thermal stability
- UHV sealed bellows assembly with linear motion,
- Stepper motor with mounting adapter and clutch (optional)
In the idle state the BFM may be retracted to the following positions:
- behind a tantalum shield
- behind the chamber cryopanel
- behind an isolation gate valve
The length of the linear motion is therefore dependent on the process chamber diameter and the idle position.
Special Add-on Feature
To maximise the system up-time and minimize disruption to growth campaigns, the BFM may be isolated vacuum-wise from the process chamber. This allows quick exchange the IG head without venting the main process chamber. Ideal for production systems and busy research labs!
Specifications
Mounting flange | DN63CF |
Linear travel (mm) | 150 – 500 mm |
Bakeout temperature | 200 °C |
Pressure sensitivity | 1E-4 … 5 E -11 Torr |
Filament | Tungsten (recommended) Thoriated iridium |
Motion Interlock | Position sensor included |
Motorized control | Optional (requires MCU-BFM) |
Gate valved isolation | Optional |