- Up to 1021 /ccm Boron doping in Si-MBE
- Evaporation of elemental Boron or Si-B alloy in vertical e-beam evaporator
- Small dimensions; can be used in DN63CF (O.D. 4.5“) effusion cell ports; hearth volume 5 cm³
- Long filament lifetime and easy maintenance
- 270° beam deflection
- High frequency x-y-beam deflection system
- Silicon shielding parts for use in SiGe-MBE Datasheet
Introduction
The Vertical Electron Beam Evaporator EBVV-B 63-5 allows to introduce real e-beam evaporation into your MBE system that has originally been designed for effusion cells only.
The unique and extremely compact design permits to install the EBVV-B 63 instead of an ordinary effusion cell on any MBE system having CF63 ports with an I.D. ≥ 60 mm. Even tilted ports can be used. Despite its small footprint, the new EBVV-B 63 includes a complete electromagnetic x- and y-dynamic beam deflection system and can deliver beam powers up to 3 kW.
The evaporator hearth volume is 5 cm³.
The 270° beam deflection design of the electron emitter eliminates nearly all ion bombardment on the filament due to a sharply bent electron beam path near the beam exit aperture. Thus, the filament is well shielded from evaporant or charged particles ejected from the crucible.
Application
The EBVV-B 63-5 allows high purity evaporation of elemental boron or Si-B alloy. Consequently, it allows Si and SiGe MBE growth of highest Boron doped epi-layers with Boron concentrations up to 1021/ccm.
This concept is applied in Si/SiGe HBTs or Si based Esaki-Diodes with record peak-to valley ratio and current density. The SIMS profile below shows a 275 nm Si layer with high Boron doping.
Silicon shielding parts
The EBVV-B is equipped with a specially adapted set of shielding parts manufactured from high-purity single crystalline Si. A Si plate and a ring cover all parts of the metallic body that are potentially subject to electron or ion bombardment and that face the substrate.
Only this Si-shielding allows the growth of highest purity Boron doped Si and SiGe films.
We also supply high purity Si-B source material in superior quality. It is machined and pre-conditioned from wafer-grade Si-single crystals and high purity Boron, fitting the evaporator hearth.
Technical Data
| Mounting Flange | DN63 CF (O.D.4,5“) or DN100 CF (O.D.6“) |
| In‑vacuum dimensions | L=234-400 mm; D=60 mm |
| Filament | short-legged coil of W wire, electron emitting filament |
| Operating pressure | 1×10-11 mbar - 1×10-5 mbar |
| Bakeout temperature | 200°C (all air side connectors removed) |
| Cooling / water cooling | water cooling, connectors SwagelokTM |
| Cooling water flow | 5 l/min at 4 bar |
| Crucibles | 5cm³ Ø 23 mm (12° taper) x 15 mm |
| Options | Tilted hearth (T); integrated rotary shutter (S) |
| Power | 4 - 6 kV max. 3 kW |
| Filament current | max. 25 A at 10V (AC) |
| Spot size | 5 mm diameter, approx. |
| Primary beam deflection | C270° by permanent magnet system |
| Dymamic beam deflection | coils wound from KAPTON® isolated wire x-deflection current: ± 1.5 A; y-deflection current: ± 2 A; deflection frequency: max. 150 Hz |
