Thermal sublimation of silicon from high purity intrinsic or highly doped Si filament
Excellent growth of thin silicon layers
Compatible with most MBE systems
Water-cooled electrical contacts
Inner filament shielding with pure silicon parts
No ceramic parts in the hot zone
The Silicon Sublimation Doping Source SUSI-D was developed for growing thin Si layers, short period Si/Ge superlattices and Si/SiGe heterostructures. It allows for growth of thin epitaxial Si layers with a crystal quality not otherwise possible by evaporation from effusion cell crucibles.
Main parts of the SUSI-D assembly
The most remarkable feature of the SUSI-D is its arch-shaped, free-standing silicon filament, which is directly heated by electrical current and exclusively surrounded by silicon shielding parts of highest purity, effectively shielding the hot filament.
High purity SUSI-D silicon parts:
filament arch, base plate, shielding tube,
The SUSI-D is used for Si epitaxy (especially growth of high quality thin Si layers), Si doping in III-V MBE and doping in Si MBE.
Operation and Results
The figure on the right compares the growth rates of SUSI 40 and SUSI 63, measured as a function of the electrical current through a new silicon filament.
Over the operation time the filament becomes thinner, whereby the growth rates at a given current gradually increases. The current settings should therefore be reduced from time to time to keep the flux rate constant.
|SUSI silicon growth rate as a function of the electrical current
|The next figure shows the RHEED oscillations measured during Si homoepitaxy on a (001) oriented silicon substrate at 20keV electron energy and a substrate temperature of 400°C.
From the RHEED oscillation diagram a growth rate of 1.22 monolayers per minute (1.66 Å/min) can be determined. The low decay of the oscillation amplitude indicates ultra pure growth conditions.
RHEED oscillations measured during Si homoepitaxy with a SUSI-D
Several publications base on samples grown with SUSI-D sources. Please have a look at section References / List of Publications.
|high purity monocrystalline silicon filament ρ>1000 Ω*cm (highly doped silicon on request)
|filament completely shielded with silicon parts
|W5%Re/W26Re (type C)
|max. filament temperature 1400°C (limited by Si melting point)
|water-cooled (4x Swagelok fitting connection O.D. 6mm); water flow min. 30 l/h
|separate water (or LN2) cooling shroud
|integrated rotary shutter (S)
|Schematic drawing of the Silicon Sublimation Doping Source SUSI-D
(drawing shows SUSI-D 63-S)
For general information on CF mounting flanges see Flange and Gasket dimensions.
|[mm] / [mm]
|[W] / [A]
|250 / 55
|500 / 80
|rotary shutter possible on same flange
|maximum growth rate at 100m distance
|specify UHV length L with order
e.g. SUSI-D 63-S-L310D56
is a silicon sublimation doping source on DN63 CF-flange with shutter, in-vacuum length 310 mm and diameter 55 mm.
The following list provides suggestions for related products. For additional product suggestions or more detailed information, please contact us.
|Silicon Sublimation Source
|Standard Effusion Cell
|Vertical Electron Beam Evaporator
|Cooling Shrouds CS
|Quartz Crystal Monitor QCM