VALVED CRACKER SOURCE FOR PHOSPHORUS : KPC SERIES The RIBER multi-zone phosphorus valved cracker source is dedicated to III-V base semiconductor MBE growth, desi- gned to procure loading capacity, beam flux levels, rapid flux adjustment/shut-off possibilities and cracking efficiency that meets the requirements of the production environ- ment. The cell consists of three main assemblies made of carefully selected materials which are chemically and heat-treated to provide state of the art flux purity. A vapor generator source-zone produces a stable vapor of tetrameric molecules through in-situ sequential or simul- taneous conversion to white phosphorus of part of the red phosphorus charge. The source-zone is connected to a valve that provides me- chanical means of instantaneously controlling the tetramic phosphorus vapor flux over several decades, while offering complete chamber isolation if reloading the source is requi- red. A cracker zone situated at the outlet of the source brings thermal means to crack the primary vapor to P2 molecules independently of the flux level, thus ensuring minimum di- rect white phosphorus formation inside the growth chamber and bringing an additional level of process control. The instrument is fully modular; any of the main assembly can be serviced or replaced independently of the others as simply as disconnecting a Conflat® flange. n Full modularity of the design for simple P charge n loading, maintenance or further upgrading n “Zero burst” patented design n Three-zone temperature concept n Fast and precise control over phosphorus flux n 100% leak tight all metal metering valve n Wide product range from 250cc to 2500 cc n Low condenser temperature to avoid Pwhite n instabilities KPC250
Transcript
ValVed CraCker sourCe for PhosPhorus : kPC serIes
The rIBer multi-zone phosphorus valved cracker source is
dedicated to III-V base semiconductor MBe growth, desi-
gned to procure loading capacity, beam flux levels, rapid
flux adjustment/shut-off possibilities and cracking efficiency
that meets the requirements of the production environ-
ment.
The cell consists of three main assemblies made of carefully
selected materials which are chemically and heat-treated
to provide state of the art flux purity.
a vapor generator source-zone produces a stable vapor
of tetrameric molecules through in-situ sequential or simul-
taneous conversion to white phosphorus of part of the red
phosphorus charge.
The source-zone is connected to a valve that provides me-
chanical means of instantaneously controlling the tetramic
phosphorus vapor flux over several decades, while offering
complete chamber isolation if reloading the source is requi-
red.
a cracker zone situated at the outlet of the source brings
thermal means to crack the primary vapor to P2 molecules
independently of the flux level, thus ensuring minimum di-
rect white phosphorus formation inside the growth chamber
and bringing an additional level of process control.
The instrument is fully modular; any of the main assembly
can be serviced or replaced independently of the others as
simply as disconnecting a Conflat® flange.
n full modularity of the design for simple P charge
n loading, maintenance or further upgrading
n “Zero burst” patented design
n Three-zone temperature concept
n fast and precise control over phosphorus flux
n 100% leak tight all metal metering valve
n Wide product range from 250cc to 2500 cc
n low condenser temperature to avoid Pwhite
n instabilities
kPC250
W o r k I N G P r I N C I P l e s
s P e C I f I C a T I o N s
a valve controller is strongly recommended
for kPC250 and kPC1200
schematic view of the kPC1200
requIreMeNTs
MulTi-valve ConTroller
NVC6000
Cracker power & T/C feedthrough
Cracker Transit tube
Valve heating mantel
Flux valve
Evaporator loading flange
Thermal enclosure
Condenser
kPC1200
Single-valve ConTroller
aVP504
The evaporator is placed inside the condenser and receives the
red phosphorus primary loaded charge. For an easy loading, the
evaporator heated crucible is mounted on an independent base
flange. after loading, the red phosphorus is heated to an evapo-
ration temperature to produce P4 that will condense into white
phosphorus. The condenser surrounds the red phosphorus and is
connected to the flux valve. an isolation valve vents and pumps
down the condenser during re-loading operations. P4 vapor
condenses on white phosphorus and the condenser wall and is
re-evaporated at a rate dependant upon the condenser tempe-
rature typically 60/100°C.
The condenser is set in a thermostatic enclosure allowing inde-
pendent temperature control of the condenser between 40 and
120°C.
The enclosure is heated with a fan assisted force air circulation and
temperature is monitored by a controller.
an all-metal valve is placed between the condenser and the
cracker stage. it is fully independent and can easily be serviced
or replaced. The micrometer driving mechanism enables fine ad-
justment and complete interruption of the phosphorus flux in the
cracker. The valve is fully leak tight in the closed position enabling
cell reloading without venting. The valve is externally heated by a
heated mantle to prevent white phosphorus condensation on the
valve mechanism.
The cracker stage is inserted inside the growth chamber and is
connected to the valve.
a high conductance transit tube allows the transfer of P4 mole-
cules to the cracking zone. The cracker stage design allows an
efficient dissociation of the P4 molecules into the cracking zone.
The cracker stage design allows an efficient association of the P4
molecules to dimmers. The cracker is heated by a flat Ta filament.
a wire thermocouple is used to monitor the cracker stage tempe-
rature.
an independent and optional water panel can be provided around
the cracker to limit the heat load in the growth chamber.
P red P whiteP4 P4 P2
evaporation
(T ≈ 300 - 350°C)
evaporator Condenser
Condensation
(T < 100°C)
evaporation
Cracking zone
Cracking
(T > 850°C)
sourCe Model CharaCTerIsTICs s40 kPC250 s63 kPC1200 s250 kPC2500
Filament 2 Flat foil
Heating filaments Wire
Crucible / valve material al203 / Stainless steel
usefull capacity (Max load dimensions) 250 cc 1200 cc 2500 cc
The production of phosphorus results in the formation of white phosphorus -
a material extremely toxic to humans.
under standard conditions cracker sources are built to limit any remaining white
phosphorus in the condenser. For operators to feel secure with phosphorus han-
dling, riber offers a complete service pack including a complete cleaning and
refurbishing of your phosphorus valved cracker cell at riber plant.
Please contact riber for more information
about our service pack offer.
s o u r C e s e l e C T I o N G u I d e
sysTeMs sourCe Model s40 kPC 250 s63 kPC 1200 s250 kPC 2500
rIBer
MBe 32
Compact 12
Compact 21
ePineaT
MBe 412 (4"/6")
MBe 49
MBe 6000
MBe 7000
VeeCo / VarIaN
gen ii
MoD gen ii
gen 930
gen 10
gen 20
gen 200
gen 2000
VG
v80
v90
v100
v150
oTher sysTeMs riber sources are also available for use on systems from eiko, anelva, ulvac, SvTa and DCa, as well as customs chambers. Contact riber for details.
ConTaCT riBer For More DeTailS
reCoMMenDeD kPC 2500
6083
0S72
–201
2- T
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T e C h N o l o G I C a l l e a d e r s h I P
W o r l d W I d e P r e s e N C e
Riber is the world leading supplier of MBe processing equipment and related services.
in total, 750 of our MBe systems have been installed with at least one system in each
of the 35 countries with which MBe is involved. This represents 75% of the global market.
Capitalizing on its 30 years of experience, the company’s core philosophy is to design systems
in close association with customers. riber has invented and designed major features which
are now found in all MBe systems.
riber plays a key role in the development of MBe technology, providing customers with solutions
