MBE Components, Standard Effusion Cell WEZ

WEZ

Standard Effusion Cell

WEZ 40-10-22-KS
  • Applicable in most UHV systems up to 1400°C

  • Compatible with all standard MBE crucibles

  • Crucible capacities from 2 to 200 cm³

  • Most effective heating system with excellent reliability and long lifetime

  • Hot lip, cold lip and dual filament designs

  • Optional on-flange integrated cooling shroud and shutter

WEZ 40-10-22-KS Standard Effusion Cell with integrated cooling shroud and shutter on DN40CF (O.D. 2.75") flange, with 10 cm³ PBN crucible

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The Standard Effusion Cell WEZ is designed for evaporation or sublimation of a variety of elements and compounds, e.g., typical III-V MBE materials such as Al, Ga, or In, in the temperature range from 700°C up to 1400°C.
The WEZ is chiefly used for thin film growth and sample preparation, but may also be applied as a doping source (e.g. for Si or Be).

Standard filament SF, hot lip filament HL, cold lip filament CL and dual filament DF heaters are available, meeting differing requirements of the evaporation materials. 
Each filament assembly is built up of tantalum wires supported by PBN rings. This wire heater concept provides for excellent temperature uniformity within the crucible, an effective heating even at the crucible lip, and allows the use of differently shaped crucibles. Due to the few contact points between filament wire and supporting rings, decomposition of PBN at operation temperature is effectively minimized. Further advantages of the heater concept are its excellent reliability, long-term stability and extended lifetime, compared with Ta foil heaters.

In addition to the standard crucible material PBN (pyrolytic boron nitride), WEZ cells can also be equipped with PG (pyrolytic graphite), refractory metal, or Al2O3 crucibles.

WEZ wire heater

Schematic of the wire heating assembly

Application

WEZ standard effusion cells are usually employed in research type UHV systems for elements and compounds that require operation temperatures between c. 700°C and 1400°C. Typical evaporants are, amongst others, Ga, In, Al, Si, Be, Cu, Ag, Au, CaF2, etc.

The typical fields of application for WEZ cells are sample preparation, thin film growth and MBE. For instance, the compact design of the WEZ 40-10-22-KS makes it particularly suited to material deposition on small samples in surface analysis systems.
Cells tailored to the different evaporation material requirements are offered for MBE applications, e.g., hot lip or dual filament cells for Ga and In, or cold lip cells for Al. 

WEZ cells can also be used for doping applications. For this purpose effusion cells with conical crucibles are available. Please refer to DEZ Doping Effusion Cells.


WEZ 40-35-34-S close-up

WEZ 40-35-34-S-HL
, view onto hot lip filament

Technical Data

Filament type Ta wire heating filament: standard (SF), hot lip (HL), cold lip (CL), dual (DF)
Thermocouple W5%Re/W26%Re (type C)
Operating temperature 700-1400°C
Outgassing temperature max. 1500°C
Bakeout temperature 250°C
Cooling integrated water cooling or separate cooling shroud
Crucibles 2-200 cm³; PBN, PG, Al2O3 crucibles (other materials on request)
Options integrated water cooling (K), integrated rotary shutter (S)



Crucibles

In order to ensure compatibility with all MBE systems, WEZ cells are conveniently available with a wide range of standard crucibles of different shapes and sizes. Most of the crucibles are cylindrical, but conical shapes with taper angles up to 10° are available as well.
The most commonly used crucible material is PBN; other materials are available as required. Please refer to the Selection Guide or inquire for detailed recommendations. For information on crucibles see Crucibles.

The second number of the product code is the nominal crucible capacity [in cm³], the third number indicates the lip diameter of the crucible. Please specify crucible material, if not PBN.


Dimensions

Schematic drawing WEZ Schematic drawing of the Standard Effusion Cell WEZ

(drawing shows
WEZ 40-10-22-KS)



Specific data

For general information on CF mounting flanges see Flange and Gasket dimensions.

[cm³] [mm] Type Type [mm] / [mm] [W] / [A] Product code Product code
WEZ 16 - 2 - 16 - SF¹ - C - P - LxxxD16 155 / 8 PS 30-10 PBN 2-16
WEZ 40 - 2 - 16 - SF¹ - C - P - LxxxD34 120 / 7 PS 30-10 PBN 2-16
WEZ 40 - 2 - 16 - S - SF¹ - C - P - LxxxD34 160 / 8 PS 30-10 PBN 2-16
WEZ 40 - 2 - 16 - K S - SF¹ - C - P - LxxxD34 170 / 8 PS 15-10 PBN 2-16
WEZ 40 - 10 - 22 - S - SF² - C - P - LxxxD34 240 / 8 PS 30-10 PBN 10-22
WEZ 40 - 10 - 22 - K S - SF² - C - P - LxxxD36 240 / 9 PS 30-10 PBN 10-22
WEZ 40 - 25 - 33 - S - SF² - C - P - LxxxD33 450 / 14 PS 40-19 PBN 25-33
WEZ 40 - 35 - 34 - S - SF² - C - P - LxxxD34 470/ 12 PS 40-19 PBN 35-34
WEZ 40 - 12 - 37 - SF¹ - C - P - LxxxD37 465 / 15 PS 40-19 PBN C12-37
WEZ 40 - 35 - 37 - SF² - C - P - LxxxD37 495 / 14 PS 40-19 PBN 35-37
WEZ 40 - 60 - 37 - SF² - C - P - LxxxD37 580 / 11 PS 40-19 PBN 60-37
WEZ 63 - 35 - 34 - K S - SF² - C - P - LxxxD57 490 / 11 PS 40-19 PBN 35-34
WEZ 63 - 35 - 37 - S - SF² - C - P - LxxxD56 555/ 14 PS 40-19 PBN 35-37
WEZ 63 - 60 - 37 - S - SF² - C - P - LxxxD56 580 / 11 PS 40-19 PBN 60-37
WEZ 63 - 60 - 37 - K S - SF² - C - P - LxxxD57 600 / 11 PS 40-19 PBN 60-37
* rotary shutter possible on same flange      ¹ alternatively CL Note: max. Power/Current and Power supply are dependent on filament operating mode (SF, HL, Cl or DF)
** PBN standard, other materials on request ² alternatively CL, HL or DF
*** specify UHV length L with order


Product code:

e.g. WEZ 40-10-22-KS-HL-C-P-L220D36

is a standard effusion cell on DN40 CF-flange for a 10 cm³ crucible (lip Ø 22mm), with integrated water cooling shroud, shutter, hot lip filament, type C thermocouple, PBN crucible, in-vacuum length 220mm and diameter 36mm.