КОМЕФ Оборудование для заводских лабораторий,
приборы для научных исследований
Телефон/факс: (495) 916-1173 / 916-1594 / 916-1867. E-mail:
Адрес: 105120, Москва, Наставнический пер., дом 6, ООО "КОМЕФ"

New Products

It is time to solve your Aluminum evaporation problems :

The use of ammonia as a nitrogen precursor to grow Aluminum Nitrides and AlGaN by MBE is a very promising and powerful technique for QDs and MQWs. Conventional, Standard and even "Cold Lip effect" effusion cells are not adapted to work in an ammonia or Nitrogen gas environment. Ammonia or N reacts with Aluminum at the crucible mouth and produces nitride compounds. This induces a creeping of the Aluminum melt. Overflow of the molten charge is then observed. This phenomenon occurs quickly and prevents use of a conventional aluminum cell for more than a few runs. Several groups reported aluminum crucible breakage and cell disintegration under these conditions.

ADDON has designed a completely new high thermal gradient cell specially adapted to work in an ammonia atmosphere which would normally preclude Aluminum cell temperature idling because without cryocooling the system pressure could increase to more than 10-2 torr. A very good day to day reproducibility of Al flux versus cell temperature is possible.

Developed to cure the Aluminum cell problems when growing nitrides, this cell is superior to a "cold lip" type cell for non-nitride growth and makes Al use easier than ever.

Main advantages

  • Prevents the formation of very low vapor pressure aluminum nitrides on the crucible walls
  • Stongly negative temperature gradient
  • Very long term flux stability and excellent day-to-day reproducibility
  • Two independently heated and cooled zones
  • Easy to install on all MBE systems (several models available)
  • Only one power supply
  • Uses the well known low cost PBN crucibles
  • Increases the useful capacity of Al cells
RT luminescence of GaN/AlN QDs of varying sizes obtained under HeCd (325 nm) laser excitation
(the power density is 300 mW/cm
2 and the spot size is 1.5x2 mm2).
The white spot is combining four other spots of suitable size, color and intensity.
New Al Cell
Courtesy of Jean Massies – Nicolas Grandjean.CHREA CNRS Rue B Gregory Sophia Antipolis , 06560 Valbonne, France

Please ask for other references on the work conducted with Addon Al cells
For product information see HOT ZONE/COLD ZONE Al Cell

ZnO the best promises compound semiconductor of the new millenium?

ZnO exhibits a unique combination of very interesting piezoelectric, electrical, optical and thermal properties compared to other compound semiconductors.

These properties are already successfully applied in the fabrication of piezoelectric transducer, optical wave-guides, selective gas sensors, acoustic-optic devices and conductive transparent electrodes.

Now intensive studies are conducted around the world on:

  • LED and laser diodes in the UV region,
  • UV detectors,
  • > 5GHz devices,
  • high temperature, high electronic field and high power devices,
  • high quality large substrates for GaN,

Many works on ZnO are made on thin films grown by MBE using beams of Zinc and Atomic Oxygen.

For these applications ADDON has designed dedicated sources for each material:

  • A High Temperature Stability effusion cell for Zinc: Model VLT
  • A High Efficiency RF Plasma source for Atomic Oxygen production: Model RFO

Rheed spectrum taken during growth of ZnO layers*

Experimental Conditions :
  • Substrate Sapphire (0001)
  • Substrate temperature 500°C (5’’ Oxygen resistant oven)
  • Growth rate = 0,4 to 0,6 µm/h
  • Zn flux (effusion cell) BEP = 3 10-6 Torr
  • Atomic O flux : Addon RF Plasma Source
  • Growth chamber pressure (5 10 –8 - 5 10 –6 Torr)

* Courtesy of : CRHEA-CNRS Valbonne

A RF Plasma source for Atomic oxygen Flux production, the source itself is on a DN40CF flange (2 3/4”) connected to a DN63CF flange (4”) witch supports a pneumatic shutter for quick flux stop, this permits to perform the multilayers growths.

+/- 0,02 °C OR BETTER CELL STABILITY AT 50 ° TO 400 °C
(Very Low Temperature Cell Type)

This cell is the best adapted source for polymers, organic materials and high vapor pressure metals like Zn, Mg, Pb, Se, Sb etc…

Conventional effusion cells are not really adapted to work properly at such low temperatures (40 to 500 °C) and give both poor temperature stability and poor temperature change dynamics.
This is due to their excessive thermal mass and inadequate thermal exchange with the source environment. Conventional T/C’s (even K type) are also not well adapted for use at such low temperatures.
The ADDON design is a completely new, and patented concept of effusion cell, which has improved temperature stability/reproducibility and good thermal agility at low temperature. A Platinum Resistance Temperature sensor (PRTD) is used for the temperature measurement and control. Each source is equipped with its own cold source, which gives a very efficient thermal response.

If you need long term stability and reproducibility see more of this VLT NEW PRODUCT

The ADDON new shutter blades and shutter mechanisms for VARIAN GEN II

ADDON has developed a replacement actuator and blade unit for Varian 360 and Modular Gen II MBE systems which turns previously painful shutter exchange / adjustment into simple jobs, which can be conducted from outside the MBE chamber.
The unit is 100% compatible with the original system pneumatic actuator and offers many advantages, as summarized below.

  • easy to install, exchange, clean and adjust
  • easily adjusted from outside growth chamber
  • shutter position can be adjusted under vacuum
  • offers significant improvements in the degrees and range of shutter movement
  • robust shutter arm resistant to damage from sticking
  • indexed shutter arm
This product turns painful shutter exchange into an easy job.
The unit is 100% compatible with the system pneumatic actuator.
Tantalum arm and shutter blade
User replaceable
Plug-in and Tight fitting
Indexed blade arm
Up to +/- 20°
Blade positioning
+/- 4 mm
Blade Azimuthal orientation
Blade Tilt
+/- 4 mm
*Standard: Tantalum
Option: PBN, Mo, Water cooled
Model Number
Mechanism (set of 3) SMCH
Shutter blade* with rigid arm CSVA3
Mechanisms with Ta and PBN blades
Comparison table between original mechanism and ADDON’s
Original ADDON
Adjustment from atmosphere side No ALL
Adjustment when system under UHV No YES
Azimuthal Orientation None +/- 20°
Blade positioning None +/- 4 mm
Blade tilt None +/- 4 mm at blade
Indexed shutter arm No YES
Shutter arm Flexible tube Rigid bar

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