New Maria - Mini Multi Pocket Organic Vaporizer

FEATURES:

The SPECS Scientific MARIA is a mini organic evaporator capable of evaporating small quantities of almost any organic material. The instrument design incorporates four separate evaporation zones or pockets from which the materials may be evaporated. Each of the pockets is fitted with a thermocpouple allowing materials to be evaporated with highest uniformity. All 4 pockets have a fixed target position and may be user configured to customer's specifications.

The material in each crucible is heated evenly from the surrounding individual filament.

The high-precision design allowing evaporation temperatures of 750 degC to be reached.

The power supply is configured to supply power to each one of the pockets allowing synchronous evaporation of up to four different materials or larger quantities of a single material.

Low power ~50W may be used for high vapour pressure materials or up to 300 watts may be used for lower vapour pressure materials depending on the application and the deposition rate required.

The evaporator mounted on an 2.75"O.D. flange (NW35CF) is fully UHV compatible.

Applications:

Evaporation is possible of materials such as organic and biological materials and materials with low vapour pressure. Various Crucibles (60mm³) from various materials (W, Mo, Ta, Al2O3, PBN, PGR) can also be installed

As the materials evaporates, cruibles may be exchanged without breaking vacuum (optionally).

The deposition rates may be controlled from sub-monolayer/minute up to ~2nm/min and up to 1nm / second for higher vapour pressure materials at 10cm working distance, using the included 300W power supply and controller.

Examples:

Evaporation from crucible is usually manually controlled in combination with a quartz crystal monitor to indicate the deposited thickness. This is the most common use of the instrument and is ideal for depositing a few mono-layers of material.

Closed loop control may also be obtained using the integrated thermocouple to measure the . The monitor signal is amplified and fed back to a PID controller to regulate the supply. This method provides an direct qualitative measurement of the flux actually leaving the evaporator.

New Design Features:

(1) Co-Deposition for multiple materials with absence of any cross-contamination.

(2) MARIA has a unique configuration of 4 independent and physically isolated pockets with a combination of adjustable and fixed evaporation positions offering unparalleled flexibility and choice for the user.

(3) The incorporation of thermocouple feedthroughs for each crucible, means that there are no flexing leads in vacuum which can lead to fatigue and shorting problems.

(4) Each evaporation zone is entirely separate from the others with no line of sight between the pockets and is surrounded by a water-cooled jacket for negligible cross talk between pockets.

(5) Each evaporation zone is completely enclosed in a water-cooled copper shroud. The water sees only stainless steel and welded joints for long term corrosion resistance, with the stainless steel cooling pipes permanently bonded to the copper for complete and reliable thermal contact.

(6) Each filament assembly is constructed as an easily replaced unit and yet still allows the user to replace just the filament using standard tungsten wire. Spare filament assemblies can be purchased or prepared in advance and can be quickly and easily replaced.

(7) The filament encircles the crucible providing much more even heat distribution than one-sided filaments. Higher temperatures are therefore possible without local damage to crucibles.

(8) A long filament also provides more surface area for electron emission than shorter varieties allowing operation at lower temperatures with a consequent improvement in filament lifetime.

(9) Fine control of the electron emission current for improved operation at very low rates is provided as standard.

Specifications:
Mechanical
	Mounting flange:		2.75" (NW35CF)
	In vacuum length:		210mm (8.25") or customized to specification
	In vacuum diameter:		34mm (1.34") max
	Bakeout temperature:		200oC
	Thermocouple:		Permits measurement of the temperature near the crucible. Includes the thermocouple (Type K) and feedthrough
	Crucible volume:		60mm3
	Crucible materials:		W, Ta, Mo, Pyrolytic Graphite
	Crucible Liner materials:		PBN, Al2O3
Beam
	Deposition Rate:		Measured at 100mm: Higher vapour pressure materials: up to 1nm/second. Deposition rates controllable down to <0.01A/s = 0.2 monolayer/min.
	Beam Divergence:		~15o half angle ( ~10o with flux monitor fitted)
Power Supply
	Size:		19" rack mount. 3U height. 115V, 60Hz (230VAC, 50Hz optional)
	Heating Power:		0-300W, I=10 A, U=30V
	PID controller:		For PID control of the power supply, Eurotherm
Schematic Drawing and Electrical Diagrams for Beam Flux Monitor and Shutter
Options:
	1	Shutter:	For shutting off the beam. Manually operated.
	2	Shutter motorisation:	Solenoid drive. Requires option (1) above.
	3	Crucible Exchange:	Crucible Exchange without Breaking Vacuum With Z-Translator, Gatevalve, Differential Pumping Facilities
	4	Crucibles:	Mini-crucibles with 60mm3 capacity in a variety of materials including, W, Ta, Mo, PG (pyrolytic graphite). Matching lids also available.
	5	Crucible liners:	For reactive materials e.g. aluminium, an inert crucible liner is recommended. These are available in PBN and Alumina.