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 | Only Source With Integral Gas Injection - Additional Feedthroughs & Manifolds Unnecessary |
| Stable Operation at Very Low Powers & Rates |
| Power Levels 2x Compared to Competing Designs. |
| Modular Design |
| Tilt Mechanism, Variable Positioning, Shutters & Feedthrough Adaptors Among Standard Options. |
| Customized Designs Available |
| "Unbalanced" Magnet Arrays & magnet Modules for Magnetic Materials Are Available |
| Bonded, Clamped & Directly Cooled Targets |
| Suitable for DC, Pulsed DC, RF & AC Power Modes |
What Makes Polaris™ Sources Different?
Polaris™ sources provide industrial robustness and performance in a small package. They can operate stably at low 10-4 Torr background pressures at very low power levels. Conversely, because cooling water flow rates through the sources are nearly 2.5x that of competing sources, extremely high power levels can be achieved using directly water cooled targets during long process runs and pre-commercial development efforts.
Good Vacuum Practice
It's unlikely that you will consider fastener sizes when selecting a small sputtering source. We do. Small diameter fasteners gall more easily in vacuum and seize. We use larger, course thread screws. Threaded connections in vacuum - especially those exposed to heat and redeposited material, whether on target clamps or "adjustable" ground/anode sheilds are a bad idea. Not being able to exchange a target or having to use a hammer to service the source when conducting a critical experiment suddenly becomes a big issue not previously contemplated.
Simple, Compact & Reliable
Most sources are installed in relatively small chambers, so compactness is important. Adding gas manifolds, "chimneys" and other optional features increases size, expense and complexity. O-ring sealed, push-to-connect water fittings eliminate water leakage, especially when the cooling lines have a tight radius. The stainless steel water line tubes are easily replaced if damaged. Ultem insulators ensure that all types of power supplies can be used, and that the insulators won't crack, arc or cold flow. Stainless steel anode/ground shields and KF-40 bulkhead clamps eliminate arcing caused by native oxide growth, especially in the presence of other plasma and ion sources that aren't sufficiently neutralized. All parts exposed to vacuum are UHV precision cleaned or electropolished.
Better Process Control
Because gas is injected through Polaris™ cathode bodies, process benefits are obtained (stable, low pressure operation, reduced insulating film growth and backscattered material on the target surface. - reduced arcing, denser films, better control of stoichiometry, etc.) and the source stays small. Process geometry variability becomes limited the bigger the source in small chambers. Target material is deposited on manifolds, chimneys, sheilds and flakes off - causing arcing, shorting and other bad stuff. The less surface area the better. When gas distributors/manifolds sold by our competitorsare connected through the chamber wall at ground potential, the probability that the plasma will be disturbed increases (non-uniform films), rates drop and base pressures increase (lower ionization efficiency because electrons will more likely follow the ground path instead of remaining present in the plasma discharge.
A Lasting Investment
Polaris™ sources emphasize a robust design, reliability, ease of maintenance and a low cost of ownership. We think you don't get good value for money if the purchase price is low, but the cost of maintenance is high and reliability low. The use of welded and brazed assemblies lowers the manufacturing cost, but doesn't consider how difficult it makes the source to clean and service. Aluminum erodes easily when vapor honed, grit blasted or, in most cases, chemically cleaned. A brazed insulator assembly or a feedthrough with a bellows welded to it experiencing a vacuum leak is an expensive repair. Every component in Polaris™ sources subjected to normal operation can be serviced or replaced by the user on site using, in most cases, commercially available parts and hardware.
Target Mounting
Clamped Target Arrangement Bonded Target Directly Water-Cooled Target
Targets
may be bonded, clamped or directly water-cooled, depending upon the target
material, user preference and power level. Brittle, soft and low thermal
conductivity materials should be bonded to the backing plate. This
minimizes hot spots, insulating film growth and permits much higher power levels
and rates of deposition compared to clamped targets. Targets can be
clamped to a semi-permanent backing plate that remains attached to the cathode
body. This method is appropriate only when low power levels are used for
short duration. Directly water-cooled targets are recommended for high
power/high rate sputtering of mechanically strong materials like refractory
materials.
Magnetics
The magnet module resides in the cooling water cavity, ensuring maximum protection from overheating. The discrete magnets within the module are completely encapsulated and are protected from exposure to water. Polaris™ sources are supplied with a balanced magnet array as standard. Custom arrays for "unbalanced" magnetron sputtering and for sputtering magnetic materials can also be supplied. These arrays require a discussion with the customer about materials, process and expectations.
Modular Design Allows a Very Wide Range of Installation Possibilities
The basic sputtering source has a KF-40 bulkhead flange. Power, water and gas connections are made at atmosphere within it. A variety of standard feedthrough and installation kits mating with this flange are offered. To obtain the Installation Control Drawing for the specfic configuration that meets your needs, CLICK HERE.
Please contact the factory if you don't find what you need on this web site.
Low cost sputtering packages are also available for those on tight budgets.
Copyright © 1993-2008 Materials Science, Inc.
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