Thin Film Deposition Attempt #1

IMAG1342

With a spare roughing pump laying around the fusion lab, I attempted to sputter copper onto a glass microscope slide.  A makeshift bell-jar was constructed from a pickle jar and high voltage feed-through was constructed using an alumina sheath and threaded steel rod.  A circular piece of sheet metal was fastened to the end of the steel rod to act as the electrode.  The edges of the sheet metal were polished to prevent arcing and corona formation.  This provided for a stable glow discharge when the chamber was pumped down and high voltage applied.

A makeshift HV power supply was fashioned from an CCFL inverter feeding a Cockroft-Walton style multiplier circuit.  This circuit easily provided the necessary high voltage to ignite the plasma, but would heat up considerably as it struggled to supply enough current to sustain a robust glow discharge.

Makeshift HV Supply

To increase the rate of deposition, a magnetron was fashioned from a pair of ring magnets salvaged from a microwave oven and a couple of neodymium disk magnets.  In the presence of the magnetic field set up by the magnetron, the electrons move in a long helical path increasing their chance of ionizing a neutral atom.

Magnetron

The introduction of the magnetron under the target material confined the plasma to a dense ring and increased the current flow considerably indicating an increase in the ion pollution.

RESULTS:

The makeshift power supply experienced significant heating and the experiment was terminated after about a minute of operation.  Inspection of the copper target showed a visible plasma burn in the shape of ring. Little discoloration was observed on the microscope slide.

The plasma was successfully confined by the magnetron and an increase in ion population was observed by its introduction.

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