Application of variable bias voltage on a cylindrical grid enclosing a target

Claim 2

A plasma ion surface modification apparatus, the apparatus comprising: a reaction vessel having a reaction chamber, said chamber having a base and being coupled with a plasma source; an electrode centrally positioned on said base within said chamber; and a perforated grid positioned within said chamber, said grid enclosing a target zone, wherein a separate and independently variable biasing voltage is concurrently applied to each of said grid and said electrode, and wherein said grid biasing voltage is about 50% to 99% less than said electrode biasing voltage.

Claim 3

The apparatus of claim 1 , wherein said electrode biasing voltage is a square wave, and wherein said grid biasing voltage is one of a square wave or a direct current.

Claim 4

The apparatus of claim 2 , wherein a square waveform applied to said perforated grid synchronizes with or overlaps a square waveform applied to said electrode.

Claim 5

The apparatus of claim 1 , further comprising: a sputtering voltage applied to said grid to sputter a desired material onto a target device, said sputtering voltage superimposed on said biasing voltage applied to said grid.

Claim 6

The apparatus of claim 4 , wherein said sputtering voltage is a direct current (DC) of up to approximately 1000V.

Claim 7

A plasma ion surface modification apparatus, the apparatus comprising: a reaction vessel having a reaction chamber, said chamber having a base and being coupled with a plasma source; an electrode centrally positioned on said base within said chamber; a perforated grid positioned within said chamber, said grid enclosing a target zone; and means to apply a biasing voltage to each of said grid and said electrode comprising a voltage source operatively associated with said electrode and with said perforated grid, said means coupled with each of said grid and said electrode, wherein said voltage source includes a voltage divider to apply a first voltage to said electrode and a second voltage to said perforated grid, and wherein said second voltage is about 50% to about 99% less than said first voltage.

Claim 8

A plasma ion surface modification apparatus, the apparatus comprising: a reaction vessel having a reaction chamber, said chamber having a base and being coupled with a plasma source; an electrode centrally positioned on said base within said chamber; a perforated grid positioned within said chamber, said grid enclosing a target zone; and means to apply a biasing voltage to each of said grid and said electrode comprising a voltage source operatively associated with said electrode and with said perforated grid, said means coupled with each of said grid and said electrode, wherein said voltage source includes a voltage divider to apply a first voltage to said electrode and a second voltage to said perforated grid, and wherein said second voltage is about 50% to about 99% less than said first voltage.

Claim 9

A plasma ion surface modification apparatus, the apparatus comprising: a reaction vessel having a reaction chamber, said chamber having a base and being coupled with a plasma source; an electrode centrally positioned on said base within said chamber; a perforated grid positioned within said chamber, said grid enclosing a target zone; and means to apply a biasing voltage to each of said grid and said electrode comprising a voltage source operatively associated with said electrode and with said perforated grid, said means coupled with each of said grid and said electrode, wherein said means to apply a biasing voltage to each of said perforated grid and said electrode comprises: a first voltage source operatively associated with said electrode to provide an electrode voltage; and a second voltage source operatively associated with said perforated grid to provide a grid voltage, and wherein said grid voltage is about 50% to about 99% less than said electrode voltage.

Claim 10

A plasma ion surface modification apparatus, the apparatus comprising: a reaction vessel having a reaction chamber, said chamber having a base and being coupled with a plasma source; an electrode centrally positioned on said base within said chamber; a perforated grid positioned within said chamber, said grid enclosing a target zone; and means to apply a biasing voltage to each of said grid and said electrode comprising a voltage source operatively associated with said electrode and with said perforated grid, said means coupled with each of said grid and said electrode, wherein said means to apply a biasing voltage to each of said perforated grid and said electrode comprises: a first voltage source operatively associated with said electrode to provide an electrode voltage; and a second voltage source operatively associated with said perforated grid to provide a grid voltage, and wherein said grid voltage is about 50% to about 99% less than said electrode voltage.

Claim 13

The method of claim 8 , wherein said perforated grid is cylindrical.

Claim 14

The method of claim 8 , wherein said target is a stent or a catheter.

Claim 15

The method of claim 8 , wherein a surface of said target is modified to comprise a biocompatible material.

Claim 16

The method of claim 8 wherein a surface of said target is modified to comprise one of a radio-absorbent material or a radioactive material.

Claim 17

The method of claim 12 , wherein said radioactive material is selected from the group consisting of: tin (P-32), potassium (K-40), and phosphine (P-32).

Claim 18

The method of claim 8 , further comprising: positioning a cooling device within said chamber to cool a target positioned within said target zone.

Claim 19

The method of claim 14 , wherein said cooling device includes: an inner target stage, said inner target stage having at least one aperture therein through which a coolant can pass; an outer target stage surrounding said inner target stage; a reservoir to store the coolant; and a pump operatively coupled with said inner target stage and said reservoir to pump coolant from said reservoir through said inner target stage.

Claim 20

The method of claim 15 , wherein said coolant is one of a liquid or a gas.

Claim 21

The method of claim 8 , wherein said first biasing voltage is a pulsed voltage and said second biasing voltage is one of a pulsed voltage or a direct current.

Claim 22

The method of claim 17 , wherein said voltage source pulses said first biasing voltage synchronously with said second biasing voltage.

Claim 23

The method of claim 17 , wherein said voltage source overlaps said first pulsed biasing voltage and said second pulsed biasing voltage.