Plasma desmearing apparatus and method

A method for desmearing objects inserted within a chamber, the chamber including a power electrode spaced apart a sufficient distance from a ground electrode connected to ground to permit the insertion of one or more of the objects therebetween, comprising the steps of:

• evacuating the chamber to a very low pressure;
• supplying an amount of electrical energy at a radio frequency to the power electrode to create an electrical field between the power electrode and the ground electrode;
• decreasing the intensity of the electrical field thus created from the central area of the power electrode to the outer peripheral area of the power electrode;
• and
• directing a flow of gas between the power electrode and the ground electrode.

A method for desmearing objects inserted within a chamber, the chamber including pairs of electrode spaced apart a sufficient distance to permit the insertion of one or more of the objects between adjacent electrode pairs, each electrode pair including a power electrode for receiving electrical energy and a ground electrode connected to ground, comprising the steps of:

• evacuating the chamber to a very low pressure;
• supplying an amount of electrical energy at a radio frequency to the power electrode of each electrode pair to create a primary electrical field between the power electrode and the ground electrode of a first electrode pair and a secondary electrical field between the power electrode of the first electrode pair and the ground electrode of a second and preceeding electrode pair;
• decreasing the intensity of the primary electrical field created by the first electrode pair from the central area to the outer peripheral areas of the power electrode of the first electrode pair;
• and
• directing a flow of gas through the electrode pairs.

An apparatus for desmearing objects with a gas excited within an electrical field, comprising in combination:

• a chamber;
• lid means connected to said chamber for providing access to the interior of said chamber;
• means for connecting the ends of said chamber to a reduced pressure source;
• means for introducing a gas into said chamber at a first end of said chamber when said chamber is substantially evacuated by said reduced pressure source;
• a first and second porous electrode pairs positioned transfersely within said chamber in a spaced apart relationship to permit the insertion of one or more of the objects to be desmeared therebetween, said first electrode pair being positioned closer to said first end of said chamber than said second electrode pair;
• each of said electrode pairs including a ground electrode and a power electrode;
• means for connecting each of said ground electrodes to ground;
• a first and second generator means providing a first and a second supply of electrical energy at a radio frequency, said second supply being greater than said first supply;
• and
• means for connecting said first generator means to said power electrode of said first electrode pair and for connecting said second generator means to said power electrode to said second electrode pair to create primary and secondary electrical fields of two different intensities within said chamber, whereby the gas flows first through said first electrode pair and then through said second electrode pair such that the increased intensity of the electrical fields created by said second electrode pair compensates for the saturation of the gas flowing therethrough.