Uniform magnetically enhanced reactive ion etching using nested electromagnetic coils

A magnetic field-enhanced plasma reactor, comprising:

• a reaction chamber adapted to apply a plasma to a substrate;
• and
• a first and second set of primary electromagnets having inner and outer perimeters disposed about said reaction chamber, said first set of primary electromagnets being provided with a first adjustable current and said second set of primary electromagnets being provided with a second adjustable current;
• and
• a secondary electromagnet nested within the inner perimeter of one of said primary electromagnets;
• wherein the reactor is adapted to maintain the ratio R=I2/I1 during etching within the range −1<R<1, wherein I1 is the current provided by the first current source, wherein I2 is the current provided by the second current source, and wherein I1>I2;
• and
• wherein at least one of the primary electromagnets has at least one secondary electromagnet disposed within a region defined by a right rectangular prism having the largest perimeter that fits within the outer perimeter of the at least one primary electromagnet.

A magnetic field-enhanced plasma reactor, comprising:

• a reaction chamber adapted to apply a plasma to a substrate;
• and
• a first and second set of primary electromagnets having inner and outer perimeters disposed about said reaction chamber, said first set of primary electromagnets being provided with a first adjustable current and said second set of primary electromagnets being provided with a second adjustable current;
• and
• a secondary electromagnet nested within the inner perimeter of one of said primary electromagnets;
• wherein the reactor is adapted to maintain the ratio R=I2/I1, during etching within the range −1<R<1, wherein I1 is the current provided by the first current source, wherein I2 is the current provided by the second current source, and wherein I1>I2, and
• wherein at least one secondary electromagnet is disposed within a region defined by a right rectangular prism having the largest perimeter that fits within the inner perimeter of the at least one primary electromagnet.

A magnetic field-enhanced plasma reactor, comprising:

• a reaction chamber adapted to apply a plasma to a substrate;
• and
• a first and second set of primary electromagnets having inner and outer perimeters disposed about said reaction chamber, said first set of primary electromagnets being provided with a first adjustable current and said second set of primary electromagnets being provided with a second adjustable current;
• and
• a secondary electromagnet nested within the inner perimeter of one of said primary electromagnets;
• wherein the reactor is adapted to maintain the ratio R=I2/I1 during etching within the range −1<R<1, wherein I1 is the current provided by the first current source, wherein I2 is the current provided by the second current source, and wherein I1>I2, and
• wherein, for any given primary electromagnet, at least one secondary electromagnet is disposed within a region defined by a right rectangular prism having the largest perimeter that fits within the inner perimeter of said primary electromagnet.

A magnetic field-enhanced plasma reactor, comprising:

• a reaction chamber comprising a cathode and an anode that are adapted to apply a plasma to a substrate;
• a first and second primary electromagnet disposed about said reaction chamber and having a plane of orientation that is orthogonal to the surface of said cathode, said first and second primary electromagnets having an outer perimeter and an inner perimeter;
• and
• a first and second secondary electromagnet;
• wherein said first secondary electromagnet is disposed within a region defined by a right rectangular prism having the largest perimeter that fits within the outer perimeter of said first primary electromagnet, and wherein said second secondary electromagnet is disposed within a region defined by a right rectangular prism having the largest perimeter that fits within the outer perimeter of said second primary electromagnet.

A magnetic field-enhanced plasma reactor, comprising:

• a reaction chamber for applying a plasma to a substrate;
• a plurality of primary electromagnets surrounding said reaction chamber;
• and
• a plurality of secondary electromagnets, each of said secondary electromagnets being disposed in a nested relation with respect to one of said primary electromagnets.

A magnetic field-enhanced plasma reactor, comprising:

• a reaction chamber for applying a plasma to a substrate;
• a plurality of primary electromagnets surrounding said reaction chamber;
• and
• a plurality of secondary electromagnets, each of said secondary electromagnets being disposed in a nested relation with respect to one of said primary electromagnets;
• wherein at least two of said secondary electromagnets are adjacent to each other and are disposed within separate adjacent primary electromagnets.

A magnetic field-enhanced plasma reactor, comprising:

• a reaction chamber adapted to apply a plasma to a substrate;
• and
• a first and second set of primary electromagnets having inner and outer perimeters disposed about said reaction chamber, said first set of primary electromagnets being provided with a first adjustable current and said second set of primary electromagnets being provided with a second adjustable current;
• and
• a secondary electromagnet nested within the inner perimeter of one of said primary electromagnets;
• wherein the reactor is adapted to maintain the ratio R=I2/I1 during etching within the range −1<R<1, wherein I1 is the current provided by the first current source, wherein I2 is the current provided by the second current source, and wherein I1>I2, and
• wherein the reaction chamber comprises a cathode and an anode, and wherein said primary electromagnets each has a plane of orientation that is orthogonal to the surface of said cathode.