Magnetic field-enhanced plasma etch reactor
First Claim
1. A vacuum processing reactor, comprising a housing defining a vacuum chamber therein adapted for etching a wafer positioned within the chamber at a high rate and with etching uniformity substantially independent of pressure, comprising:
- a pedestal having a convex-shaped surface for supporting the wafer in a bowed configuration parallel to the pedestal surface;
a gas manifold for supplying reactant gases to the chamber;
means for applying RF energy between the wafer support pedestal and the gas manifold for generating a wafer etching plasma;
electric current-controlled magnetic field generating means for forming a D.C. magnetic field generally parallel to the wafer surface;
means for selectively applying current to the field generating means for independently controlling the intensity and orientation of the magnetic field; and
means for applying gas under pressure between the surface of the pedestal and the wafer to provide uniform thermal conduction between the wafer and the pedestal.
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Accused Products
Abstract
A magnetic field enhanced single wafer plasma etch reactor is disclosed. The features of the reactor include an electrically-controlled stepped magnetic field for providing high rate uniform etching at high pressures; temperature controlled reactor surfaces including heated anode surfaces (walls and gas manifold) and a cooled wafer supporting cathode; and a unitary wafer exchange mechanism comprising wafer lift pins which extend through the pedestal and a wafer clamp ring. The lift pins and clamp ring are moved vertically by a one-axis lift mechanism to accept the wafer from a cooperating external robot blade, clamp the wafer to the pedestal and return the wafer to the blade. The electrode cooling combines water cooling for the body of the electrode and a thermal conductivity-enhancing gas parallel-bowed interface between the wafer and electrode for keeping the wafer surface cooled despite the high power densities applied to the electrode. A gas feed-through device applies the cooling gas to the RF powered electrode without breakdown of the gas. Protective coatings/layers of materials such as quartz are provided for surfaces such as the clamp ring and gas manifold. The combination of these features provides a wide pressure regime, high etch rate, high throughput single wafer etcher which provides uniformity, directionality and selectivity at high gas pressures, operates cleanly and incorporates in-situ self-cleaning capability.
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Citations
16 Claims
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1. A vacuum processing reactor, comprising a housing defining a vacuum chamber therein adapted for etching a wafer positioned within the chamber at a high rate and with etching uniformity substantially independent of pressure, comprising:
- a pedestal having a convex-shaped surface for supporting the wafer in a bowed configuration parallel to the pedestal surface;
a gas manifold for supplying reactant gases to the chamber;
means for applying RF energy between the wafer support pedestal and the gas manifold for generating a wafer etching plasma;
electric current-controlled magnetic field generating means for forming a D.C. magnetic field generally parallel to the wafer surface;
means for selectively applying current to the field generating means for independently controlling the intensity and orientation of the magnetic field; and
means for applying gas under pressure between the surface of the pedestal and the wafer to provide uniform thermal conduction between the wafer and the pedestal. - View Dependent Claims (2, 5, 7, 8, 9, 10)
- a pedestal having a convex-shaped surface for supporting the wafer in a bowed configuration parallel to the pedestal surface;
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3. A vacuum processing reactor comprising a housing defining a vacuum chamber therein adapted for processing of a wafer positioned within the chamber, the housing having an opening therein to allow insertion of a horizontally oriented wafer into the chamber, to a first selected position, and removal of the wafer from the chamber;
- said adaptation further comprising;
a pedestal assembly having an upper face for supporting the wafer in a generally horizontal orientation, said pedestal face being generally aligned with the first selected position; wafer exchange means comprising a group of generally vertically-oriented pins extending through holes in the pedestal; and means for sequentially moving the wafer exchange means upwardly and downwardly to selected positions for removing the wafer from the first selected position, clamping the wafer to the pedestal and returning the wafer to the selected position. - View Dependent Claims (6)
- said adaptation further comprising;
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4. A vacuum processing reactor comprising a housing defining a vacuum chamber therein adapted for processing of a wafer positioned within the chamber, the housing having an opening therein to allow insertion of a horizontally oriented wafer into the chamber, to a first selected position, and removal of the wafer from the chamber;
- said adaptation further comprising;
a pedestal assembly having a horizontal upper face for supporting the wafer, said pedestal face being generally aligned with the first selected position; wafer exchange means comprising a clamping ring means having the axis thereof oriented generally parallel to the pedestal and a group of generally vertically oriented pins arranged in a circular array of diameter less than the clamp ring diameter, said upper ends of the pins being spaced vertically below said clamping ring; and means for sequentially moving the wafer exchange means upwardly and downwardly to selected positions for removing the wafer from the first selected position, clamping the wafer to the pedestal and returning the wafer to the selected position.
- said adaptation further comprising;
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11. A vacuum processing reactor comprising a housing defining a vacuum chamber therein adapted for the processing of a wafer positioned within the chamber, the housing having an opening therein for receiving a wafer-support blade and further comprising:
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means for lifting the wafer from the blade, positioning of the wafer on the pedestal, and returning the wafer to the blade; a gas manifold for supplying reactive gas to the chamber; means for applying RF energy between the pedestal and the manifold to form an etching plasma from the reactive gas for etching the wafer; and magnetic field generating means comprising at least first and second pairs of electromagnets disposed about the housing for forming a D.C. magnetic field parallel to the wafer surface; and
means for applying current to the electromagnets to step the D.C. field over the surface of the wafer to provide a uniform etch plasma. - View Dependent Claims (12, 13, 14, 15, 16)
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Specification