Lam Research Corporation

International Business Machines Corporation

Thomas E Wicker

Robert A Maraschin

Jian J Chen

William S Kennedy

Robert G Veltrop

Joel M Cook

Albert J Lamm

Michael S Barnes

John C Forster

John H Keller

Alan M Schoepp

Dennis K Coultas

Neil M Benjamin

Vahid Vahedi

An inductive plasma processor includes a multiple winding radio frequency coil having plural electrically parallel, spatially concentric windings (1) having different amounts of RF power supplied to them, and (2) arranged to produce electromagnetic fields having different couplings to different regions of plasma in the chamber to control plasma flux distribution incident on a processed workpiece. The coil is powered by a single radio frequency generator via a single matching network. Input and output ends of each winding are respectively connected to input and output tuning capacitors. In a first embodiment, the location of maximum inductive coupling of the radio frequency to the plasma and the current magnitude in each winding are respectively mainly determined by values of the output and input capacitors. By adjusting all the input and output capacitors simultaneously, the current to a winding can be varied while the current to the other winding can be maintained constant as if these windings were completely de-coupled and independent. Therefore, the capacitors can control the plasma density in different radial and azimuthal regions. In another embodiment, a relatively low frequency drives the coil whereby each winding has a relatively short electrical length, causing substantially small standing wave current and voltage variations. The output capacitor for each winding adjusts current magnitude, to eliminate the need for the input capacitors and reduce operational complexity.

Inductive plasma processor having coil with plural windings and method of controlling plasma density

A plasma processing chamber including a slip cast part having a surface thereof exposed to the interior space of the chamber. The slip cast part includes free silicon contained therein and a protective layer on the surface which protects the silicon from being attacked by plasma in the interior space of the chamber. The slip cast part can be made of slip cast silicon carbide coated with CVD silicon carbide. The slip cast part can comprise one or more parts of the chamber such as a wafer passage insert, a monolithic or tiled liner, a plasma screen, a showerhead, dielectric member, or the like. The slip cast part reduces particle contamination and reduces process drift in plasma processes such as plasma etching of dielectric materials such as silicon oxide.

Semiconductor processing equipment having improved process drift control

An inductive plasma processor includes an RF plasma excitation coil having plural windings, each having a first end connected in parallel to be driven by a single RF source via a single matching network. Second ends of the windings are connected to ground by termination capacitors, in turn connected by a lead to ground. A current sensor including a winding around a toroidal core is coupled to the lead between each termination capacitor and ground. The current sensor is surrounded by a grounded shield. There is minimum electromagnetic interference from an ambient RF environment to the current sensor, to provide an accurate current sensor.

Inductive plasma processor including current sensor for plasma excitation coil

A plasma processing chamber having a chamber liner and a liner support, the liner support including a flexible wall configured to surround an external surface of the chamber liner, the flexible wall being spaced apart from the wall of the chamber liner. The apparatus can include a heater thermally connected to the liner support so as to thermally conduct heat from the liner support to the chamber liner. The liner support can be made from flexible aluminum material and the chamber liner comprises a ceramic material. The flexible wall can include slots which divide the liner support into a plurality of fingers which enable the flexible wall to absorb thermal stresses.

Low contamination high density plasma etch chambers and methods for making the same

A radio frequency excitation coil of an inductive plasma processor includes a planar turn connected in series with a segment of the coil stacked above a portion of the planar turn. The stacked segment is placed around a region having weak radio frequency coupling to plasma due to azimuthal asymmetries in the chamber and/or the excitation coil. In a single winding embodiment, the stacked segment is close to an interconnection gap between two adjacent planar turns and extends in both directions from the gap to compensate low radio frequency coupling to plasma in the gap region. In an embodiment including two electrically parallel spatially concentric windings, the stacked segment extends beyond one side of an interconnection gap of two adjacent turns, and is aligned with the planar turn such that one end of the stacked segment is directly connected to an end of the planar turn via a straight, short stub. Terminals of the coil are connected to RF excitation circuitry terminals in a housing above the coil by leads extending smoothly and gradually without sharp bends between the coil terminals and the excitation circuitry terminals. Ends of the planar turn and the stacked segment are connected by a lead extending smoothly and gradually without sharp bends between its ends.

Stacked RF excitation coil for inductive plasma processor

A plasma processing chamber includes a substrate holder and a member of silicon carbide such as a liner, focus ring, perforated baffle or a gas distribution plate, the member having an exposed surface adjacent the substrate holder and the exposed surface being effective to minimize contamination during processing of substrates. The chamber can include an antenna which inductively couples RF energy through the gas distribution plate to energize process gas into a plasma state.

Contamination controlling method and apparatus for a plasma processing chamber

A radio frequency plasma multiple-coil antenna allows for controllable, uniform inductive coupling within a plasma reactor. According to exemplary embodiments, multiple coils are positioned on a dielectric window of a plasma chamber, and are powered by a single radio frequency generator and tuned by a single matching network. Each coil is either planar or a combination of a planar coil and a vertically stacked helical coil. The input end of each coil is connected to an input tuning capacitor and the output end is terminated to the ground through an output tuning capacitor. The location of the maximum inductive coupling of the radio frequency to the plasma is mainly determined by the output capacitor, while the input capacitor is mainly used to adjust current magnitude into each coil. By adjusting the current magnitude and the location of the maximum inductive coupling within each coil, the plasma density in different radial and azimuthal regions can be varied and controlled, and therefore, radially and azimuthally uniform plasma can be achieved.

Multiple coil antenna for inductively-coupled plasma generation systems

In a plasma processing system for processing substrates such as semiconductor wafers, deposition of polymer in an area between a focus ring and an electrostatic chuck in a plasma processing chamber is achieved by providing a clearance gas in a gap between the chuck and the focus ring. A series of channels delivers the clearance gas to the annular gap between the outer surface of the substrate support and the inner surface of the focus ring surrounding the substrate support. The clearance gas supplied to the annular gap is preferably a gas such as helium which will not affect the wafer processing operation. In the case of plasma etching, the clearance gas is supplied at a flow rate which is sufficient to block the migration of process gas and volative byproducts thereof into the annular gap without adversely affecting edge etch performance.

Apparatus for reducing polymer deposition on substrate support

A plasma processing chamber includes a substrate holder and a member of silicon nitride such as a liner, focus ring or a gas distribution plate, the member having an exposed surface adjacent the substrate holder and the exposed surface being effective to minimize particle contamination during processing of substrates. The chamber can include an antenna which inductively couples RF energy through the gas distribution plate to energize process gas into a plasma state.

Particle controlling method for a plasma processing chamber

A plasma processing chamber including a ceramic liner heated by radiant heating. The liner can be a series of tiles or a continuous cylindrical liner. The liner and other parts such as a gas distribution plate and a plasma screen can be made of SiC which advantageously confines the plasma and provides temperature control of the inner surfaces of the chamber. To remove excess heat from the liner, the ceramic liner can be supported on a resilient aluminum support frame which conducts heat from the liner to a temperature controlled member such as a top plate of the chamber. The support frame can include a continuous upper portion and a segmented lower portion which allows thermal stresses to be accommodated during processing of semiconductor substrates in the plasma chamber.

Semiconductor processing equipment having radiant heated ceramic liner

A method and apparatus for controlling deposit build-up on an interior surface of a dielectric member of a plasma processing chamber. The deposit build-up is controlled by selective ion bombardment of the inner surface by shifting location of a peak voltage amplitude of a voltage standing wave on an antenna such as a flat spiral coil of the plasma processing chamber. A region of high ion bombardment on the interior surface of the dielectric member is displaced by controlling the value of a termination capacitance over a range of values causing regions of low and high ion bombardment to move over the dielectric member in order to effect cleaning thereof.

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Reno, NV, United States of America

Thomas E Wicker