Applied Materials, Inc.

Kuang-Han Ke

Hongching Shan

Bryan Y Pu

Michael D Welch

Zongyu Li

Roger Alan Lindley

James Chang Wang

Henry Fong

Ling Chen

Alfred W Mak

Semyon Sherstinsky

Claes H Bjorkman

Richard W Plavidal

Richard Raymond Mett

Ji Ding

Leonel Arturo Zuniga

Samuel C Wilson

Xue Yu Qian

Sue Zhang

A ring or collar surrounding a semiconductor workpiece in a plasma chamber. According to one aspect, the ring has an elevated collar portion having an inner surface oriented at an obtuse angle to the plane of the workpiece, this angle preferably being 135&deg;. This angular orientation causes ions bombarding the inner surface of the elevated collar to scatter in a direction more parallel to the plane of the workpiece, thereby reducing erosion of any dielectric shield at the perimeter of the workpiece, and ameliorating spatial non-uniformity in the plasma process due to any excess ion density near such perimeter. In a second aspect, the workpiece is surrounded by a dielectric shield, and the shield is covered by a non-dielectric ring which protects the dielectric shield from reaction with, or erosion by, the process gases. In a third aspect, the dielectric shield is thin enough to couple substantial power from the cathode to the plasma, thereby improving spatial uniformity of the plasma process near the perimeter of the workpiece. In a fourth aspect, azimuthal non-uniformities in process performance can be ameliorated by corresponding azimuthal variations in the dimensions of the elevated collar and/or the dielectric shield surrounding the workpiece.

Shield or ring surrounding semiconductor workpiece in plasma chamber

A plasma chamber having a magnet which produces a magnetic field such that, within a region parallel to and adjacent to the workpiece, the direction of the magnetic field is approximately the vector cross product of (i) the gradient of the magnitude of the magnetic field, and (ii) a vector extending perpendicularly from the workpiece surface toward the plasma. Alternatively, the plasma chamber includes a north magnetic pole and a south magnetic pole located at distinct azimuths around the periphery of the workpiece. The azimuth of the south magnetic pole relative to the north magnetic pole is clockwise around the central axis, and each magnetic pole faces a direction which is more toward than away from a central axis of the workpiece area. An additional aspect of the invention is a plasma chamber having a rotating magnetic field produced by electromagnets spaced around the periphery of the workpiece which receive successive fixed amounts of electrical current during successive time intervals. During each transition between the time intervals, the current supplied to each electromagnet is changed relatively slowly or relatively quickly according to whether the current change includes a change in polarity.

Magnetically-enhanced plasma chamber with non-uniform magnetic field

A diagnostic pedestal assembly for measuring ion current and DC bias voltage within a high-power plasma reaction chamber of a semiconductor wafer processing system. The diagnostic pedestal assembly contains an aperture located in a surface of the pedestal and a probe element that is supported within the aperture.

Diagnostic pedestal assembly for a semiconductor wafer processing system

Apparatus for retaining a wafer having improved wafer and chuck edge protection, contains an protection ring that circumscribes a pedestal and is biased to be in constant contact with the backside of the wafer. A biasing element uniformly biases the protection ring into contact with the circumferential edge of the wafer. The protection ring has an annular plan form that circumscribes an electrostatic chuck for retaining the wafer in a stationery position. Vertical travel of the ring is restricted by a hard stop that is formed by a portion of a focus ring which overhangs the protection ring. After a wafer is placed upon the chuck and the chucking force enabled, the chucking force easily overcomes the bias force upon the protection ring and the wafer rests upon the chuck support surface. The protection ring contacts the backside of the wafer to ensure that pedestal and electrostatic chuck are not exposed to the plasma and, when a silicon protection ring is used, the effective area of the wafer is extended beyond the physical dimensions of the wafer to facilitate a more uniform plasma distribution over the wafer.

Apparatus for improving wafer and chuck edge protection

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Mountain View, CA, United States of America

Kuang-Han Ke