Applied Materials, Inc.

Richard Blume

James D Carducci

Bryan Y Pu

Michael D Welch

Paul E Luscher

Robert W Wu

Evans Yip Lee

Hongching Shan

Hong Ching Shan

Michael Dutcher

Hans Petrusk

A method of adjusting the cathode DC bias in a plasma chamber for fabricating semiconductor devices. A dielectric shield is positioned between the plasma and a selected portion of the electrically grounded components of the chamber, such as the electrically grounded chamber wall. The cathode DC bias is adjusted by controlling one or more of the following parameters: (1) the surface area of the chamber wall or other grounded components which is blocked by the dielectric shield; (2) the thickness of the dielectric; (3) the gap between the shield and the chamber wall; and (4) the dielectric constant of the dielectric material. In an apparatus aspect, the invention is a plasma chamber for fabricating semiconductor devices having an exhaust baffle with a number of sinuous passages. Each passage is sufficiently long and sinuous that no portion of the plasma within the chamber can extend beyond the outlet of the passage. By blocking the plasma from reaching the exhaust pump, the exhaust baffle reduces the deposition of unwanted particles on exhaust pump components. The exhaust baffle also reduces the cathode DC bias by reducing the effective surface area of the electrically grounded chamber wall which couples RF power to the plasma.

Adjusting DC bias voltage in plasma chamber

Adjusting DC bias voltage in plasma chambers

An improved, process compatible fastener is especially useful for securing a member, such as a wafer clamp ring, to an assembly for use in a process environment. The fastener is of a simple design, such that it is readily manufactured, and such that it is not a source of contamination. In particular, an integrated fastener includes both a metal fastener and a cone shaped metal lock washer within a single fastener assembly, such that a single fastener is used for accomplish the function of a screw and a washer. All surfaces of the fastener that are exposed within the process environment are encapsulated in a process compatible material. In this way, the fastener may be secured in the process environment in a single operation without leaving any gaps or partially exposed surfaces that may introduce contaminants into the process environment, such that the integrated fastener also provides the function of a process compatible cap.

Encapsulated fastener

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San Jose, CA, United States of America

Richard Blume