Tuned potential pedestal for mask etch processing apparatus

Abstract

The present invention generally provides an improved pedestal for supporting a substrate. The pedestal has greatest application during a plasma etching process, such as for a quartz photomask, or “reticle.” The pedestal defines a body, and a substrate support base along an upper surface of the body. The substrate support base has an outer edge, and an intermediate substrate support ridge for receiving and supporting the substrate. At least a portion of the substrate support base outside of the intermediate substrate support ridge is fabricated from a dielectric material. The purpose is to couple greater RF power through the reticle in order to enhance the plasma etching process.

Description

CROSS-REFERENCE TO RELATED APPLICATIONS [0001] The present application claims priority to previously filed provisional patent application Ser. No. 60 / 531,062, filed Dec. 19, 2003, entitled “Tuned Potential Pedestal for Mask Etch Processing Apparatus.” The provisional application is incorporated herein by referenced in its entirety.BACKGROUND OF THE INVENTION [0002] 1. Field of the Invention [0003] The present invention generally relates to the fabrication of integrated circuits. More specifically, the invention relates to an apparatus for manufacturing a photomask, or “reticle,” useful in manufacturing semiconductors. [0004] 2. Description of the Related Art [0005] Integrated circuits (IC) are manufactured by forming discrete semiconductor devices on a surface of a semiconductor substrate. An example of such a substrate is a silicon (Si) or silicon dioxide (SiO2) wafer. To interconnect the devices on the substrate, a multi-level network of interconnect structures is formed. Material...

AI Technical Summary

Benefits of technology

[0015] The pedestal defines a body, and a base along on an upper surface of the body. The body receives an RF power during substrate processing. The substrate support base has an outer edge, and an intermediate substrate support ridge for receiving and supporting the substrate. At least a portion of the substrate support base outside of the intermediate substrate support ridge is fabricated from a dielectric material, or material having a lower dielectric constant than the remaining support base. An example is quartz. Quartz has a lower dielectric constant than the materials typically used for fabricating the pedestal body or cover, e.g., alumina. The placement of quartz allows greater RF power to be coupled through the reticle, thereby enhancing the plasma etching process. It also provides greater control over the relative amount of RF power coupled through the reticle.

Problems solved by technology

However, the photoresist layer is only selectively exposed.

This limitation is compounded by a gap typically existing between the reticle and the supporting pedestal therebelow.

In addition, when the surface area of the pedestal is large compared to the reticle area, the RF power may preferentially couple to other regions of the pedestal, producing a loss of RF power.

Further, it has been observed that the use of a pedestal cover, e.g., cover ring and capture ring, fabricated from a dielectric material is inadequate to lessen the power coupled through the region of the pedestal that is not immediately below the reticle.

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