Etching apparatus for semicondutor fabrication

Abstract

Method of operating an apparatus which allows etching different substrate etch areas of a substrate having different pattern densities at essentially the same etch rate. The apparatus includes (a) a chamber; (b) an anode and a cathode in the chamber; and (c) a bias power system coupled to the cathode, wherein the cathode includes multiple cathode segments. The operation method is as follows. A substrate to be etched is placed between the anode and cathode, wherein the substrate includes N substrate etch areas, and the N substrate etch areas are directly above the N cathode segments. N bias powers are determined which when being applied to the N cathode segments during an etching of the substrate, will result in essentially a same etch rate for the N substrate etch areas. Then, the bias power system is used to apply the N bias powers the N cathode segments.

Description

[0001] This application is a divisional application claiming priority to Ser. No. 10 / 906,627, filed Feb. 28, 2005.BACKGROUND OF THE INVENTION [0002] 1. Technical Field [0003] The present invention relates to etching tools for semiconductor and photomask fabrication, and more specifically, to etching tools for dry etching. [0004] 2. Related Art [0005] A conventional fabrication process usually involves the step of dry etching a top surface of a substrate (e.g., a wafer or a photomask). Typically, first, a photoresist layer or any useful masking layer can be applied to the substrate. Then, the mask layer can be patterned using a photolithography process so that only areas of substrate that need to be etched are exposed from underneath the masking layer. The other areas of the substrate that need to be kept intact are covered by the patterned masking layer. Next, the substrate (with the patterned masking layer on top) can be placed on the cathode of an etching chamber. A radio frequenc...

AI Technical Summary

Benefits of technology

The present invention provides an apparatus and method for etching substrates using a plasma generated in a chamber. The apparatus includes a chamber, an anode, a cathode, and a bias power system. The cathode has multiple segments that are insulated from each other and the bias power system applies separate power to each segment. This allows for a consistent etch rate across the substrate, even if different areas have different pattern densities. The technical effect is a more uniform and efficient etching process.

Problems solved by technology

As a result, fewer etchants are available for further etching in the first substrate etch area than in the second substrate etch area.

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