Stepped upper electrode for plasma processing uniformity

Abstract

A plasma discharge electrode having a front surface with a central portion thereof including gas outlets discharging a process gas which forms a plasma and a peripheral portion substantially surrounding the gas outlets. The peripheral portion has at least one step for controlling a density of the plasma formed by the electrode. The electrode can be used as the grounded upper electrode in a parallel plate plasma processing apparatus such as a plasma etching apparatus. The geometric features of the step and of a corresponding edge ring on the lower electrode can be varied to achieve the desired etch rate profile across a wafer surface.

Description

technical field [0001] The present invention relates generally to methods of etching using high energy radiation or plasma, and more particularly to a method and apparatus for controlling the etch rate at the edge of a wafer during the manufacture of integrated semiconductor circuits. Background technique [0002] Since the mid-1960s, integrated semiconductor circuits have gradually become the main components of most electronic systems. These miniaturized electronic devices can contain thousands of transistors and other circuits that make up the memory and logic subsystems of a microcomputer's central processing unit. The low cost, high reliability, and speed of operation of these computer chips have made them a ubiquitous feature of modern digital electronics. [0003] The fabrication process of integrated circuit chips typically begins with a thin, polished slice of a substrate of high-purity, single-crystal semiconductor material called a "wafer." Each wafer undergoes a...

AI Technical Summary

Problems solved by technology

Therefore, the use of conventional parallel plate reactors during plasma etch reduces the etch rate near the edge of the substrate being processed

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