Gas injection system for etching profile control

Abstract

A gas injection system provided in a plasma etching equipment is provided. The system includes a top gas injector for supplying a reaction gas at a top of a chamber, and a side gas injector for supplying a tuning gas from a side surface of the chamber or a backside gas injector upward jetting a tuning gas from a lower side of a wafer. The side gas injector or backside gas injector forms a plurality of jets in a radial shape and simultaneously installs the jets adjacently to an edge part of a wafer such that a tuning gas is jetted adjacently to the edge part of the wafer, thereby being capable of easily controlling a an etch rate or CD uniformity or profile of the edge part.

Description

CROSS REFERENCE[0001]This application claims foreign priority under Paris Convention and 35 U.S.C. §119 to Korean Patent Application No. 10-2010-0015999, filed Feb. 23, 2010 with the Korean Intellectual Property Office.BACKGROUND OF THE INVENTION[0002]1. Field of the Invention[0003]The present invention relates to a gas injection system provided in a plasma etching equipment. More particularly, the present invention relates to a gas injection system for etching profile control, for jetting a tuning gas adjacently to an edge part of a wafer for a user to precisely control an etch rate or a Critical Dimension (CD) uniformity and profile in the edge part, thereby being capable of improving an etching uniformity through uniform formation of a Critical Dimension (CD) and profile of the whole wafer and minimizing a process failure.[0004]2. Description of the Related Art[0005]Generally, an ultra-fine circuit or pattern of a desired is formed on a surface of a large-diameter wafer used for ...

AI Technical Summary

Benefits of technology

[0016]An aspect of exemplary embodiments of the present invention is to address at least the problems and / or disadvantages and to provide at least the advantages described below. Accordingly, an aspect of exemplary embodiments of the present invention is to jet a tuning gas for plasma control adjacently to an edge part of a wafer, thereby optimizing a jet effect through the minimization of a tuning gas diffusion phenomenon and effectively controlling a CD uniformity or profile of the edge part of the wafer.

[0017]Another aspect of exemplary embodiments of the present invention is to effectively compensate an etch rate and CD difference between a center part and edge part of a wafer by installing a plurality of tuning gas jets along the edge part of the wafer in a radial shape and uniformly jetting a tuning gas to the whole edge part of the wafer.

[0018]A further aspect of exemplary embodiments of the present invention is to minimize a process failure by effectively removing a reaction by-product such as polymer generated in an edge part of a wafer and also removing organic materials, foreign materials or the like attached to an outer side surface or lower part of the edge part.

[0019]A yet another aspect of exemplary embodiments of the present invention is to remarkably improving a chip yield of an edge part by not only reducing a process time through a rapid and uniform diffusion and plasma control but also guaranteeing an etching uniformity in the whole surface of a wafer.

Problems solved by technology

However, there was a problem that a chip yield of an edge part is remarkably deteriorated because etch rates of a center part and outer part (i.e., edge part) of a wafer are generally different from each other and CD uniformity or profiles are differently formed.

Firstly, regarding controlling a temperature of a wafer, in a case where high power is used as in an oxide film etching process (i.e., an oxide process), a CD control effect due to temperature control is unsatisfied.

Secondly, regarding dividing a showerhead into inner and outer parts or additionally supplying a O2 gas to a wafer, in a case where a chamber volume is large like an etching device making use of a high-density Inductively Coupled Plasma (ICP) source, a spaced distance between a gas supply unit and a wafer edge part is large, so it is difficult to precisely control the distribution of plasma by a difference of gas diffusion generated in a process in which a reaction gas or O2 gas reaches a wafer edge part and also, the CD control effect is greatly degraded and thus an etching uniformity of the edge part cannot be guaranteed.

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