Mechanisms in Plasma Etching

Very little will be said here concerning the equipment aspects of plasma etching. There are three basic types of equipment which have been used a) barrel systems, b) planar systems, and c) systems in which the wafers are located downstream from the plasma to be referred to in this paper as downstream etching systems. These plasma etching configurations are shown schematically in Fig. 3.1. Often the barrel systems are used with a perforated metal tube called an etch tunnel which is shown in Fig. 3.1 a and b. The purpose of the etch tunnel is to protect the wafers from the energetic ion and electron bombardment to which waters immersed directly 

Extent of Ion Bombardment Inert Gas Discharge Reactive Gas Discharge  

Minimal (Sample on Ground Plane) Plasma Cleaning Plasma Anodization (Oxygen plasma) Plasma Etching Plasma Ashing (Oxygen plasma) 

Extensive (Sample on Target Electrode) Sputter Etching Reactive Sputter Etching Reactive Sputter Etching Reactive Ion Etching 

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