Etchant gases header
Many SIAD gases are used in the etching process.
Etchant gases include fluorocarbons and other fluorinated materials.
The most important gases today are halocarbon 14, halocarbon 23, halocarbon 116, and nitrogen trifluoride. These etchant gases react with silicon, silicon dioxide and silicon nitride.
Halocarbons are used typically to etch silicon compounds, whereas the other chlorine and fluorine compounds are usually required for etching metallic interconnects.
The choice of gas strongly depends on the ability of a given mixture of gases to selectively etch one film in the presence of another with a sufficient degree of profile control.