Superfine IC geometries: Gas-plasma etching may supplant chemical etching in manufacturing high-performance integrated circuits

The advantages that dry etching offers over conventional chemical etching of integrated circuits are discussed. The underlying principle of dry etching is explained, and the various dry etching techniques in current use are described. The way in which voltage is created between plasma and wafer is explained, together with the mechanisms that produce directional etching. Attenuation is then given to the ability to operate over a wide pressure range and to monitoring based on light emission and DC bias. The dangers posed by overetching and energetic ions are discussed. Finally, the prospect of using expert systems in dry etching is assessed.