Reactive Ion Beam Etching Using a Broad Beam ECR Ion Source

Abstract

A broad beam ion source using a microwave electron cyclotron resonance (ECR) discharge has been newly developed, giving high reliability in operation. The ion source operates at gas pressures higher than about 3×10^-5 Torr, and an ion current density of 1 mA/cm² is obtained at an ion extraction voltage of 1000 V. By introducing C₄F₈ and SiCl₄ into the ion source, SiO₂ and Al are etched at rates greater than 1000 Å/min, with high selectivities and high-accuracy pattern transfer.