High Performance Electron Cyclotron Resonance Plasma Etching with Control of Magnetic Field Gradient

It is shown that high-performance Electron Cyclotron Resonance (ECR) plasma (hyper-ECR) is effective as a dry etching technique for fabrication of VLSI devices. The gradient of the magnetic field is one of the most important parameters for a uniform high etch rate. The Si etch rate and the ion current density can rise with decreasing magnetic field gradient. The high uniformity of the etch rate is achieved with highly uniform distribution of the magnetic field gradient. The density distribution of plasma is also improved by the hyper-ECR, so the drift instability is stabilized and a no-microloading etching process is produced.