High-speed damage-free contact hole etching using dual shower head microwave-excited high-density-plasma equipment

Dual shower head microwave-excited plasma etching equipment for separating the plasma-excited region from the etching process region has been developed. With the aim of realization of damage-free etching, the carrier activation of boron-doped p(+)-Si is investigated after plasma irradiation. The damage-free-etching mode in which holes do not deactivate was found. Contact holes are successfully etched using a Surface damage-free etching process consisting of high-speed etching mode and surface damage-free etching mode. The damage-free-etching mode consists of low-self-bias condition and a low etching gas flow rate as compared with the high-speed mode. For both modes, the etcher can maintain the process uniformity because the etcher can control self-bias voltages without changing other process parameters.