ANISOTROPIC ETCHING OF N(-POLYSILICON USING BEAM PLASMAS GENERATED BYGAS PUFF PLASMA SOURCES())

Generation of pulsed chlorine beam plasmas using a nozzle beam system generated from an electron cyclotron resonance (ECR) discharge plasma source with a high-speed gas puff valve (gas puff plasma source) has b een studied. Simulations of gas flow, and measurements of plasma param eters and their etching properties have also been discussed, comparing the experimental results with those of conventional ECR plasmas using an almost identical reactor. The time-averaged electron temperatures around a wafer were lower than those in the ECR plasmas for time-avera ged pressure of 0.1-2 mTorr. The instantaneous ion energy distribution s of the beam plasmas incident on the wafer had wider high-energy tail s than those in the ECR, plasmas. Thus, anisotropic etching profiles o f n(+)-polysilicon were obtained at the position of the wafer (B-z sim ilar to 200 G) where notching phenomena were observed in the ECR plasm as.