NOVEL TOROIDAL ELECTRON CYCLOTRON RESONANCE REACTOR FOR SEMICONDUCTOR MATERIALS PROCESSING

A RESEARCH PROGRAM FOR A NOVEL ELECTRON CYCLOTRON RESONANCE (ECR) REACTOR FOR DRY ETCHING AND DEPOSITION IS PROPOSED. THE TOROIDAL ECR REACTOR (TECR) USES A UNIQUE MAGNETIC GEOMETRY WHICH OFFERS GREAT POTENTIAL BENEFITS; (1) GREATLY REDUCED EXPOSURE OF THE WAFER TO HIGH-ENERGY PHOTON RADIATION AND ASSOCIATED WAFER HEATING, (2) UNIFORMITY OF ETCHING OVER 8-INCH WAFERS WHILE MAINTAINING ETCHING RATES WHICH ARE COMPARABLE TO CONVENTIONAL ECR SOURCES (ON THE ORDER OF 1 MICRON/MINUTE), (3) THE ABILITY TO SEPARATE THE ION COMPOSITION FROM THAT OF THE NEUTRAL COMPOSITION STRIKING THE WAFER, AND (4) VERY DIRECTIONAL ION FLUXES THAT REDUCE PATTERN DEPENDENCIES IN THE ETCHING OF SUBMICRON FEATURES. THE DESIGN PERMITS THE SEPARATION OF THE GLOW DISCHARGE FROM THE WAFER BY USING MAGNETIC FIELD LINES TO GUIDE THE TRANSPORT OF ELECTRONS AND IONS TO THE WAFER. THE ETCHING UNIFORMITY ACROSS THE WAFER CAN BE ADJUSTED BY TRIMMING THE SOLENOIDAL MAGNETIC FIELD, AND THUS, CAN BE CONTROLLED INDEPENDENTLY OF THE PROCESS CHEMISTRY AND DISCHARGE KINETICS. IN PHASE I, THE BASIC PHYSICS OF THE REACTOR WILL BE MODELLED, A PROTOTYPE REACTOR BE DESIGNED AND ENGINEERING DRAWINGS PRODUCED. IN PHASE II, THE PROTOTYPE TECR REACTOR WILL BE CONSTRUCTED AND TESTED.