RF ION SOURCE FOR REACTIVE ION BEAM ETCHING

A VARIETY OF DRY ETCHING PROCESSES HAVE BEEN DEVELOPED FOR USE IN THE MANUFACTURE OF HIGH SPEED, HIGH DENSITY, INTEGRATED SEMICONDUCTOR CIRCUITS. THE RECENT REQUIREMENTS FOR SUBMICRON FEATURE DIMENSIONS HAVE PLACED STRESSING DEMANDS ON EXISTING TECHNOLOGIES SUCH AS REACTIVE ION ETCHING AND INERT ION BEAM ETCHING. REACTIVE ION BEAM ETCHING (RIBE) HAS RECENTLY BEEN DEMONSTRATED TO OFFER ADVANTAGES RELATIVE TO THESE TECHNOLOGIES BY FACILITATING RAPID ETCHING WITH HIGHLY PRECISE, SUBMICRON PATTERN DEFINITION. HOWEVER, AVAILABLE ION BEAM SOURCE DESIGNS INCORPORATE THERMIONIC ELECTRON EMITTERS WHICH ARE EASILY DAMAGED BY THE GASES USED IN RIBE PROCESSING. THIS RESULTS IN SHORT ION SOURCE LIFETIME, THEREBY GREATLY LIMITING THE PRACTICAL APPLICATION OF RIBE. PULSE SCIENCES, INC. PROPOSES TO OVERCOME THIS PROBLEM BY DEVELOPING AN INEXPENSIVE RADIO FREQUENCY (RF) ON SOURCE WHICH IS EXPECTED TO BE INSENSITIVE TO REACTIVE GASES AND THEIR PRODUCTS. AN EXPERIMENTAL, 20-30 CM, MAGNETIC-FIELD-FREE, RF ION SOURCE SYSTEM WILL BE CONSTRUCTED WHICH INCORPORATES A COLD CATHODE DISCHARGE IGNITER. PLASMA GENERATION EXPERIMENTS WILL BE PERFORMED WITH O2 AND CCL4 GASES AT RF FREQUENCIES UP TO 13.56 MHZ. ION EMISSION UNIFORMITY WILL BE MEASURED AND OPTIMIZED AT A CURRENT DENSITY OF APPROXIMATELY 1 MA/CM2 WITH THE GOAL OF ACHIEVING LESS THAN 5% VARIATION OVER THE CORE OF THE BEAM.