ADAPTIVE DIAGNOSTICS AND CONTROL OF THE PLASMA ETCHING PROCESS

A KEY AUTOMATION PROBLEM IN THE SEMICONDUCTOR MANUFACTURING AREA IS THE EFFICIENT HIGH-YIELD FABRICATION OF SEMICONDUCTOR CIRCUITS. PLASMA ETCHING IS THE KEY PROCESS BY WHICH DESIRED CIRCUITS ARE PATTERNED ON A SEMICONDUCTOR WAFER. AS PATTERN GEOMETRIES BECOME MORE INTRICATE IN THE SUBMICRON RANGE, ETCHING PROCESSES BECOME MORE COMPLEX. BECAUSE THE INTRACTABLE. SEMICONDUCTOR MANUFACTURERS TYPICALLY USE A TRIAL AND ERROR PROCEDURE TO REALIZE A REPEATABLE FABRICATION PROCESS THAT HAS ACCEPTABLE YIELD. THIS IS EXPENSIVE IN TIME AND MATERIAL. BETTER CONTROL AND INSTRUMENTATION TECHNIQUES THAT REMOVE THIS UNCERTAINTY IN ETCHING WILL HAVE A MAJOR IMPACT ON SEMICONDUCTOR MANUFACTURING AND INTEGRATED CIRCUIT FABRICATION. PROCESS MODELS OF THE COMPELX, TIME-VARYING NONLINEAR DYNAMICS OF THE PLASMA ETCHING PROCESS WILL BE ACHIEVED THROUGH NEURAL NETWORK BASED SYSTEM IDENTIFICATION AND INTEGRATED INTO A LEARNING-OPTIMAL CONTROL SYSTEM TO PROVIDE ADPATIVE NONLINEAR PROCESS CONTROL. NEURAL NETWORK STATE ESTIMATION TECHNIQUES WILL BE USED FOR ON-LINE MONITORING OF SPECTROSCOPIC PROCESS MEASURES TO PROVIDE A FAST, FAULT TOLERANT MEANS OF DETERMINING COMPOSITION OF THE SURFACE OR THE PLASMA IN REAL-TIME. THE NEURODYNE AND HONEYWELL TEAM WILL LEVERAGE RESEARCH PERFORMED UNDER THE SEMATECH ADVANCED EQUIPMENT CONTROL PROGRAM TO SUPPORT THIS EFFORT. ANTICIPATED BENEFITS: AS EXPRESSED IN AN ENCLOSED LETTER OF SUPPORT FROM SEMATECH, AUTOMATION OF THE PLASMA ETCHING PROCESS WILL HAVE A SIGNIFICANT IMPACT UPON COMMERCIAL AND MILITARY IC FABRICATION. ANTICIPATED MANUFACTURING APPLICATIONS OF THIS EFFORT AT HONEYWELL SSDC INCLUDE: HIGH DENSITY ARRAYS, ADVANCED PRESSURE SENSORS, SILICON ACCELEROMETERS, AND MICROMECHANICAL ACTUATORS AND MICROVALVES.