A NONINVASIVE TEMPERATURE SENSOR FOR PLASMA PROCESSING OF SEMICONDUCTORS

THE PROJECT IS DEVELOPING A NONINVASIVE TEMPERATURE SESNOR FOR APPLICATION IN DRY ETCHING (PLASMA ETCHING, REACTIVE ION ETCHING, FOR EXAMPLE) OF ELECTRONIC MATERIALS. THERE IS A CRITICAL NEED FOR SUCH SENSORS AT PRESENT SINCE THE TEMPERATURE OF THE WAFER INFLUENCES THE RESULTS OF THE ETCHING PROCESS; ETCH RATE, UNDERCUTTING, AND SURFACE QUALITY. IN ADDITION , THE PHOTORESIST USED FOR MASKING BEGINS TO CHAR AT ELEVATED TEMPERATURES. HENCE, IT IS IMPORTANT TO MEASURE AND MONITOR THE WAFER TEMPERATURE AT ALL TIMES. THE RESEARCH EFFORT WILL RESULT IN A NOVEL TEMPERATURE SENSOR TO MEASURE AND MNITOR WAFER TEMPERATURE IN DRY ETCHING ENVIRONMENT. THE INNOVATION IS THAT THE TECHNIQUE WILL ENABLE A NONINVSIVE, CONTACTLESS, AND NON-DESTRUCTIVE METHOD OF PERFORMING SURFACE TEMPERATURE MEASUREMENT IN A PLASMA ETCHING CHAMBER. IN CONTRAST, EXISTING TECHNIQUES ARE INVASIVE AND CUMBERSOME AND THE NEED FOR CONTACTING PRECLUDES MEASURING THE PROCESS-WAFER TEMPERATURE; INSTEAD ONLY THE TEMPERATURE OF THE CATHODE OR A DUMMY WAFER IS MEASURED AT PRESENT. SCIENTIFIC RESEARCH ASSOCIATES, INC. ARE INVESTIGATING PHOTOREFLECTANCE AS A TEMPERATURE SENSOR FOR THE ABOVE PURPOSE. THE ENERGY GAP OF THE SEMICONDUCTOR MATERIAL WILL BE MEASURED USING MODULATION SPECTROSCOPY AND CORRELATED TO THE SURFACE TEMPERATURE. THE EFFORT WILL DEMONSTRATE THE FEASIBILITY AND ACCURACY OF THIS TECHNIQUE.