AUTOMATED MBE PROCESS WITH REAL TIME SENSOR CONTROL

WE PROPOSE AN AUTOMATED MOLECULAR BEAM EPITAXY (MBE) PROCESS FOR REPRODUCTABLE GROWTH OF SEMICONDUCTOR DEVICE STRUCTURES. WE WILL APPLY RHEED AND THERMAL OSCILLATION TECHNIQUES TO CONTROL THE RATE ANDCOMPOSITION OF THE LAYERS AND TO ENSURE THAT THE GROWTH PROCEEDS UNDEROPTIMUM CONDITIONS. A MASS SPECTROMETER WILL BE USED TO CONTROL DOPANT INCORPORATION LEVELS. FLUXES FOR OPTIMUM GROWTH OF THE DIFFERENCT LAYERS ARE MATCHED BY FEEDBACK CONTROLLING AN ADJUSTABLE COLUMN V CRACKER SOURCE. VARIOUS SENSOR INPUT WILL BE USED BY A MICROPROCESSOR TO CONTROL OTHER PARAMETERS AS WELL. THE MBE TECHNIQUEHAS BEEN USED FOR PRODUCTION OF MANY HIGH PERFORMANCE SEMICONDUCTOR DEVICES. THE PROPOSED INVESTIGATION WILL BE PERFORMED IN A MBE SYSTEMTHAT HAS INCORPORATED SIGNIFICANT ADVANCES IN MACHINE DESIGN TO IMPROVE RELIABILITY AND MATERIAL YIELD. THE IMPROVEMENTS INCLUDE LARGE CAPACITY TAPERED EFFUSION CELL, TWO ZONE CELL HEATING, A MICROPROCESSOR CONTROLLED CRACKER SOURCE, AND LONG-LIFE (> 1 MILLION CYCLES) SHUTTERS. THIS AUTOMATED PROCESS CAN BE USED FOR PRODUCTION OF A VARIETY OF COMPOUNDS AND CAN BE APPLIED TO SOLID SOURCE AS WELL AS GAS SOURCE MBE.