ATOMIC LAYER EPITAXY OF GALLIUM-ARSENIDE IN A ROTATING-DISK REACTOR

ATOMIC LAYER EPITAXY (ALE) IS A PROMISING GROWTH TECHNIQUE. THE ATTRACTIVENESS OF ALE FOR FUTURE DEVICE AND INTEGRATED CIRCUIT APPLICATIONS CAN BE UNDERSTOOD BY CONSIDERING SEVERAL DESIRABLE ATTRI-BUTES FOR EPITAXIAL GROWTH TECHNIQUES. THESE INCLUDE LOWER DEFECT DENSITY, IMPROVED UNIFORMITY OF THICKNESS AND DOPING, IMPROVED THICKNESS CONTROL, AND THE POSSIBILITY OF CONFORMAL EPITAXY. A MAJOR PROBLEM WITH PRESENT ALE METHODS IS LOW GROWTH RATE, WHICH IS SUBSTANTIALLY LESS THAN A MONOLAYER PER SECOND. THE FEASIBILITY IS BEINGDEMONSTRATED OF ALE GROWTH OF GALLIUM-ARSENIDE IN A ROTATING DISK GEO-METRY METALORGAIC CHEMICAL VAPOR DEPOSITION (MOCVD) REACTOR. THE PRO-PORTIONALITY OF GROWTH RATE TO ROTATION RATE IS BEING DEMONSTRATED. IT IS ANTICIPATED THAT THIS WOULD ALLOW THE FABRICATION OF STRUCTURES WHICH REQUIRE BOTH HIGH AND LOW GROWTH RATES IN A SINGLE SYSTEM WITHOUT MAJOR PERTURBATIONS DURING GROWTH. THIS IS PARTICULARLY IMPORTANTFOR STRUCTURES WHERE ABRUPT INTERFACES ARE NECESSARY AND YET HAVE SUBSTANTIAL TOTAL EPITAXIAL THICKNESS. THE DEMONSTRATION OF A SIGNIFICANT ENHANCED GROWTH RATE IS A REQUIREMENT FOR THE DEVELOPMENT OF PRACTICAL ALE-BASED MATERIALS AND DEVICE TECHNOLOGIES. SUCCESSFUL DEVELOPMENT OF THE TECHNIQUES FOR REPRODUCIBLE GROWING DEVICE-QUALITY GALLIUM-ARSENIDE BY ALE WOULD HAVE MAJOR IMPLICATIONS FOR A BROAD RANGE OF DEVICE APPLICATIONS INCLUDING SENSORS, HIGH-SPEED ELECTRONIC DEVICES AND INTEGRATED CIRCUIT DEVELOPMENT.