VERTICAL STRAINED LAYER SUPERLATTICE FOR HIGH SPEED OPTOELECTRONICS

OPTO/ELECTRONIC DEVICES ONE ATOM IN SIZE ARE THE ULTIMATE LIMIT. AN ARRAY OF SUCH DEVICES HAS MAXIMUM POSSIBLE DENSITY AND SPEED. THAT'S OUR AIM. OUR APPROACH - YOU HAVE A FLIGHT OF STAIRS, AND A SUPPLY OF RED AND GREEN BALLS. YOU DROP THE BALLS, AND SOMEHOW RED ONES COLLECT ON ODD-NUMBERED STAIRS, AND GREEN ONES ON EVEN STAIRS. SUBSEQUENT BALLS LINE UP ON THEIR RESPECTIVE COLOR, BUILDING WALLS OF DIFFERENT COLORED BALLS, IN AN ALTERNATING PATTERN. WE USE CHEMICAL VAPOR DEPOSITION TO CATCH ATOMS ON THE NATURALLY OCCURING 25-ATOM-WIDE STEPS OF A SEMICONDUCTOR SURFACE. ARRIVING ATOMS TEND TO COLLECT FIRST IN STEP CORNERS, AND SPREAD TOWARDS THE EDGE. CAREFUL CONTROL OF OUR GROWTH PROCESS PLACES ALL "BALLS" INTO THEIR PROPER SITES. INITIAL RESULTS INDICATE IT MAY ACTUALLY WORK. SUPERLATTICES, (THIN ALTERNATING HORIZONTAL LAYERS) HELPED REVOLUTIONIZE OPTO/ELECTRONICS IN THE 80'S; VERTICAL SUPERLATTICES ARE THE "NEXT" FRONTIER. QUANTUM-EFFECT DEVICES WILL RESULT. PHYSICISTS ARE HAVING A FIELD DAY THINKING UP WAYS TO USE ALL THESE NEW POSSIBILITIES.