OPTICAL COMMUNICATIONS.

THE GROWTH OF GAAS ON SILICON HAS LONG BEEN RECOGNIZED AS A DESIRABLE APPROACH FOR ADVANCE OPTOELECTRONIC DEVICES INCLUDING OPTICAL INTEGRATED CIRCUITS, OPTICAL COMMUNICATIONBETWEEN CIRCUITS AND AS A SOURCE OF LOW-COST GAAS LAYERS FORSOLAR CELL AND DISPLAY APPLICATIONS. PROGRESS ON THE DEVELOPMENT OF THIS TECHNOLOGY HAS BEEN AFFECTED BY STRAINS AND DISLOCATIONS INTRODUCED INTO THE GAAS LAYER BY THE LATTICE MISMATCH BETWEEN THE TWO MATERIALS. WE PROPOSE TO VIRTUALLY ELIMINATE THE DELETERIOUS EFFECT OF THE LATTICE MISMATCH THROUGH THE USE OF A NOVEL STRUCTURE WHICH MINIMIZES THE CONTACT AREA BETWEEN THE GAAS AND THE SILICON.THIS STRUCTURE IS FORMED BY GROWING A SILICON DIOXIDE LAYER ON THE SILICON AND THEN OPENING SMALL HOLES IN THE OXIDE USING PHOTOLITHOGRAPHY. THESE HOLES WILL BE TWO TO FIVE MICRONS IN DIAMETER AND WILL HAVE TWENTY TO FIFTY MICRON SPACING GAAS WILL BE GROWN FROM SATURATED SOLUTIONS. THE HOLES IN THE OXIDE WILL SERVE AS NUCLEATION CENTERS LEADING TO SINGLE CRYSTAL GROWTH. LATERAL OVER-GROWTH OF THE OXIDE CAN BE ENHANCED BY CHOOSING THE PROPER SUBSTRATE ORIENTATION, I.E. . DIRECT CONTACT BETWEEN THE SILICONAND THE GAAS WILL BE LESS THAN ONE PERCENT OF THE AREA WHICHWILL LIMIT STRAIN AND DISLOCATION PROPAGATION THROUGH THE GROWN GAAS FILM.