Method of growing dislocation-free semiconductor crystals

Claim 1

THE METHOD OF GROWING LARGE OXYGEN-FREE DISLOCATION-FREE SINGLE CRYSTALS OF INORGANIC SEMICONDUCTIVE MATERIAL WHICH METHOD COMPRISES: PREPARING AN ELONGATED CYLINDRICAL SOLID SOURCE INGOT OF INORGANIC SEMICONDUCTIVE MATERIAL HAVING ESSENTIALLY THE SAME COMPOSITION DESIRED IN A SINGLE CRYSTAL, SAID SOLID SOURCE INGOT HAVING A DIAMETER THEREOF SUFFICIENT TO ALLOW THE GROWTH THEREFROM OF LARGE CRYSTALS; PROVIDING A SOLID TAPERED PORTION IN ONE END OF SAID SOLID SOURCE INGOT, SAID PORTION BEING TAPERED TO A SUBSTANTIALLY RESTRICTED DIAMETER AT SAID END OF THE INGOT, THE TAPERED PORTION HAVING A LENGTH GREATER THAN SAID DIAMETER OF SAID SOLID SOURCE INGOT, SAID SUBSTANTIALLY RESTRICTED DIAMETER BEING LARGE ENOUGH TO PROVIDE STABLE SUPPORT PRIMARILY BY SURFACE TENSION FOR A MOLTEN GLOBULE ATOP SAID TAPERED PORTION, AND SAID RESTRICTED DIAMETER BEING SMALL ENOUGH TO PERMIT A NEEDLE-LIKE SEED CRYSTAL TO BE BROUGHT INTO THERMAL EQUILIBRIUM WITH A MOLTEN GLOBULE SUPPORTED PRIMARILY BY SURFACE TENSION ATOP SAID TAPERED PORTION WITHOUT FREEZING SAID GLOBULE; SUSPENDING SAID INGOT WITHIN A TRANSPARENT REFRACTORY TUBULATION WHICH IS ONLY SLIGHTLY LARGER IN INSIDE DIAMETER THAN THE LARGEST OUTSIDE DIAMETER THEREOF WITH SAID TAPERED PORTION UPPERMOST; ESTABLISHING A CONCENTRATED RADIO FREQUENCY ELECTROMAGNETIC FIELD SUFFICIENT TO CAUSE THE MELTING OF SAID SEMICONDUCTIVE MATERIAL AT THE UPPER RESTRICTED DIAMETER END OF THE TAPERED PORTION OF SAID INGOT SO AS TO CAUSE SAID END TO MELT; REGULATING THE STRENGTH OF SAID ELECTROMAGNETIC FIELD TO CAUSE A MOLTEN DROPLET OF SAID SEMICONDUCTIVE MATERIAL TO BE SUSPENDED BY SURFACE TENSION UPON THE UPPER END OF SAID BODY WHILE INSERTING THEREIN A VERY THIN NEEDLE-LIKE SEED CRYSTAL OF THE SAME SEMICONDUCTIVE MATERIAL; AND GROWING A DISLOCATED-FREE OXYGENFREE MONOCRYSTALLINE INGOT OF SEMICONDUCTIVE MATERIAL HAVING A VERY LARGE DIAMETER AS COMPARED WITH SAID SEED CRYSTAL FROM SAID MOLTEN DROPLET BY SEED CRYSTAL WITHDRAWAL WHILE REPLENISHING SAID DROPLET BY FURTHER MELTING SAID INGOT.

Claim 2

THE METHOD OF GROWING LARGE OXYGEN-FREE DISLOCATION-FREE SINGLE CRYSTALS OF INORGANIC SEMICONDUCTIVE MATERIAL WHICH METHOD COMPRISES: PREPARING AN ELONGATED CYLINDRICAL SOLID SOURCE INGOT OF INORGANIC SEMICONDUCTIVE MATERIAL HAVING ESSENTIALLY THE SAME COMPOSITION DESIRED IN A SINGLE CRYSTAL, SAID SOLID SOURCE INGOT HAVING A DIAMETER THEREOF SUFFICIENT TO ALLOW THE GROWTH THEREFROM OF LARGE CRYSTALS; PROVIDING A SOLID TAPERED PORTION IN ONE END OF SAID SOLID SOURCE INGOT, SAID PORTION BEING TAPERED TO A SUBSTANTIALLY RESTRICTED DIAMETER AT SAID END OF THE INGOT, THE TAPERED PORTION HAVING A LENGTH GREATER THAN SAID DIAMETER OF SAID SOLID SOURCE INGOT, SAID SUBSTANTIALLY RESTRICTED DIAMETER BEING LARGE ENOUGH TO PROVIDE STABLE SUPPORT PRIMARILY BY SURFACE TENSION FOR A MOLTEN GLOBULE ATOP SAID TAPERED PORTION, AND SAID RESTRICTED DIAMETER BEING SMALL ENOUGH TO PERMIT A NEEDLE-LIKE SEED CRYSTAL TO BE BROUGHT INTO THERMAL EQUILIBRIUM WITH A MOLTEN GLOBULE SUPPORTED PRIMARILY BY SURFACE TENSION ATOP SAID TAPERED PORTION WITHOUT FREEZING SAID GLOBULE; SUSPENDING SAID INGOT WITHIN A TRANSPARENT REFRACTORY TUBULATION WHICH IS ONLY SLIGHTLY LARGER IN INSIDE DIAMETER THAN THE LARGEST OUTSIDE DIAMETER THEREOF WITH SAID TAPERED PORTION UPPERMOST; ESTABLISHING A CONCENTRATED RADIO FREQUENCY ELECTROMAGNETIC FIELD SUFFICIENT TO CAUSE THE MELTING OF SAID SEMICONDUCTIVE MATERIAL AT THE UPPER RESTRICTED DIAMETER END OF THE TAPERED PORTION OF SAID INGOT SO AS TO CAUSE SAID END TO MELT; REGULATING THE STRENGTH OF SAID ELECTROMAGNETIC FIELD TO CAUSE A MOLTEN DROPLET OF SAID SEMICONDUCTIVE MATERIAL TO BE SUSPENDED BY SURFACE TENSION UPON THE UPPER END OF SAID BODY WHILE INSERTING THEREIN A VERY THIN NEEDLE-LIKE SEED CRYSTAL OF THE SAME SEMICONDUCTIVE MATERIAL; AND GROWING A DISLOCATED-FREE OXYGENFREE MONOCRYSTALLINE INGOT OF SEMICONDUCTIVE MATERIAL HAVING A VERY LARGE DIAMETER AS COMPARED WITH SAID SEED CRYSTAL FROM SAID MOLTEN DROPLET BY SEED CRYSTAL WITHDRAWAL WHILE REPLENISHING SAID DROPLET BY FURTHER MELTING SAID INGOT.