Gallium compounds with reduced silicon contamination and a method of manufacturing them

Abstract

Abstract THIS INVENTION RELATES TO A METHOD OF MANUFCTURING GALLIUM COMPOUNDS SUCH AS GAAS, GAP, GA1X-XINXAS, GA1-XALXAS, GAAS1-XPX AND GA1-XINXP, WITH A REDUCED LEVEL OF SILICON CONTAMINATION, X BEING A NUMBER RANGING FROM 0 TO 1, INCLUSIVE OF 0 AND EXCLUSIVE OF 1, AND GALLIUM COMPOUND CRYSTALS PREPARED BY THE METHOD. THE METHOD COMPRISES SUCH A STEP THAT WHEN MANUFACTURING A GALLIUM COMPOUND IN A SEALED FUSED SILICA REACTION TUBE, AT LEAST ONE OF SILICON, A SILICON COMPOUND, BORON, A BORON COMPOUND, ALUMINUM AND AN ALUMINUM COMPOUND IS ADDED INTO THE VESSEL SUPPORTING THE MELT OF THE COMPOUND, PARTICULARLY THE FUSED SILICA VESSEL, AND AT THE SAME TIME OXYGEN OR A METALLIC OXIDE WHICH IS UNSTABLE AT THE TEMPERATURE OF THE FURNACE AND WHICH CAN FORM A GALLOUS OXIDE (GA2O) ATMOSPHERE IS ADDED INTO THE SEALED FUSED SILICA REACTION TUBE, WHEREBY SILICON IN THE MELT IS REMOVED AND A THIN FILM OF A STABLE OXIDE IS FORMED AROUND THE MELT TO SUPPRESS SILICON CONTAMINATION FOR A LONG TIME. THE VAPOR OF GALLOUS OXIDE REDUCES THE CONCENTRATION OF FREE SILICON IN THE MELT, WHILE THE FILM OF A STABLE OXIDE AROUND THE MELT REMARKABLY REDUCES THE FREE SPACE WHERE GALLOUS OXIDE CAN BE FRESHLY PRODUCED, SILICON CONTAMINATION BEING THUS SUPPRESSED FOR A LONG TIME. BESIDES FOR THE REDUCTION OF SILICON CONTAMINATION, THIS METHOD CAN FURTHER BE USED FOR THE DOPING WITH AN IMPURITY OTHER THAN SILICON.

Inventors

• 👤 Shinichi Akai
• 👤 Takashi Shimoda

Bibliographic Details