Pressure-and temperature-controlled apparatus for large-scale production of crystals by the czochralski technique

Claim 1

A PRESSURE- AND TEMPERATURE-CONTROLLED APPARATUS ADAPTED FOR GROWING CRYSTALS BY THE CZOCHRALSKI TECHNIQUE, COMPRISING IN COMBINATION A. PRESSURE-TIGHT FURNACE MEANS PROVIDING AN ENCLOSURE DIFINING THEREIN A WORKING VOLUME THE ATMOSPHERE OF WHICH MAY BE VARIED WITH RESPECT TO TEMPERATURE AND TO PRESSURE FROM A VACUUM TO AT LEAST 100 ATMOSPHERES, SAID FURNACE MEANS BEING FORMED OF A MAIN CYLINDRICAL FURNACE HOUSING OF ESSENTIALLY CONSTANT DIAMETER THROUGHOUT HAVING A TOP SECTION AND BOTTOM FLANGE MEANS AND A FURNACE BASE MEMBER HAVING THE SAME INSIDE DIAMETER AS SAID MAIN FURNACE HOUSING AND BEING SEALABLE WITH SAID MAIN FURMACE HOUSING THROUGH MATING FLANGE MEANS TO LIMIT SAID ATMOSPHERE ESSENTIALLY TO SAID VOLUME; B. FURNACE SEALING MEANS ENGAGEABLE WITH SAID MATING FLANGE MEANS AND COMPRISING TWO SEMICIRCULAR, INTERNALLY GROOVED MEMBERS AND BOLT MEANS ADAPTED TO LOCK SAID GROOVED MEMBERS IN ENGAGED POSITION AROUND SAID MATING FLANGE MEANS; C. CRYSTAL-PULLING ROD MEANS EXTENDING FROM EXTERNAL OF SAID MAIN FURNACE HOUSING INTO SAID VOLUME AND MOVABLE THEREIN IN BOTH ROTATIONAL AND TRANSLATIONAL MODES D. CRYSTAL-PULLING ROD BEARING AND SEALING ASSEMBLY MEANS LOCATED IN SAID TOP SECTION OF SAID MAIN FURNACE HOUSING AND PROVIDING THE SOLE SEALING MEANS BETWEEN SAID CRYSTAL-PULLING ROD MEANS AND SAID PRESSURE-TIGHT FURNACE MEANS; E. ROTATIONAL AND TRANSLATION CRYSTAL-PULLING ROD DRIVING MEANS LOCATED EXTERNAL OF SAID PRESSURE-TIGHT FURNACE MEANS AND RIGIDLY MOUNTED ON SAID MAIN FURNACE HOUSING, SAID TRANSLATIONAL DRIVING MEANS INCLUDING MEANS TO SELECTIVELY DRIVE SAID RODS IN A SLOW CRYSTAL-GROWING MODE OR IN A RIPID-POSITIONING MODE;