Method of manufacturing semiconductor crystals

Claim 1

IN THE MANUFACTURE OF JUNCTION-TYPE TRANSISTORS, DIODES, AND SIMILAR DEVEICES, THE METHOD OF PRODUCING A SEMI-CONDUCTOR CRYSTAL HAVING CONTIGUOUS ZONES OF N-TYPE AND P-TYPE CONDUCTIVITY COMPRISING THE FOLLOWING STEPS: HEATING A MASS COMPRISING A SEMI-CONDUCTOR ELEMENT, A DONOR MODIFIER, AND AN ACCEPTOR MODIFIER TO FORM A MELT, SAID DONOR MODIFIER EXHIBITING A CHARACTERISTIC VARIATION IN SEGREGATION FACTOR WITH CHANGES IN INTERFACE TEMPERATURE GRADIENT WHICH IS SUBSTANTIALLY DIFFERENT FROM THE CORRESPONDING CHARACTERISTIC VARIATION OF SAID ACCEPTOR MODIFIER; CRYSTALLIZING A PORTION OF SAID MELT AT PREDETERMINED RATES OF CRYSTALLIZATION AND INTERFACE VELOCITY WHILE MAINTAINING A PREDETERMINED INTERFACE TEMPERATURE GRADIENT TO PRODUCE A FIRST SEMI-CONDUCTIVE CRYSTAL ZONE IN WHICH A SELECTED ONE OF SAID MODIFIERS IS THE PREDOMINANT IMPURITY; AND SUBSEQUENTLY ALTERING SAID INTERFACE TEMPERATURE GRADIENT WHILE CONTINUING TO CRYSTALLIZE MATERIAL FROM SAID MELT AT APPROXIMATELY THE SAME RATES OF CRYSTALLIZATION AND INTERFACE VELOCITY TO PRODUCE A SECOND SEMICONDUCTIVE CRYSTAL ZONE, CONTIGUOUS WITH SAID FIRST ZONE, IN WHICH THE OTHER OF SAID MODIFIERS IS THE PREDOMINANT IMPURITY.