Diode structure in semiconductor integrated circuit and method of making the same

Claim 1

IN A SEMICONDUCTOR INTEGRATED CIRCUIT, THE STRUCTURE COMPRISING: A FIRST PORTION FOR PROVIDING DIODE FUNCTIONS AND A SECOND PORTION FOR PROVIDING TRANSISTOR FUNCTIONS; EACH OF SAID PORTIONS COMPRISING AN ISOLATE REGION OF SEMICONDUCTIVE MATERIAL OF A FIRST TYPE OF SEMICONDUCTIVITY; SAID FIRST PORTION HAVING A FIRST REGION OF SECOND TYPE SEMICONDUCTOR THEREIN THAT ENCLOSES AND UNDERLIES A SUB-PORTION OF SAID ISOLATED REGION SO THAT THE JUNCTION BETWEEN SAID FIRST REGION AND SAID SUB-PORTION IS CAPABLE OF OPERATING AS A DIODE JUNCTION HAVING A RELATIVELY HIGH BREAKDOWN VOLTAGE, THE JUNCTION BETWEEN THE INNER PERIPHERY OF SAID FIRST REGION AND SAID SUB-PORTION OF SAID ISOLATED REGION BEING GREATER THAN A CARRIER DIFFUSION LENGTH FROM THE JUNCTION AT THE OUTER PERIPHERY; SAID SECOND PORTION HAVING A SECOND REGION OF SAID SECOND TYPE THAT EXTENDS THEREIN TO APPROXIMATELY THE SAME DEPTH AS SAID INNER PERIPHERY OF SAID FIRST REGION AND A THIRD REGION OF SAID FIRST TYPE DISPOSED IN SAID SECOND REGION TO FORM A TRANSISTOR STRUCTURE, SAID SUB-PORTION OF SAID ISOLATED REGION HAVING A LOWER IMPURITY CONCENTATION THAN SAID THIRD REGION.