Fast switching diodes

Claim 1

A FAST SWITCHING P-N JUNCTION SEMICONDUCTOR DIODE HAVING A BODY OF MONOCRYSTALLINE SEMICONDUCTOR MATERIAL COMPRISING A FIRST REGION CONTAINING A FIRST EXTRINSIC CONDUCTIVITY TYPE DETERMINING IMPURITY ESTABLISHING A FIRST VALUE OF RESISTIVITY THROUGHOUT A FIRST PORTION OF ITS VOLUME, SAID RESISTIVITY INCREASING TO A MAXIMUM AT THE JUNCTION, AND A SECOND REGION OF OPPOSITE EXTRINSIC CONDUCTIVITY TYPE SEMICONDUCTOR MATERIAL CONTIGUOUS WITH SAID FIRST REGION AND ESTABLISHING THE P-N JUNCTION WHEREIN THE IMPURITY CONCENTRATION FIRST INCREASES AND THEN DECREASES WITH INCREASING DISTANCE FROM THE JUNCTION AND THEN DECREASES WITH INCREASING DISTANCE FROM THE JUNCTION AFTER A MAXIMUM POINT JUST OUTSIDE OF THE TRANSISTOR REGION FOR SETTING UP A DRIFT FIELD THEREIN TO SWEEP INJECTED EXCESS MINORITY CARRIERS AWAY FROM THE JUNCTION WHEN THE DEVICE IS REVERSE BIASED AND WHEREIN THE IMPURITY CONCENTRATION OF THE SECOND REGION LEVELS OFF AT A POINT REMOVED FROM SAID MAXIMUM TO ESTABLISH AN OVERALL RESISTIVITY IN SAID SECOND REGION OF AT LEAST FIVE TIMES THE OVERALL RESISTIVITY OF THE FIRST REGION.