Process for making semiconductor devices

Claim 1

IN THE PROCESS OF MAKING A SEMICONDUCTOR DEVICE HAVING A P-N JUNCTION PORTION WITH PREDETERMINED TUNNEL DIODE CHARACTERISTICS, THE STEPS COMPRISING PREPARING THE DEVICE WITH THE P-N JUNCTION PORTION PROCESSED TO PROVIDE THE TUNNEL CHARACTERISTICS IN A DEGREE LESS THAN OPTIMALLY POSSIBLE, THERE BEING LEADS ATTACHED TO EACH SIDE OF SAID P-N JUNCTION; APPLYING TO THE PORTION A CHEMICAL ETCHANT EQUIVALENT TO THAT PRODUCED BY ADMIXING THE FOLLOWING COMPONENTS BY VOLUME FROM 1 TO 10 PARTS OF FUMING RED NITRIC ACID (90%), FROM 1 TO 15 PARTS OF ACETIC ACID (80%), FROM 1 TO 10 ML. OF HYDROFLUORIC ACID (50% HF) AND FROM 0.1 TO 4 ML. OF BROMINE PER 100 ML. OF SOLUTION; PASSING A FORWARD CURRENT THROUGH THE LEADS TO THE P-N JUNCTION AS ETCHING PROGRESSES TO MEASURE SUBSTANTIALLY CONTINUOUSLY THE PEAK-TO-VALLEY CURRENT RATIO AT THE JUNCTION WITHOUT REMOVING THE DEVICE FROM CONTACT WITH THE ETCHANT AND CONTINUING ETCHING UNTIL THE DESIRED PEAK-TO-VALLEY CURRENT RATIO AT THE JUNCTION IS ATTAINED.