Simultaneous etching and monitoring of semiconductor bodies

Claim 1

THE METHOD OF ETCHING A SEMICONDUCTOR BODY HAVING A PN JUNCTION TO REMOVE SHORTENING MATERIAL FROM SAID JUNCTION AND SIMULTANEOUSLY MONITORING THE EFFECT OF THE ETCHING ON SAID BODY, WHICH METHOD COMPRISES THE STEPS OF IMMERSING AND MAINTAINING THE BODY IN AN ETCHING BATH IN SUCH A MANNER THAT THE JUNCTION IS IN CONTACT WITH THE ETCHANT, APPLYING A D.C. VOLTAGE OF A MAGNITUDE SUBSTANTIALLY EQUAL TO THE REVERSE BREAKDOWN VOLTAGE OF THE JUNCTION ACROSS SAID JUNCTION IN THE REVERSE DIRECTION TO ETCH THE BODY IN THE REGION OF SAID JUNCTION, SIMULTANEOUSLY APPLYING A SUBSTANTIALLY LOWER VOLTAGE , HIGH FREQUENCY A.C. SIGNAL ACROSS THE JUNCTION, THE FREQUENCY OF SAID SIGNAL BEING OF A VALUE SUCH THAT THE IONIC CARRIERS IN THE ETCHANT DO NOT RESPOND THERETO WHEREAS THE CARRIERS IN THE SEMICONDUCTOR BODY DO RESPOND THERETO, RECORDING THE HIGH FREQUENCY RESPONSE TO THE JUNCTION ON AN INDICATING MEANS, AND DISCONTINUING THE ETCHING ON OCCURRENCE OF A INDICATION OF A SHARP VOLTAGE BREAKDOWN IN THE REVERSE DIRECTION.

Claim 2

THE METHOD OF ETCHING A SEMICONDUCTOR BODY HAVING A PN JUNCTION TO REMOVE SHORTENING MATERIAL FROM SAID JUNCTION AND SIMULTANEOUSLY MONITORING THE EFFECT OF THE ETCHING ON SAID BODY, WHICH METHOD COMPRISES THE STEPS OF IMMERSING AND MAINTAINING THE BODY IN AN ETCHING BATH IN SUCH A MANNER THAT THE JUNCTION IS IN CONTACT WITH THE ETCHANT, APPLYING A D.C. VOLTAGE OF A MAGNITUDE SUBSTANTIALLY EQUAL TO THE REVERSE BREAKDOWN VOLTAGE OF THE JUNCTION ACROSS SAID JUNCTION IN THE REVERSE DIRECTION TO ETCH THE BODY IN THE REGION OF SAID JUNCTION, SIMULTANEOUSLY APPLYING A SUBSTANTIALLY LOWER VOLTAGE , HIGH FREQUENCY A.C. SIGNAL ACROSS THE JUNCTION, THE FREQUENCY OF SAID SIGNAL BEING OF A VALUE SUCH THAT THE IONIC CARRIERS IN THE ETCHANT DO NOT RESPOND THERETO WHEREAS THE CARRIERS IN THE SEMICONDUCTOR BODY DO RESPOND THERETO, RECORDING THE HIGH FREQUENCY RESPONSE TO THE JUNCTION ON AN INDICATING MEANS, AND DISCONTINUING THE ETCHING ON OCCURRENCE OF A INDICATION OF A SHARP VOLTAGE BREAKDOWN IN THE REVERSE DIRECTION.