Abstract: After a circuit is completely configured, including the mounting of semiconducting material onto a conductive layer and the connection of a conductor lead from a dot on the semiconducting material to the circuit, the required backdiode e/i characteristic is obtained by subjecting the whole circuit assembly to etching processing. The entire circuit is immersed into an electrolytic solution for etching away the semiconducting material to form the fragile narrow neck of the backdiode, thereby obtaining the required backdiode characteristic while advantageously obtaining an irreducible minimum of parasitic reactances associated with the resultant backdiode. Subsequent handling of the fragile backdiode as a component has been avoided because it is advantageously fabricated "in situ" pre-joined and integrated with the other components of the desired electronic circuit.