This rapidly causes the antifuse to short out the blown bulb, allowing the series circuit to resume functioning, albeit with a larger proportion of the mains voltage now applied to each of the remaining lamps.
Formation of the conductive channel is performed by a dielectric breakdown forced by a high-voltage pulse.
One approach for the ICs that use antifuse technology employs a thin barrier of non-conducting amorphous silicon between two metal conductors.
When a sufficiently high voltage is applied across the amorphous silicon it is turned into a polycrystalline silicon-metal alloy with a low resistance, which is conductive.
Amorphous silicon is a material usually not used in either bipolar or CMOS processes and requires an additional manufacturing step.
At temperatures above 100 °C and current densities above 105 A/cm2 the metallization undergoes electromigration and forms spikes through the junction, shorting it out; this process is known as Zener zap in the industry.
Zener zap is frequently employed in mixed-signal circuits for trimming values of analog components.
It is therefore necessary to shift the manufacturing tolerances so that the lowest-value typically made is equal to or larger than the desired value.
When the failed lamp was finally replaced, a new piece of film was also installed, again separating the electrical contacts in the cutout.
This style of street lighting was recognizable by the large porcelain insulator that separated the lamp and reflector from the light's mounting arm; the insulator was necessary because the two contacts in the lamp's base may have routinely operated at a potential of several thousands of volts above ground/earth.