pairs are separated by the field perpendicular to the surface of the ccd and only the electrons are collected in the well under the phase 4 electrode 58 the holes flow either to the bulk or to the silicon silicon dioxide interface depending on the type of the ccd structure and the location of their creation the generated holes usually do not further participate in the multiplication process the multiplication therefore involves only a single carrier which is known to be an inherently low noise process after all the careers have transferred through the high field region and multiplied it is now possible to proceed with their transfer to the next stage this is accomplished by biasing the phase 1 electrode 52 high and the phase 4 electrode 58 low followed by biasing the phase 2 electrode 54 high and the phase 1 electrode 52 back low to its original level the careers now reside in the temporary storage well of the next stage and are ready for the next multiplication this is initiated by biasing the phase 4 electrode 58 high and injecting the charge again over the potential barrier under the phase 3 electrode 56 from the fig3 it can be also observed that it.