Plasma-immersion ion implantation

Plasma-immersion ion implantation (PIII)[1] or pulsed-plasma doping (pulsed PIII) is a surface modification technique of extracting the accelerated ions from the plasma by applying a high voltage pulsed DC or pure DC power supply and targeting them into a suitable substrate or electrode with a semiconductor wafer placed over it, so as to implant it with suitable dopants.

The sample holder is connected to a high voltage power supply and is electrically insulated from the chamber wall.

The plasma sheath expands until either a steady-state condition is reached, which is called Child Langmuir law limit; or the high voltage is switched off as in the case of Pulsed DC biasing.

Here the same theory applies as previously discussed, but with a difference that the extracted ions from the grid holes bombard the substrate, thus causing implantation.

In this sense a triode type PIII implanter is a crude version of ion implantation because it does not contain plethora of components like ion beam steering, beam focusing, additional grid accelerators etc.