Carona PL imaging

PL with Corona charging

Deposition of a corona charge generated by the application of a high voltage (kV range) to
an air gap between the voltage source and Si sample can be used for a number of different
purposes, including:

1) Modulation of surface passivation quality, providing information about
inversion/accumulation properties of surface dielectrics as well as stored charge
within a dielectric.

2) Manipulation of high diffusivity charged interstitial impurities within Si wafers (the
main focus currently at UNSW is the control of Cu diffusion with surface corona
charge).

The system developed at UNSW is capable of deposition of full-area surface charge of both
positive and negative polarities on the surface of Si wafers, as well as the potential for
tracking lifetime with in-situ PL. The tool itself is currently under development with only
basic functionality (deposition of stored charge – no in-situ lifetime/PL information can be
obtained at the current stage).