Popis: |
Shallow diffusions of zinc in GaP epitaxial layers were carried out varying the positions on the Ga-P-Zn phase diagram. Under special diffusion conditions zinc profiles were obtained as predicted by the subsitutional-interstitial theory in which the gallium vacancy equilibrium at the diffusion front is maintained. Otherwise, a tail was found in zinc profiles at concentrations below 5·1016 cm−3 not reported till now in GaP epitaxial layers. It is demonstrated that the degradation behaviour of green-emitting diodes is determined by the occurence of zinc diffusion tails in the active zone. |