A GaN LED structure with a short period superlattice digital contacting layer
is
provided. The LED structure comprises, from the bottom to top, a substrate, a double
buffer layer, an n-type GaN layer, a short period superlattice digital contacting
layer, an active layer, a p-type shielding layer, and a contacting layer. The feature
is to avoid the cracks or pin holes in the thick n-type GaN layer caused during
the fabrication of heavily doped (n11019cm-3)
thick n-type GaN contacting layer, so that the quality of the GaN contacting layer
is assured. In addition, by using short period heavily doped silicon Al1-x-yGaxInyN
(n++-Al1-x-yGaxInyN) to grow a superlattice
structure to become a short period superlattice digital contacting layer structure,
which is used as a low resistive n-type contacting layer in a GaInN/GaN MQW LED.
In the following steps, it is easier to form an n-type ohmic contacting layer,
and the overall electrical characteristics are improved. It also lowers the operating
voltage of the entire element so that the energy consumption during operation is
reduced and the yield rate is increased.