Thin multi-well active layer led with controlled oxygen doping

Abstract

An LED and a method of fabricating the LED which utilize controlled oxygen (O) doping to form at least one layer of the LED having an O dopant concentration which is correlated to the dominant emission wavelength of the LED. The O dopant concentration is regulated to be higher when the LED has been configured to have a longer dominant emission wavelength. Since the dominant emission wavelength is dependent on the composition of the active layer(s) of the LED, the O dopant concentration in the layer is related to the composition of the active layer(s). The controlled O doping improves the reliability while minimizing any light output penalty due to the introduction of O dopants. In an exemplary embodiment, the LED is an AlGaInP LED that includes a substrate, an optional distributed Bragg reflector layer, an n-type confining layer, an optional n-type set-back layer, an active region, an optional p-type set-back layer, a p-type confining layer and an optional window layer. In a preferred embodiment, the active region includes a multiplicity of active layers, where each active layer is 125 Angstroms thick or less and the active layers are separated from each other by barrier layers whose composition is Al In P and whose thickness is 100 Angstroms or less. In a preferred embodiment, both the p-type confining layer and the p-type set-back layer are doped with a controlled amount of O, depending on the dominant emission wavelength of the LED. In addition to the O doping, the p-type confining layer of the LED is preferably doped with a high amount of p-type dopants, such as Mg, Zn, C or Be. During high temperature thermal processing, this high concentration of p-type dopants then partially diffuses into the active region, resulting in a heavily p-type doped active region.