To increase the lattice constant of AlInGaP LED layers to greater than the
lattice constant of GaAs for reduced temperature sensitivity, an
engineered growth layer is formed over a substrate, where the growth
layer has a lattice constant equal to or approximately equal to that of
the desired AlInGaP layers. In one embodiment, a graded InGaAs or InGaP
layer is grown over a GaAs substrate. The amount of indium is increased
during growth of the layer such that the final lattice constant is equal
to that of the desired AlInGaP active layer. In another embodiment, a
very thin InGaP, InGaAs, or AlInGaP layer is grown on a GaAs substrate,
where the InGaP, InGaAs, or AlInGaP layer is strained (compressed). The
InGaP, InGaAs, or AlInGaP thin layer is then delaminated from the GaAs
and relaxed, causing the lattice constant of the thin layer to increase
to the lattice constant of the desired overlying AlInGaP LED layers. The
LED layers are then grown over the thin InGaP, InGaAs, or AlInGaP layer.