A method of making an organic light emitting device (OLED) is disclosed
wherein an inert insulating conformal smoothing layer is deposited over a
protruding structure. The smoothing layer is patterned to expose portions
of the structure underlying the smoothing layer and defining active
regions of the device. The inert smoothing layer is treated, preferably
by heat reflow, to taper the layer over the stepped edges of the
structure on the exposed portions. Additional layers are then deposited
over the smoothing layer and the exposed portions of the structure. The
smoothing layer blunts all underlying layer edges and provides sloped
edges wherever a step occurs from one layer to another. This effect
results in a homogeneous field across the pixel and the continuity in the
layers deposited after the photoresist layer.