Designs using the as-grown epitaxial reflector 304 may be most effective in LEDs with small aspect ratios and reflecting sidewalls (e.g., the reflecting n-type electrode 406. Even when the micro-cavity is not formed, the EL emission may be incident on the epitaxial reflector 304 over a relatively narrow range of angles and its reflectivity at large angles of incidence may not be important. It should be noted the bottom surface of the substrate 202 may be roughened or patterned to improve extraction of green PL emission that passes through the epitaxial reflector 304.

Referring now to FIG. 5, a chart illustrating reflectivity of the epitaxial reflector 304 over different angles of incidence for different wavelengths of light is shown.

The wafer fabrication processing may be similar as that of a conventional single-wavelength LED and may include conventional steps such as chemical cleaning, acceptor activation anneal, dry etching of mesas, and deposition of metal contacts, passivation and isolation layers. A deeper mesa etch may be required due to the increased thickness of epitaxial material between the p-type layer 208 and the highly doped n-type layer 204 due to the addition of PL emitting QWs that are not part of a standard LED structure.

The deposition of the reflecting p-type electrode 402 on the p-type layer 208 may be similar as in a conventional LED process flow. For example, as described above, an opaque metal that has a high reflectivity across the visible and near-ultraviolet spectrum (e.g., Ag) may be evaporated or sputtered onto the surface of p-type layer 208.