Tip formation of micrometer scale GaAs pyramid structures grown by MOCVD

Relatively large pyramid structures with heights upto 15 μm were grown selectively by MOCVD. Lineair growth rates for the pyramid facets, independent of the size of the mask openings, were obtained by paying special attention to the mask design. Three low-index facets, (0 0 1), {0 1 1} and {1 1 1}B, bound the pyramid and all of them are able to define the pyramid tip geometry. From facet growth rates and pyramid geometry the combination of growth time and size of the mask opening for obtaining a pyramid with a sharp tip can be accurately calculated. [Copyright &y& Elsevier]