GAAS VERTICAL AND LATERAL GROWTH ENHANCEMENT USING TRIMETHYLGALLIUM AND TRIMETHYLARSENIC IN SELECTIVE-AREA METALORGANIC VAPOR-PHASE EPITAXY ON A (111)B SUBSTRATE

We propose that the desorption of arsenic trimers from the 2x2 reconstructed (111)B surface governs the growth GaAs (111)B for large V/III ratio and high temperature. The measured activation energy of the trimer desorption is 13 kcal/mol in the AsH3/TMG case. The growth rate on a (110) substrate is independent of the V/III ratio. In contrast, lateral growth enhancement of the (110) facets is observed on (111)B patterned substrates for large V/III ratios and/or high growth temperature. This strongly suggests that the reduction of the number of Ga species reacting on the slow-growing (111)B facet at large AsH3 flux is the main mechanism involved in the enhancement of the (110) side-wall growth.