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A unique confined lateral selective epitaxial growth (CLSEG) [1] technique for next generation semiconductor devices was demonstrated in [2, 3] and termed template assisted selective epitaxy (TASE). This technique is based on the formation of hollow confined structures that drive subsequent growth initiation only from a small area of the substrate exposed to the growth environment, dubbed a seed, and continued growth is forced within the template. This allows to arbitrarily determine the shape and orientation of the grown material and to form novel nano-electronic device structures. Here, results are reported on the fabrication of channel-like nanometer sized horizontal structures, and, the subsequent homoepitaxy of indium phosphide (InP) to demonstrate the potential for TASE to create vertical heterojunctions that could enable the next generation of tunnel field-effect transistors (TFETs) [4]. Templates were fabricated with a combination of e-beam lithography, PECVD deposition, resist patterning, and selective wet etches, on (100) n-type InP wafers. Homoepitaxy was done via MOVPE achieving growth selectivity with a growth temperature of 640°C, group III precursor molar rate of 4E-6 mol/min, a V/III ratio of 400. Trimethylindium (TMIn) and tertiarybutylphosphine (TBP) are used as indium and phosphorus precursors respectively. Characterization via scanning electron microscopy (SEM) and transmission electron microscopy (TEM) was employed to determine the success of growth in the template, initiation at the “seed”, area selectivity, faceting at the growth front, and conformality to the template. Each die consisted in a parametric array of structures of varying characteristic sizes that allows, via growth-interrupt trials, to analyze confined growth behavior and how this deviates from bulk epitaxy. Initial data suggests growth rate suppression with increased channel length. MOVPE in these conditions is known to be mass transport limited [5], so this could be explained with the need for the precursors to diffusively cover longer distances.