Metalorganic vapour phase epitaxy (MOVPE) has proven to be a successful method for growth of structures for advanced optoelectronic semiconductor devices in III-V compounds. This thesis deals with technological and process related aspects of MOVPE from an experimental perspective. Special attention is given to three main questions: uniformity over large areas, p-type dopant diffusion and redistribution in structures for heterostructure bipolar transistors, and planar embedding of high mesas for buried heterostructure lasers.

A uniformity within a few per cents for thickness, alloy composition, and dopant incorporation over large areas is fundamental for growth of advanced device structures. We present a new horizontal reactor with a large width-to-height aspect ratio operating at reduced pressure, and with a rotating susceptor for single wafers with a diameter of up to 75 mm. The obtained uniformity over 40 mm diameter is within  1 % for thickness, composition and doping, and within   1 nm for the wavelength of quaternary InGaAsP at  = 1560 nm. The doping distribution has been used to estimate the tempera­ture gradient over the wafer to a few tenths of a degree, and the uniformity is most probably limited by gas phase diffusion and depletion of the reactants.

Abrupt doping profiles are important for some devices. An example is the high frequency performance of the n-p-n heterostructure bipolar transistor (HBT), which is improved by a very narrow and highly doped p-type base. We have compared Zn and Mg for this application. The memory effect of Mg in the reactor gives doping tails towards the surface, but with Zn we obtained an abruptness of three decades over 60 nm at a maximum doping level exceeding 21019 cm-3. However, a highly n-doped layer of AlGaAs adjacent to the Zn-doped region gives rise to a significant re-distribution of Zn into the AlGaAs layer. At a reduced growth temperature this effect is diminished and the maximum doping level is simultaneously increased.

Growth on partly masked and non-planar substrates has become an impor­tant field for realisation of devices designed in three dimensions. We have fo­cused on planar regrowth of semi-insulating InP around high mesas of buried heterostructure lasers. Unwanted growth over the masked mesa top usually occurs. These depositions are reduced at high growth temperatures and for growth around low mesas (< 2 m). Addition of CCl4 in the MOVPE process considerably improves the morphology, especially for growth around high mesas. When chlorine is provided to the growing surface nucleation is pre­vented on the phosphorus-faced {111}B lattice planes and the mask, and this effect per­mits reproducible planar regrowth not limited by the mesa height.