Abstract:
Compared to the well-mastered blue-green range, the formation of InGaN-based structures that effectively emit and are photosensitive in the red and infrared wavelength ranges is a difficult task for existing growth technologies. Lowering the growth temperature is the main way to increase the In content in the InGaN solution and reduce composition fluctuations, but this can lead to degradation of the crystalline quality and radiative properties of the resulting layers. In the MBE PA method, in addition to temperature, the growth processes can be significantly influenced by changing the stoichiometric ratios of the different InGaN components. In this paper, we study the effect of growth temperature, the ratio of fluxes of III and V group elements on the formation features of planar structures with InGaN layers, their structural perfection and radiative properties in the red wavelength range. It is found that under growth conditions close to stoichiometric, a decrease in the growth temperature to 575$^\circ$C allows increasing the efficiency of In incorporation and increasing its content in InGaN to 39%. However, in this case, composition fluctuations in the InGaN layers increase significantly, and the surface roughness and density of growing dislocations grow. It is demonstrated that at high growth temperatures of $\sim$605$^\circ$C, an increase in the In flux compensating for its desorption from the growth surface allows obtaining a homogeneous InGaN layer with an In content of up to $\sim$33.5% and smooth surface.
Fulltext:
PDF file (703 kB)