Independent thesis Advanced level (degree of Master (Two Years)), 20 credits / 30 HE credits
In this work growth of cubic GaN in the selective area (SA) MOVPE process is
simulated. The simulations are restricted to small pattern SA MOVPE growth.
In this case the traditional MOVPE growth and the enhanced growth caused by
surface diffusion are important growth factors. The lateral vapor phase diffusion
is ignored while this process only has a small impact on the enhanced growth in
the small pattern SA growth. The model is build for simulation of anisotropic
growth. It has been shown that different type of anisotropic growth occurs when
the mask pattern are orientated in different directions on the substrate. While
the anisotropic growth is not well understood two different models are studied in
The simulation is restricted to the geometrical growth characteristics such
as mask and crystal width, mask alignment and surface diffusion on the crystal.
The reactor geometry, pressure and growth temperature are not investigated that
closely and are only treated as constants in the model.
The model used in this simulation gives good results for short time simulations
for some certain cases. The model shows that the fill factor has a greater
impact on the grown shapes than the individual mask and crystal width. But
there are problems with the anisotropic and flux from mask modeling while some
facets do not appear and the lateral growth along the mask show doubtful results.
The model show good results in short time growth and predict some important
characteristics in SA MOVPE.
2009. , 62 p.