When we design a deposition system or an effusion source, we simulate the flux distribution at the sample position. This allows us to optimize the crucible shape and chamber geometry for best performance of the system.
Whether you want to retrofit a source to your existing system or need an epitaxy chamber tailored exactly to your needs, we can investigate different approaches and alternatives beforehand without the need to manufacture prototypes.
The flux simulations allow us to minimize thickness nonuniformity by adapting the shape of the crucible as well as material consumption by choosing the best working distance and deposition direction. We have developed a highly optimized algorithm that is fast and accurate at the same time, allowing us to investigate entire parameter fields while keeping the simulation times short.
The figures show an example simulation of a large volume source pointing at the sample at an angle of 30? from a distance of 216 mm. The flux distribution is calculated on an area 200?200 mm. The simulations show the deposited material thickness for a non-rotating and rotating sample. The sample diameter of 60 mm is indicated by the red circle. In the non-rotating case there is an almost linear thickness gradient across the sample that could be employed for combinatorial materials science approaches. On a rotating sample, the thickness is quite uniform at the simulated filling level of the source. Color and the black contour lines indicate the height profile of the data, blue and green lines mark the positions of the line profiles shown in the diagrams.
The simulations can be performed for practically arbitrary source and sample geometries ranging in size from millimeters to meters.