The growth of aluminium nitride thin films and investigation of their microstructures

In this thesis, the microstructures of aluminium nitride thin films which were grown on borosilicate glass at different substrate temperatures (50oC, 150oC and 250oC) have been examined by using reactive RF magnetron sputtering. It was observed that the microstructure of films consisted of arbitrary oriented worm-like grains, micro holes and heaps. It was seen that as substrate temperature increased, the size of worm-like grains increased and the spaces between grains decreased. For each substrate temperature the size of heaps observed in grown film morphology was measured. Especially in the case of 50oC and 250oC substrate temperatures, an increase in the number and size of heaps was observed which was an indication on structure defect in the film morphology. Information on the nucleation mechanism of worm-like grains was obtained from SEM images gathered during and the effect of temperature on grains was examined by measuring the size of grains. Elements that create thin film composition were investigated using EDX analysis. In conclusion AIN thin films growth was carried out successfully and it was determined that there might had occurred a secondary phase in the film morphology as aluminium oxide.