Selective area growth of InP by plasma assisted solid-source epitaxy

Complete selective area growth of InP could be achieved at standard molecular beam epitaxial growth temperatures by using solid source epitaxy with an additional hydrogen rf-plasma (27 MHz) excited in the reaction chamber. By optimization of the process parameters such as substrate temperature, plasma power, and phosphorus overpressure, mirror-like InP-layers with geometry independent growth rates were grown on SiN-patterned InP substrates without polycrystalline growth on the mask. Since selective growth is also possible in an argon plasma, we conclude that a physical desorption process is the mechanism for selective area growth in this plasma assisted epitaxy method. Furthermore, the selectivity can be controlled by a dc-bias of the substrate, which influences the mean energy of the impinging ions, thereby changing the desorption rate of atoms from the mask.