Impact of silane flow on donor traps in MOCVD Grown Gallium Oxide

Optimizing Gallium Oxide growth conditions will allow better quality material to be used in high power devices. Ideal thin-film Gallium Oxide material improves upon the tradeoff relation between the breakdown voltage and the specific on resistance which results in better performance than ordinary silicon transistors due to Gallium Oxide’s ultra-wide bandgap of 4.8 eV. To improve upon growth parameters, defects within Gallium Oxide must be minimized or prevented. The 100 meV donor defect is a recently new defect detected within the material that currently has no known basis as to what causes its presence. The purpose of this experiment was to see whether increasing the silane flow concentration within the Metal Organic Chemical Vapor Deposition (MOCVD) growth process influences the presence of the 100 meV donor. Both Hall measurements and Thermal Admittance Spectroscopy (TAS) data were used in conjunction to uncover the results of the hypothesis. While some of the samples did have the 100 meV donor appear in the Hall data, there seems to be no systematic trend with the silane flow and the defect according to Hall Effect data. Furthermore, there was not clear evidence of the 100 meV donor in the TAS data, which is still under investigation.  The data may suggest no direct relation between Silane flow and the defect regardless of concentration used. An alternative origin for the 100 meV defect could lay in extrinsic impurities or a lattice defect within antisites or intersitials of the substrate, however, further testing is recommended to verify that no relationship between the silane flow concentration and the 100 meV donor exists.