Influence of rapid thermal annealing at varied temperatures on conductivity activation energy and,structural properties of Si-doped β-Ga2O3 film grown by pulsed laser deposition

Si-doped beta-Ga2O3 was generally activated by high-temperature annealing (over 600 degrees C) due to its strong bonding energy. Considering the electronic applications using beta-Ga2O3 such as various power devices with low power consumption, it is strongly required to decrease the device process temperature including the impurity activation process. In this article, in order to decrease the impurity activation process temperature, we proposed the rapid thermal annealing (RTA) treatment to activate the Si atoms in the beta-Ga2O3 films since RTA treatment can give the high thermal energy to specimen in a short time and investigated the influence of RTA treatment with various temperatures on conductivity activation energy, and structural properties of Si-doped beta-Ga2O3 film. Si-doped beta-Ga2O3 films were hetero-epitaxially grown on c-plane sapphire substrate by pulsed laser deposition method. Crystallinity, surface roughness, and electrical properties of specimens were investigated by changing the RTA temperatures. Crystallinity and surface roughness of Si-doped beta-Ga2O3 films were not significantly influenced by RTA treatment at temperatures range of 100-700 degrees C. Conductivity activation energy of specimens with RTA treatment was about 50-100 meV and did not depend on RTA temperatures. As a result, even Si-doped beta-Ga2O3 film with RTA treatment at 100 degrees C showed a relatively good conductivity. Based on the experimental results in this study, it can be said that RTA treatment is useful method to decrease the temperature of activation process for Si-doped beta-Ga2O3 thin films without serious structural degradations.