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

Abstract

Si-doped β-Ga2O3 was generally activated by high-temperature annealing (over 600 °C) due to its strong bonding energy. Considering the electronic applications using β-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 β-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 β-Ga2O3 film. Si-doped β-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 β-Ga2O3 films were not significantly influenced by RTA treatment at temperatures range of 100–700 °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 β-Ga2O3 film with RTA treatment at 100 °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 β-Ga2O3 thin films without serious structural degradations.