Bottom-up Scalable Epitaxial Growth of Gallium Oxide with Integrated Thermal Management for Next-Gen Electronics

The objective of this proposed work is to develop the knowledge base for large scale epitaxial growth of b-Ga2O3.á The key developments proposed here that will lead to the desired result of industrially scalable manufacturing of b-Ga2O3.á Our proposed effort uses two commercial MOCVD system for epitaxy which can be controlled to grow the thinner layers with specific doping profiles for lateral devices, and thicker layers for vertical devices.á Both growers will produce these device structures and fabricate exemplary device structures in both cases so that all users can reproducibly produce world class materials and record device metrics.á Epitaxial growth is the key to this effort, but other factors besides the deposition parameters are important for the reproducibility and repeatability that is necessary for a scalable manufacturing process.á Substrate defects have been a source of non-reproducibility and reduced performance in previous compound semiconductor systems.á In many cases, extensive government programs were used to develop substrates for InP and SiC, for example.á Once substrate defect issues were identified and addressed in those systems, device and circuit production performance and yields increased tremendously.á Here, a task of relating substrate defects due to the substrate formation as well as damage due to substrate polishing will be assessed in terms of their impact on electrical performance.á Damage-free polishing and cataloguing certain defects to a specific device parameter (leakage current, for example) will further advance the ability of the technical community to produce high quality material and high-performance devices.á Along with these efforts, both (010) and (001) oriented wafer surfaces will be assessed for the propensity to form defects. A detrimental aspect of b-Ga2O3 is its inability to conduct heat well.á Furthermore, the low symmetry of the Ga2O3 crystal ensures that the non-uniform heat dissipation will prevail, so achieving a solution to effective heat dissipation at the substrate level is crucial.á A major thrust of this effort and one that stands out from other efforts is the development of a composite wafer using ion-based exfoliation processes.á Based on work in the team to successfully exfoliate uniform mm-thick films of the full wafer diameter onto high thermal conductivity substrates, our effort will include developing such wafers for the eventual widespread use for b-Ga2O3 epitaxial layers.á The thermal boundary conductance associated with these structures will allow b-Ga2O3 to operate under higher power conditions with higher performance than is currently available.á This effort aims to stands up the effort at AMD to evolve into a major player in this and other aspects of materials integration.á This will occur through the development of the gallium oxide on different substrate method to produce these structures at costs more typical of standard wafers.á á