FLAAT Growth Technology for Low-Cost, Thick, High-Quality GaN on 6¿ Sapphire with No Wafer Bow

The use of non-native substrates for GaN-based devices leads to devices with high densities of defects stemming from misfit dislocation formation due to lattice mismatch and large values of wafer bow stemming from thermal mismatch. The latter is particularly problematic as one attempts to grow device films on large area substrates. The high defect densities give rise to degraded performance and reliability, while the wafer bow can be problematic to device fabrication as well as to growth of e.g. InGaN at lower temperatures than underlying buffer layer temperatures, reducing device yields. 6. General statement of how this problem is being addressed: The technology proposed utilizes HVPE films grown on an engineered substrate. 7. What was done in Phase I and Phase II? We have demonstrated the FLAAT concept using 2”, 4”, and 6” substrates and have demonstrated the engineered substrate under Phase II. LED device results on groups of 6” wafers showed >90% yields in a production setting. We have also designed various components which will be utilized on the production HPVE tool to improve throughput, uptime, diameter scalability, and reduce cost. 8. What is planned for the Phase II project? The Phase IIB project asks to build the prototype production tool. 9. Commercial Applications and Other Benefits: The technology can provide the quality of freestanding GaN at the cost of a GaN template so many types of devices can be impacted by the availability of the FLAAT templates. We have funding and purchasing commitments from two major LED manufacturers and envision the technology being adopted by power electronics manufacturers as well.