Advances in Large Diameter GaN on Diamond Substrates

摘要

The use of diamond or silicon on diamond (SOD) as a thermal heat spreader substrate for GaN high power transistor and solid state lighting devices has been demonstrated previously with active devices on a small scale but not at wafer sizes of 50 to 100 mm. The capability to reduce heat has been demonstrated but the benefits of this for large volume applications such as Wimax or commercial lighting require that the technology be scaled to much larger wafer sizes. This paper will highlight recent advances in scaling GaN on SOD wafers to 100 mm diameters and will report on the electrical characterization of GaN HEMT devices fabricated on 100 mm SOD wafers. Results will include whole wafer parametric data which illustrate the large area viability and consistency of the process as well as physical characterization showing the consistency of the structure across the wafer. In addition, it will discuss yield issues related to these larger diameter substrates including film stress, wafer thinning, and packaging.