sp3 Diamond Technologies, Inc., a leading supplier of diamond film products, equipment and services, today announced it is taking orders for 2-inch and 4-inch silicon on diamond (SOD) wafers for use as Gallium Nitride (GaN) substrates and accelerating development of 6-inch wafers for use as laterally diffused metal oxide semiconductor (LDMOS) substrates. sp3’s SOD wafers deliver higher thermal conductivity at a lower cost than existing silicon carbide (SiC) alternatives for GaN and for higher performance LDMOS devices because of improved thermal conductivity over traditional silicon wafers.
sp3’s SOD wafers deliver a high performance path for devices designed for WiMax base stations and other commercial and military broadband and high power switching applications. This would include radar communications equipment, weather and communications satellite equipment and hybrid power switching devices. sp3’s new offering seeks to address the current performance limitations of these devices, as they become increasingly impacted by the thermal restrictions of silicon wafers or the extreme cost and lower performance of SiC wafers.
“High-power, high-frequency devices – such as high power radar and RF amplifiers, and DC to DC and AC to DC converters – have performance limitations due to the physical structure of standard silicon substrates,” said Dwain Aidala, president and COO of sp3 Diamond Technologies. “Military and industrial applications stand to benefit significantly from building devices on a diamond substrate with a device quality, thin silicon top layer. GaN or LDMOS devices built on such a structured substrate can be driven to significantly higher power levels than current alternatives, thereby maximizing performance. sp3’s SOD wafers deliver industry-leading performance, are scalable up to 300 mm and are available at a lower cost than alternative diamond-based solutions or traditional SiC substrates.”
The SOD wafers are delivered as structured substrates with a top layer of device-quality float-zone silicon. They provide diamond heat spreading directly under the junction and can achieve more than a 100 percent increase in power levels compared to silicon substrates alone, and a 50-80 percent increase when compared to SiC, at a fixed junction temperature. At fixed power, they can reduce junction temperature by more than 50 degrees compared to GaN on silicon or SiC. GaN growth on SOD yields epi films equivalent to GaN on silicon, and sp3 can scale wafer size up to 300 mm.
2-inch and 4-inch SOD wafers with a silicon top layer are currently available for GaN devices, as well as with a GaN epitaxial layer (GaN on SOD wafers) for those manufacturers without an epitaxial deposition capability in-house. Lead-time and pricing are dependent on volume; interested customers should contact [email protected] for more information.