TDI to ship 4-inch AlN-on-SiC by the end of the year
Technologies and Devices International claims to have fabricated a prototype 4-inch AlN-on-SiC semi-insulating substrate.
The Silver Spring, MD, firm plans to target makers of AlGaN/GaN HEMTs with the material when it begins pilot production of the wafers over the next few months.
And it is hoped that the switch to 4-inch material with the high thermal conductivity offered by SiC will speed the development and commercialization of wide-bandgap RF devices for emerging applications such as WiMAX connectivity by enabling manufacturers to use existing 4-inch processing lines.
CEO Vladimir Dmitriev explained that the prototype wafer was fabricated using TDI's stress-control technology and crystal-growing equipment developed specifically by the company to deposit thick, crack-free AlN films.
"Our customers have been asking for about 4-inch substrates from the very introduction of the first 2-inch AlN-on-SiC wafers three years ago," Dmitriev said.
"This new product will allow our customers to use existing 4-inch device manufacturing lines, reduce production costs and speed commercialization of GaN-based devices," continued the CEO. "We plan to start pilot production of 4-inch AlN-based substrates in a few months and make the first product shipments in the last quarter of 2006."
According to TDI, the combination of AlN with SiC provides good thermal conductivity with the exceptionally high intrinsic electrical resistivity of AlN. The thickness of the AlN film is said to be sufficient for the reliable insulation and low current leakage that are crucial for high-frequency devices such as GaN HEMTs.
While TDI has concentrated on this combination of materials, others such as Crystal IS are taking a different approach to producing native substrates by growing single-crystal AlN.
As recently as last month, Crystal IS said that it had produced the first single-crystal AlN at a diameter of 2 inches (see related story).
