Production HVPE Technology for GaN-based electronics
Summary:
TDI has taken an existing wafer-growing process called hydride vapor phase epitaxy (HVPE) and improved the quality of the wafers it produces while increasing output levels to more than a dozen 2-inch wafers at one time. This is an important increase in throughput because gallium and aluminum nitrides cannot be grown in boules as easily as silicon and other semiconductor materials can. TDI is selling these wafers and using it’s reactors in-house to fill orders.
Technology Description:
The hydride vapor phase epitaxy (HVPE) process is straightforward chemistry. When producing gallium nitride (GaN), hydrochloric acid gas is passed over a bowl of molten gallium, which reacts with the gas to form gallium chloride gas. The gallium chloride flows into a chamber where it meets the sapphire substrates and ammonia gas. The ammonia reacts with the gallium chloride forming the GaN, which condenses on the substrate. TDI uses the same basic process to also produce aluminum nitride on either sapphire or silicon carbide, and it also can be used to produce aluminum gallium nitride either on sapphire or silicon carbide. Aluminum nitrides allow the manufacture of UV-emitting LEDs and laser diodes.
HVPE is cheaper, faster, and simpler that metal organic chemical-vapor deposition (MOCVD) because the HVPE reactor does not require a vacuum. HVPE uses less expensive and dangerous chemical precursors, and it deposits material faster than MOCVD. MOCVD deposits between 1 and 2 microns of wide-bandgap semiconductor material per hour and HVPE deposits the material up to 100 times faster. HVPE is capable of producing much thicker layers with lower defects.
MDA Origins:
TDI’s work for the MDA has been to improve purity and decrease costs for manufacturing wide-bandgap semiconductors, which the missile defense community would use for high-frequency, high-power electronics, or as light sources for optical communications. TDI first received BMD funding in 1998 for other wide-bandgap semiconductor research and since then, they have received at least five additional Phase I SBIRs, and three Phase II SBIRs related to HVPE wafer growth. The company is currently completing a Phase II SBIR.
Spinoff Applications:
TDI has improved HVPE so that is it can be used for mass production by cutting the technique’s costs and increasing product quality. This can cut costs and production time for electronics manufacturers, and could make TDI a major supplier of wafers. The company could also sell the reactors but is currently pursuing selling wafers only.
Lower cost wafers will reduce both military and commercial research costs as well as the cost of producing finished electronic components. Lower costs could enable new uses for GaN and AlN, such as cost-effective, architectural white LED lighting and cheaper UV lasers for next-generation DVDs. Low defect HVPE layers open novel device design possibilities.
GaN or AlN on silicon carbide may be excellent new substrates for high electron mobility transistors (HEMT) and amplifiers because the SiC substrate is a very good thermal conductor as is AlN. This market may be of importance to MDA.
TDI’s ability to make large-diameter wafers up to 6 inches in diameter could allow manufacturers to further cut costs during fabrication. By basing their fabrication lines on larger wafers, manufacturers can produce more components per unit of time. Previously, 4 inches was the largest diameter of GaN wafers made.
Commercialization:
TDI has more than 100 customers including universities, government labs, and companies around the world. Customers receive wafers made to the specifications they provide TDI. The company indicated they had recently received an order for GaN wafers from a Taiwanese LED manufacturer.
The company estimates that 70 percent of the GaN, AlN, and AlGaN wafer market is in optoelectronics, and the remaining 30 percent is in high-frequency, high-power electronics. Currently, the optoelectronics market is more mature, and high-frequency, high-power electronics manufacturers are just starting to make products. Therefore, TDI must convince current makers of LEDs and diode lasers to switch from their in-house MOCVD systems to having the wafers made by TDI. For microwave communications, radar, and power system electronics makers, TDI positioning to save researchers time and money now and provide low defect wafers for manufacturers that may be starting up in the near future.
TDI has over 20 patents on its technology with some information remaining as trade secrets. Costs for large volumes of GaN on sapphire have decreased from $1,000 to around $100 per wafer. Dr. Vladimir Dmitriev, president and founder of TDI, said, “This program has resulted in a substantial price reduction for these materials, no question.” TDI may still face competition from other makers of semiconductor wafers such as Sumitomo Electric (Japan).
Company Profile:
TDI is an employee-owned company with no outside investors. The company generates revenue from selling wafers to electronic component manufacturers and researching technology for government customers.
Contact Information:
Dr. Vladimir Dmitriev
Technologies and Devices International
12214 Plum Orchard Dr
Silver Spring, MD 20904
(301) 572-7834
fax: (301) 572-6435
email: vladimir@tdii.com
web: www.tdii.com
|