U.S. Department of Energy - Energy Efficiency and Renewable Energy
Building Technologies Office – R&D Projects
Ultratech Develops an Improved Lithography Tool for LED Wafer Manufacturing
Ultratech's adapted lithography tool lowers the manufacturing cost of high-brightness LEDs.
Ultratech modified an existing lithography tool used for semiconductor manufacturing to better meet the cost and performance targets of the high-brightness LED manufacturing industry. The goal was to make the equipment compatible with the wide range of substrate diameters and thicknesses prevalent in the industry while reducing the capital cost and the overall cost of ownership (COO).
The tool was designed for the semiconductor industry and uses projection lithography, which is more cost-effective than the usual alternative, proximity print lithography. While proximity print lithography is fine for R&D and low-volume manufacturing, it is not suitable for mass production.
A recent comparison between the new tool—which Ultratech is already marketing to the industry—and conventional contact lithography based on the operation of two parallel manufacturing lines at a commercial wafer fabrication facility demonstrated very significant benefits—up to 30 percent more device output, a tenfold decrease in the re-work rate, and a 7 percent increase in final yields, with capital expense reduced by almost 30 percent.
Using patterned sapphire substrate structures that were fabricated with the Ultratech lithography tool, major LED manufacturers have reported an increase in LED output efficiency of 15–20 percent. The tool was proven to achieve a return on investment in only three to six months.