November 28, 2007 – Sharp Manufacturing Systems has created a wafer cleaning system that uses hot, concentrated ozone water with sustained high concentrations to more effectively dissolve and remove photoresist and other organic contaminants, according to the Nikkei Business Daily.
Typical ozone-water removal methods, used as a gentler cleaner than sulfuric acid (which also costs chipmakers more than 10B yen/~$90M annually), oxidizes and dissolves unwanted on-wafer compounds, with ozone concentration of 75ppm in 80 degree C water (the higher the temperature, the lower the concentration). But the company has figured out how to vary the pressure to prevent the ozone concentration from declining during heating, which improves the ozone concentration by nearly 50% to 110ppm at 80 degrees C.
The technology is being combined with other equipment into a cleaning system, to sell for around 50M yen (US ~$460K), the paper noted. Sharp Manufacturing hopes to sell 10 units next year, and 70 by 2010.