TSMC & ITRI Develop Particle-Monitoring System to Boost Yields

TAIPEI — Taiwan’s Industrial Technology Research Institute (ITRI) and Taiwan Semiconductor Manufacturing Co., Ltd. (TSMC) have developed a new system to monitor particles in liquid solutions that can cause defects during the chip fabrication process.

The system, dubbed SuperSizer, measures particle sizes from 3nm to 1,000nm, expanding the range of current monitoring and inspection tools that have an upper limit of only 40nm. The system also measures the concentration of particles, helping reduce impurities and scratches on underlying layers and structures of a chip.

TSMC has used SuperSizer to monitor chemical-mechanical polishing (CMP) processes on a daily basis. The system has been demonstrated at TSMC to reduce defect rates and scratches in CMP processes and increase yields.

“In the last two or three years, due to the particle situation, TSMC had to shut down a whole production line for two or three days,” said Wei-En Fu, the principal researcher and head of ITRI’s Nano & Mechanical Measurement Laboratory, in an interview with EE Times. “As the technology node goes down to 10nm by next year or 2017, the killer particles will be less than 10nm. This tool is the only one that can measure such small particles in situ.”

While only a handful of chipmakers are looking at 10nm production, ITRI says that the SuperSizer can monitor a wide range of particle sizes for less advanced process technologies.

“Most chipmakers want to monitor particle sizes below 30nm or 20nm,” Fu said. The ITRI system can be adjusted to measure particles in that range, he said. “It can also measure particles in relatively low concentrations.”

The cost of one SuperSizer unit is about $730,000 depending on the types of functions the machine has. For a system that monitors pure water only, the price is about $450,000, Fu said.

The system can monitor as many as four types of slurries as well as water for cleaning.

ITRI, which owns the technology and related patents, can take orders to manufacture the product, but the research organization intends eventually to license the technology to a company in Taiwan for volume manufacturing.

The Nano & Mechanical Measurement Laboratory at ITRI has about four other projects underway related to the semiconductor industry including one that uses x-ray refractivity to measure film thickness as well as the development of instruments to measure the surface roughness of pads used in CMP processes and extreme ultraviolet (EUV) scattering to measure critical dimensions of chip features.

ITRI, one of the world’s largest government-funded technology R&D institutions, has other divisions that are developing technology in such areas as materials and optoelectronics for the semiconductor industry. TSMC and United Microelectronics Corp. (UMC), Taiwan’s largest chip foundries, were spun off from projects started at ITRI.

—Alan Patterson covers the semiconductor industry for EE Times. He is based in Taiwan.