Maglen: Multi-Beam E-Beam Inspection

Wafer inspection, the science of finding defects on a wafer, is becoming more challenging and costly at each node. In fact, the ability to detect sub-30nm defects is challenging with today’s inspection tools, which are primarily based on two separate technologies—optical and e-beam.

In the inspection flow, chipmakers first use e-beam inspection, mainly for engineering analysis. E-beam is able to find the smallest defects, but the throughputs are too slow to put these tools into the production flow.

To boost the throughputs in e-beam inspection, the industry is working on a technology that makes use of multiple beams. In fact, Hermes, MultiBeam and Sematech are separately developing multi-beam e-beam inspection tools. The first tools from vendors could appear in late 2015 or early 2016.

One startup, Maglen, is also developing a multi-beam e-beam inspection tool technology. In fact, the Singaporean company is going against the odds on three fronts. First, Maglen is developing a tool technology at a time when startups are rare in the fab equipment industry. Second, few, if any, venture capital firms are investing in the fab tool industry, which is considered a mature business.

And third, there are no multi-beam e-beam inspection tools in the market today and for good reason: It’s a challenging technology. E-beam is a mature technology, but it’s prone to secondary electrons and other issues on the wafer.

Still, Maglen believes it has the right technology to overcome the challenges. “Our target is partial wafer inspection,” said Tony Luo, founder of Maglen.

The company is developing a modular, 2D multi-column array. The technology is based on a permanent magnet lens array, which enables resolutions down to 2nm. This differs from the conventional coil-based magnetic multi-column approach, which degrades the performance of the system, according to Maglen.

Luo founded Maglen in 2013. The company has strong ties to the National University of Singapore (NUS). “We are now supported by multi-million-dollar funding from NUS,” he said. With the funding, the company is developing a prototype system.