NIST spin-off provides new twist on debug, trace cutting and adding metal connections at advanced nodes.
Focused ion beam (FIB) circuit editing is an enabling technology that has been around for some time. Using a standard FIB tool, a chipmaker can basically edit portions of a circuit before it goes into production. It allows chipmakers to debug chips, cut traces, add metal connections and perform other functions.
One startup, zeroK NanoTech, is putting a new and innovative twist on FIB circuit edit tool technology for advanced nodes.
“Almost all of the focused ion beams sold today use the same ion source. It’s called a gallium liquid metal ion source. It works well for most applications,” said Adam Steele, a co-founder of zeroK NanoTech, based in Gaithersburg, Md. “But circuit pitches continue to shrink. As they do, the precision of the focused ion beam needs to be higher. There is demand for a higher precision focused ion beam. Our innovation is improving the performance of the source of ions in the focused ion beam.”
In fact, zeroK NanoTech is developing a so-called Low Temperature Ion Source (LoTIS) technology for use in FIB-based circuit edit applications. The company’s ion source is based on cesium. Generally, cesium is an alkali metal with a melting point of 28° Celsius. This makes it one of a few elemental metals that are liquid at or near room temperature.
Meanwhile, zeroK NanoTech’s roots can be traced to the National Institute of Standards and Technology (NIST), an agency of the U.S. Department of Commerce. Steele and the company’s other co-founder, Brenton Knuffman, were post-doctoral students at NIST. At NIST, Steele and Knuffman were working on FIB-based circuit editing technology based on a cesium source.
Then, NIST moved to spinout the technology into a new company called zeroK NanoTech in 2011. The company licensed the technology from NIST. And in 2012, zeroK NanoTech was awarded a Small Business Innovation Research (SBIR) grant from the National Science Foundation (NSF).
The startup wasn’t officially up and running until 2013. At that time, zeroK NanoTech was awarded additional funds from the NSF as well as some capital from an undisclosed company.
Based on the technology from NIST, the company has developed a bench-top FIB circuit editing system. The idea behind circuit editing is relatively simple. “You drill down into the circuit using the focused ion beam to cut through insulator and metal layers. And you can make modifications to circuits directly,” Steele said. “This is advantageous because making a new mask to create a new prototype chip is quite expensive in both money and time. The focused ion beam is used to shorten the process moving from the prototype to the manufacturing stage. It cuts down on the number of masks that need to be made.”
The problem? The industry needs more precise circuit edits.
Looking to solve the problem, zeroK NanoTech has developed LoTIS. This technology creates a cold beam of atoms. The beam of atoms is then photoionized in an electric field, thereby creating a precise and cold ion beam.
“These are precisions that haven’t been achieved to date, at least with heavy ions, for doing these surface modifications,” Steele said. The company’s technology can be used in semiconductor, biotech, nanotechnology and other applications.
What’s next for zeroK NanoTech? The company continues to collaborate with NIST. “We have a bench-top model that has been tested and works,” he said. “The next key step is to build an alpha stage FIB tool.”
Clearly, though, the startup faces some challenges in moving to the next level. “The equipment industry is quite expensive. It is challenging to get the resources to have a startup and improve the hardware,” he said. “But if we could deliver, it would be of enormous use to the industry.”