Abstract:
It is difficult to imagine the modern world without electronics. Cloud computing, mobile communication, big data, to name a few, rely on the continuous rapid advancement of IC manufacturing. To achieve new functionalities and to make optimum use of the available wafer space IC devices will shrink to atomic scale dimensions using novel, sensitive materials while at the same time being designed in a full three-dimensional configuration. In order to accommodate these trends in a technologically and economically viable way breakthroughs in metrology processes and equipment for IC device development and manufacturing are required.
However, the current industry workhorses run into physical limits. Classical optical metrology equipment does not provide an acceptable resolution at the required feature sizes, while electron-beam metrology equipment faces challenges in depth of field, true 3D information and sensitive materials. To enable the application of these disruptive semiconductor scaling technologies novel atom-scale metrology solutions at industry-level throughput are needed.
The ability to accurately measure critical dimensions at atom scale has made Atomic Force Microscopy (AFM) an important research instrument in several industrial applications including semiconductor, solar and data storage. Examples of measurement parameters are surface roughness, nano-scale channel height and width measurement and defect review in wafer and photomask. However, in most of the high-volume manufacturing applications, the target area is very large compared to the possible features of interest, and single (and hence slow) AFM has never been able to fulfill the industry needs in throughput and cost. Increasing the speed of the single AFM helps, but it still is far from the required high-volume manufacturing throughput.
Addressing this industry gap Nearfield Instruments B.V. developed a revolutionary multiple parallel, miniaturized AFM metrology system, which can measure many spots at once. Furthermore, the very high speed of each individual AFM scan head allows the user to measure those spots, each with the size of tens of micrometers, in only a few seconds. This means a significant breakthrough in AFM throughput (up to 750x of current commercial AFM systems) finally enabling AFM to complement the in-fab metrology tool set for IC device manufacturing, specifically addressing the metrology needs at the sub-10 nm device generations.