One of the important aspects about developing, designing, and building a new processor in a fabrication plant is the metrology: the analysis of the manufacturing steps throughout the process to ensure that what you want to happen is actually what’s happening. Metrology allows the fabrication plant to identify if machines are working properly, and also help in the characterization of the end product with regards to appropriate voltage/frequency or binning through disabling silicon. If a wafer is particularly bad, it can be discarded earlier in the cycle, therefore saving money and time.
As with many other steps in the fabrication process, metrology is both time and space intensive inside a fab. As with the goal of better lithography machines moving to EUV to both enable smaller features but also speed up processing time per chip, the two main aims of metrology is accurate reporting but also throughput. Increased throughput for these machines means that fewer machines are needed for any given run, and the latency between process node steps can be shortened.
ASML has announced it has made a significant development in its multi-beam inspectional tool line. The new eScan1000 moves a single beam scanning process into a nine-beam scanning process, which ASML claims increases the throughput of such tools by up to 600% for in-line defect inspection applications. This tool is suitable for all major process nodes in current production as well as 5nm and beyond.
The company explains that the new eScan1000 tool contains an electron optics system that splits a primary beam into multiple beamlets, while also collecting and processing the results from these secondary beamlets. The tool has limited crosstalk to sub-2% to maintain imaging quality, and uses a high-speed mode to increase the overall throughput, and new computational hardware acceleration to process the data from the beamlets quicker than before. The tool is also available at a range of beam currents, assigning it for both physical defect inspection and voltage contrast inspection. ASML promotes the fact that it has a proprietary database that excels in defect detection capabilities, spotting defects missed by more traditional metrology methods.
According to the news, ASML has shipped its first eScan1000 system to a specific customer in Silicon Valley in the past week for initial testing and qualification at a customer site. It isn’t stated who the customer is.
ASML expects to expand its range of eScan1000 machines in order to meet specific customer needs, and says it will continue to develop multi-beam technology with more beams and a wider range of beam resolutions. Given the significance of this tool, we might expect to see a roadmap at a future industry event at some point later this year.