Applied Materials’ New eBeam Metrology System Paves Way to High-NA EUV Lithography

Applied Materials, Inc. introduced a new eBeam metrology system specifically designed to precisely measure the critical dimensions of semiconductor device features patterned with EUV and emerging High-NA EUV lithography.

Chipmakers use CD-SEMs (critical dimension scanning electron microscopes) to take sub-nanometer measurements of patterns once a lithography scanner transfers them from a mask to a photoresist. These measurements continuously calibrate lithography process performance to ensure the patterns are correct before they are etched into the wafer.

CD-SEMs are also used after etch to correlate intended patterns with on-wafer results. CD-SEMs thereby help control the etch process and enable a feedback loop between li-thography and etch that gives engineers highly correlated data sets for holistic process tuning.

Measuring the critical dimensions of semiconductor device features becomes more chal-lenging as photoresists get thinner with EUV and especially High-NA EUV. To capture high-resolution images that provide accurate, sub-nanometer measurements, the CD-SEM must be able to precisely apply a narrow eBeam to the small area occupied by the ex-tremely thin photoresist.

eBeam energy interacts with photoresists, and if the landing energy is too high, the resist will shrink, distorting the pattern and creating errors. Conventional CD-SEMs cannot pro-duce beams narrow enough to create high-resolution images at landing energies low enough to minimize interactions with the delicate High-NA photoresist.

Applied’s new VeritySEM 10 system features a unique architecture that enables low land-ing energy at 2X better resolution compared to conventional CD-SEMs. It also provides a 30 percent faster scan rate to further reduce interaction with the photoresist and increase throughput. The system’s industry-leading resolution and scan rate provide improved control of EUV and High-NA EUV lithography and etch processes to help chipmakers ac-celerate process development and maximize yield in high-volume manufacturing.

The VeritySEM 10 system is also being adopted by chipmakers for critical dimension me-trology applications in 3D designs, including Gate-All-Around (GAA) logic transistors and 3D NAND memories, where the system’s back-scattered electrons enable high-resolution imaging of deep structures. Among the applications for GAA chips, the VeritySEM 10 is being used to measure and characterize the selective epitaxy process which is key to tran-sistor performance. For 3D NAND memories, the system provides a large field of view and high depth of focus to measure entire staircase interconnect structures and help tune etch process recipes.

“The VeritySEM 10 system is a breakthrough in CD-SEM technology that solves the me-trology challenges of major technology inflections that will shape the industry in the years ahead,” said Keith Wells, group VP of imaging and process control at Applied Materials.