High-Speed Multi-Axis Nanopositioning Systems for Next-Generation CD Metrology and Lithography

There are several technology nodes on the International Technology Roadmap for Semiconduc-tors (ITRS) for which metrology and lithography tools must be developed or improved. The roadmap projects increasingly smaller feature sizes, providing the rationale for the development of next-generation lithography techniques as well as for the continuing improvement of optical lithography techniques. In addition, advanced critical-dimension (CD) metrology methods for these ever-smaller devices are needed. Both advanced lithography and precise nano-level criti-cal-dimension (CD) metrology require the ability to move accurately, rapidly, repeatedly, and precisely in X, Y, Z, and possible angular directions. Metrology in the semiconductor industry encompasses a wide variety of techniques that perform measurements on defects and dimensions. Scanned-probe (SPM)-based techniques offer a viable approach to CD metrology even in the near-future time frame. At future nodes, at sufficiently small dimensions, current approaches to wafer metrology may simply fail and there may be no solutions other than SPM-based techniques. SPM-style instruments have great capability for very precise metrology measurements, at nanolevel scales. To use SPM-based tools in metrology, ab-solute measurement and speed are essential, requiring guided motion, very accurate position sensing, high mechanical resonances, and advanced feedback systems. nPoint proposes the development of multi-axis nanopositioning systems that will enable CD me-trology and lithographic-mask metrology for upcoming technology nodes in the semiconductor device industry. These tools, based on SPM, will be routinely capable of reliable performance at sub-nanometer resolution and precision and will have increased speeds relative to present tech-nology. Within two years, nPoint expects to develop a positioning system that is both fast enough and accurate enough to form the essential component of a semiconductor wafer or ad-vanced-lithography mask CD metrology tool, enabling a technology that may ultimately, at a fu-ture node, be the only choice.