The lithographers have spoken. At last month's Next Generation Lithography Workshop in Colorado Springs, Colo., attending designers agreed to support continued development of a number of different next-generation lithography (NGL) technology options. This is a significant shift in thinking, which previously held that a single technology should be chosen as a standard.
NGL technologies use energy sources such as photons or charged particles to create chips. Just two years ago, the industry believed a single, universally used technology would be the best solution. Keeping everyone's resources focused in one direction seemed to be the most logical way to combat high costs. Now that optical lithography capabilities have exceeded 130 nm, though, different NGL technologies suited for different applications may be more practical.
Designers working with the various alternatives presented updates on work in their respective technologies. These included extreme ultraviolet (EUV), electron projection lithography (EPL), ion-beam projection lithography (IPL), X-ray, and multicolumn e-beam direct write. At the end of the workshop, attendees were surveyed on the pros and cons of each option. Clear leaders prevailed in each category:
- 130 nm: 193 nm optical and 248 nm optical
- 100 nm: 193 nm optical and 157 nm optical
- 70 nm: 157 nm optical, EPL, and EUV
- 50 nm: EUV and EPL
- 35 nm: EUV and EPL
According to the survey, EUV made some impressive headway in several key areas. These included defect-free, multilayer-coated ultra-low expansion blank and mask manufacturing, experimental verification of proposed solutions for wafer heating, and experimental verification of seam blending/stitching strategies. The lithographers also cited its improvements in full-field optical design, cost of ownership, reticle defect control solutions, and source and condenser optics reliability.
EPL benefitted from some recent progress, too. The survey pointed to its experimental data on beam blur and relation to CD control, experimental verification of proposed solutions for wafer heating, and experimental verification of seam blending/stitching strategies. Other aspects were spotlighted, such as its defect-free mask manufacturing at 70 nm with stress control for membrane and stencil masks, and its demonstration of real-time electron alignment capability for all levels.
For more information about NGL technology, go to International SEMATECH's web site at www.sematech.org.