Why DSA Is Cost Effective For 7nm And Below

The upcoming 7nm process node presents tough challenges both for printability and cost. At 7nm and below, multi-patterning is required, which makes the manufacturing process more expensive by requiring more masks. To control costs, any alternative technology that provides equivalent yields with fewer patterning steps should be explored. One promising option is to use directed self-assembly (... » read more

DSA Defects Continue Downward Trend

As previously discussed, the majority of defects in early directed self-assembly (DSA) processes were due to particles and other contaminants, and could be attributed to the immaturity of the process and materials. As manufacturers consider whether to incorporate DSA into specific technology nodes, they need to assure themselves that production-worthy yields can be achieved. Recent research at ... » read more

Integrating DSA

As previous articles in this series have shown, directed self-assembly may be a promising alternative for manufacturers seeking to shrink feature sizes in the face of a stalled exposure tool roadmap. It is simpler than some other frequency-multiplication techniques, can be implemented with existing equipment, and does not appear to introduce insurmountable defect issues of its own. Which does n... » read more

DSA Moves Ahead

It can be difficult to make DSA structures other than uniform arrays. One solution is to print a grating over a large area, then use a “cut” mask to eliminate the unwanted features. The challenge, though, is that aligning the cut mask to an array of tightly spaced features, such as the fins for a FinFET transistor layer, can require extremely demanding overlay specifications. While reducing... » read more

Counting And Controlling DSA Defects

If directed self-assembly is to succeed in semiconductor manufacturing, [gettech id="31046" t_name="DSA"] processes must achieve defect rates in line with the stringent requirements of sub-20nm device nodes. So far, they haven’t. However, it’s not yet clear whether the high defect rates represent a real obstacle, or are simply part of the development of any new, immature process technology... » read more

The Key To DSA

The block co-polymer most commonly used in directed self-assembly research ([gettech id="31046" t_name="DSA"]), PS-b-PMMA (poly(styrene-block-methyl methacrylate) is an excellent choice because the two component monomers have similar surface energies. The exposed top surface of the film helps to stabilize the segregated domains, making it relatively easy to achieve the lamellar line-and-space p... » read more