Electron beam directed repair of fused silica imprint templates

Abstract

Imprint lithography has been shown to be an effective method for replication of nanometer-scale structures from a template mold.Step-and-Flash Imprint Lithography (S-FIL™) employs a UV-photocurable imprint liquid, which enables imprint processing at ambient temperature and pressure. The use of a transparent fused silica template facilitates precise overlay. With this combination of capabilities, NIL is a multi-node technique that is suitable for advanced prototyping of processes and devices to meet the anticipated needs of the semiconductor industry. However, since the technology is 1X, it is critical to address the infrastructure associated with the fabrication of templates. An essential part of this infrastructure is the capability to identify and repair template defects. Fused silica imprint templates are typically produced from photomask substrates, and it is straightforward to make use of the tools and processes that have been developed to repair commercial photomasks. However, the optical properties of the repaired region are of secondary importance because S-FIL patterning is based on direct transfer of topography (rather than indirect transfer of an optical image). As in conventional photolithography, both additive and subtractive repairs are required to correct a variety of defect types. Repair techniques that are based on electron-beam induced chemical reactions have demonstrated the capability to perform both additive (deposition) and subtractive (etching) processes at high resolution. This work is a demonstration that electron-beam directed additive repair is capable of repairing fused silica template structures with sub-100 nm resolution.

Continuous roller nanoimprinting: next generation lithography

“…For the inspection and repair of mold defects, electron beams can be used for additive repair of a sub-hundred nm missing defect on a molten silicon mold. 166 Focused ion beam can also be used to repair the apparent defects and opaque defects of molds. 167 During the imprinting process, the mold is subjected to various forces such as tension, pressure, bending and torsion, which may cause mold deformation and failure of pattern transfer.…”

Front Matter: Volume 6521

“…For die to data base results, NGR (13) has been able to detect 20nm defects using its 2100 tool, as shown in Figure 6b. Repair of template defects can either be completed by mechanical removal of excess material (14) using a Rave 650NM tool, or by replacing missing material using a Nowatech MeRiTMG ebeam (15) enhanced deposition system. Examples of repair are shown in Figure 7.…”