Search

The continuos advancement of optical lithography into the regime of sub-100nm patterning capability requires the utilization of shorter exposure wavelengths such as 157nm. This in turn requires modifications in lens performance and stepper body performance. Advances in index homogeneity have made it possible to develop 157nm lens systems suitable for investigating sub-100nm lithography. Recent advances in the transmission of modified fused silica as a reticle material have made it more desirable to pursue 157nm lithography tools. MicroSteppers are a necessary vehicle to obtain photoresist and process information pertaining to the efficacy of this technology for production at the 100nm and 70nm device nodes.

We have designed, constructed, and are now performing experiments with a proof-of-concept projection electron-beam lithography system based upon the SCALPELR (scattering with angular limitation projection electron-beam lithography) principle. This initial design has enabled us to demonstrate the feasibility of not only the electron optics, but also the scattering mask and resist platform. In this paper we report on some preliminary results which indicate the lithographic potential and benefits of this technology for the production of sub-0.18 micrometer features.

A proof-of-concept experimental lithography tool, based upon the SCALPELTM principle, is currently being fabricated at AT&T Bell Laboratories. Designed from a lithographic system perspective, we feel that this experimental platform is the minimal configuration necessary to evaluate this specific printing technique, consistent with design rules from 0.18 micrometers to 0.09 micrometers . Details of the machine's electron-optics are presented, including the calculated performance of the electromagnetic lens systems. The critical lithography issues which will be examined using this tool are also discussed.© (1995) COPYRIGHT SPIE--The International Society for Optical Engineering. Downloading of the abstract is permitted for personal use only.

We have designed and constructed a proof‐of‐concept projection electron beam lithography system based on the scattering with angular limitation projection electron beam lithography principle. In this system, a thin membrane mask is used in a 4:1 reduction projection system at 100 keV. Image contrast is formed by scattering in the mask and subsequent aperturing of the scattered electrons in the back focal plane of the projection system. We have employed a step‐and‐scan architecture which uses continuously moving mask and wafer stages to trace out the full pattern. The electron beam can thus be kept small (1×1 mm in our case) which greatly simplifies the design of the electron optical system. In addition, the membrane areas can be kept small in linear dimension in one direction, minimizing in‐plane pattern distortions. Our system will be constructed in two stages. In the first stage, the mask stage is static and the wafer stage operates in step‐and‐repeat mode. This initial version of the system allows for ...