Fabrication issues for the prototype National Institute of Standards and Technology SRM 2090A scanning electron microscope magnification calibration standard

Abstract

Articles you may be interested inApplication of scanning probe methods for electronic and magnetic device fabrication, characterization, and testing J.A new National Institute of Standards and Technology scanning electron microscope magnification calibration standard has been fabricated and distributed in production prototype form. The SRM 2090A samples contain structures ranging in pitch from 3000 to 0.2 m and are useful at both highand low-accelerating voltages. The design and fabrication of the samples has incorporated many of the improvements suggested through two previous prototype series. This article discusses optimization of the lithographic techniques in the fabrication process. We used electron beam lithography for fabrication because of the 0.1 m features required on the samples. After liftoff, unexpected linewidth differences were measured among the smallest features. These differences were reduced through modification of the electron beam writing paths. We propose that the resist heating effect caused an axial dependence among features fabricated using the original electron beam writing paths. In addition, the susceptibility of the present prototype design to electron beam proximity effects was analyzed. Proximity effects from the 9 m range of backscattered electrons have little effect on the pitch structures of the prototype but may impact development of the prototype as a linewidth standard.

Precision improvement in diffraction measurement for the one-dimensional grating period

“…As accurate e-beam metrology system uses submicron standard references for magnification calibration, various submicron dimension references[2-8} have been investigated as a calibration standard of ebeam metrology systems; two typical reference types are pattern prototype [2,6] and grating standard. As accurate e-beam metrology system uses submicron standard references for magnification calibration, various submicron dimension references[2-8} have been investigated as a calibration standard of ebeam metrology systems; two typical reference types are pattern prototype [2,6] and grating standard.…”