Determining Optimal Base Dose with Electron Beam Lithography

K. Ohashi
Caltech/Pasadena City College,
United States

Keywords: electron beam lithography, photonics, microsystems, optical lithography, microfabrication, optics


Electron beam lithography (EBL) is a method in which a focused electron beam patterns the surface of a material. These patterns on the surface are known as resist, and are etched on silicon semiconductor chips. E-beam lithography is an ideal practice for the study and fabrication of materials at a nano and micro scale of volume. and are an invaluable tool for the purposes of our experiment.The objective of this research is in determining the optimal base dose for a PMMA bilayer substrate. To do so we are identifying the thickness of the substrate after both PMMA bilayers have been placed to create a point spread function (PSF) that measures the contrast of a resist material. This curve can be used in 3DPEC in BEAMER, resist model calibration in the lab, and process calibration. Acquiring these data sets will serve as an intermediate step in determining the optimal base dose through TRACER calibration.Resist thickness measurement at each dose can be determined by physical measurements such as stylus profilometer or optical measurements such as reflectometry and ellipsometry. Furthermore, after taking data on the film thickness versus exposure dose, we will input into BEAMER 3DPEC module or LAB resist calibration module where the computed contrast value is used as input into TRACER calibration section.