We aim to develop and calibrate a set of step height standards to meet the range of steps useful for nanotechnology. Of particular interest to this community is the calibration of atomic force microscopes operating at their highest levels of magnification. In previous work we fabricated and calibrated step height standards consisting of the lattice steps on the (111) surface of single crystal Si and provided a recommended value of 312 pm ± 12 pm. In the current work we report traceable measurements of 1 nm step height specimens fabricated on the (0001) 4H-SiC surface. In this, we are seeking to fill in the range between the newly available 300 pm steps and the 8 nm steps, which are the smallest available commercially. The step height measurements were performed using a calibrated atomic force microscope (C-AFM) calibrated with respect to the wavelength of light along all three axes of motion. Analysis of the measurements yields an average step height value of 0.986 nm with a combined standard uncertainty of ± 0.015 nm, reasonably consistent with the expected value of 1.00851 nm derived from the parameters of the SiC crystal lattice.
Proceedings Title: 7638: Metrology, Inspection, and Process Control for Microlithography XXIV, Conference 7638
Conference Dates: February 22-26, 2010
Conference Location: San Jose, CA
Conference Title: SPIE Advanced Lithography Conference 2010
Pub Type: Conferences
step height, atomic force microscope, nanometrology, silicon carbide, calibration, traceability, ASTM, metrology