High-resolution transmission electron microscopy calibration of critical dimension (CD) reference materials

The National Institute of Standards and Technology and Sandia National Laboratories have developed a procedure for producing and calibrating critical dimension (CD), or linewidth, reference materials. These reference materials will be used to calibrate metrology instruments used in semiconductor manufacturing. The reference features, with widths down to 100 nm, are produced in monocrystalline silicon with all feature edges aligned to specific crystal planes. A two-part calibration of these linewidths is used: the primary calibration, with accuracy to within a few lattice plane thicknesses, is accomplished by counting the lattice planes across the sample as-imaged through use of high-resolution transmission electron microscopy. The secondary calibration is the high-precision electrical CD technique. In this paper, we describe the calibration procedure for these reference materials and estimate the related uncertainties.