Images of a microlithographic sample obtained using a new near field scanning optical microscope (NSOM) that uses force regulation of the sample-tip separation are presented. The NSOM is a research instrument fitted with a metal covered glass tip probe that defines a small aperture at the sharp end. The aperture is estimated to be on the order of 100 nanometers in diameter resulting in a resolution exceeding that of diffraction limited systems. This form of microscopy can be done both in the transmission and the reflection modes. The force regulation mechanism produces a simultaneously obtained scanned force microscope (SFM) image of the topography thus permitting correlative imaging of the sample. The samples are imaged in transmission and reflection near field optical format, with white light and with coherent light. The results are compared with other forms of IC imaging and characterization, namely scanned force microscopy (SFM) and scanning electron microscopy (SEM).
Date of creation, presentation, or exhibit
Department, Program, or Center
Microelectronic Engineering (KGCOE)
Ricardo Toledo-Crow, Bruce W. Smith, Jon K. Rogers, Mehdi Vaez-Iravani, "Near-field optical microscopy characterization of IC metrology", Proc. SPIE 2196, Integrated Circuit Metrology, Inspection, and Process Control VIII, (1 May 1994); doi: 10.1117/12.174165; https://doi.org/10.1117/12.174165
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