25 March 2008 Traceable calibration of AFM step height measurements for integrated circuit manufacturing
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The growing demands of metrology have tightened the allowable tolerances of depth and step height measurements in semiconductor and nanotechnology fabrication. With manufacturing tolerances in the range of 1 nm to 3 nm, special care is required to achieve calibration traceable to the SI (Systeme International d'Unites, or International System of Units) meter in order to meet manufacturing requirements. This paper describes the steps taken to achieve this level of measurement capability. The methodology used to achieve this traceable calibration is to use an inclined plane to establish linearity over the step height range of interest of a reference critical dimension atomic force microscope (CDAFM) and then to link a single traceable step height somewhere within this range. The deviations from perfect linearity in the vertical position are shown in the paper. Then using this newly calibrated reference CD-AFM, various step height structures were used to transfer the traceable calibration from the reference CD-AFM to one-dimensional AFMs (1DAFM) used for manufacturing process control. A traceable step height calibration, with an expanded uncertainty of 2.24 nm (k = 3) is demonstrated for the reference CD-AFM. From this result, a traceable calibration of the manufacturing AFMs with a combined expanded uncertainty of 2.8 nm (k = 3) for a nominal 164 nm step height is developed.
© (2008) COPYRIGHT Society of Photo-Optical Instrumentation Engineers (SPIE). Downloading of the abstract is permitted for personal use only.
James Robert, James Robert, Bill Banke, Bill Banke, Ronald Dixson, Ronald Dixson, Carlos Strocchia-Rivera, Carlos Strocchia-Rivera, } "Traceable calibration of AFM step height measurements for integrated circuit manufacturing", Proc. SPIE 6922, Metrology, Inspection, and Process Control for Microlithography XXII, 69223V (25 March 2008); doi: 10.1117/12.778463; https://doi.org/10.1117/12.778463

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