1 January 1988 Reliable Automatic Measurements Of Critical Dimensions Using S.E.M.
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The use of S.E.M. for Critical Dimensions is increasing with the need for measurements of less than 1 micron linewidth. This technique is so tedious that it is only acceptable if the measurements can be made in automatic mode. Therefore many difficulties appear such as charge effects which can lead to results containing a few false measurements. In the first method called Signal Recognition method the features of the extreme transitions determined in a preliminary calibration experiment are retained. To attenuate the noise and improve the speed of the treatment only a reduced number of points of the electron profile are taken into account. Thus the measurement uses a threshold zone to take into account the main points of the transition on the actual profile. The previous method must be adjusted for each new layer. Therefore another method was found which uses signal processing on the electron profile and is independent of the layers. The charges effects are attenuated by filtering the spatial frequencies and all the information contained in the edge transitions is taken into consideration. No precise settings of threshold are therefore needed In both cases these methods provide reliable measurements which allow the S.E.M. to be used as a routine metrology tool.
© (1988) COPYRIGHT Society of Photo-Optical Instrumentation Engineers (SPIE). Downloading of the abstract is permitted for personal use only.
Herve Martin, Herve Martin, Daniel Burlet, Daniel Burlet, Jean Luc Bataillon, Jean Luc Bataillon, Bruno Latombe, Bruno Latombe, } "Reliable Automatic Measurements Of Critical Dimensions Using S.E.M.", Proc. SPIE 0921, Integrated Circuit Metrology, Inspection, and Process Control II, (1 January 1988); doi: 10.1117/12.968386; https://doi.org/10.1117/12.968386


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