Process monitor of 3D-device features by using FIB and CD-SEM

Hiroki Kawada; Masami Ikota; Hideo Sakai; Shota Torikawa; Satoshi Tomimatsu; Tsuyoshi Onishi

doi:10.1117/12.2218997

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8 March 2016 Process monitor of 3D-device features by using FIB and CD-SEM

Hiroki Kawada, Masami Ikota, Hideo Sakai, Shota Torikawa, Satoshi Tomimatsu, Tsuyoshi Onishi

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Proceedings Volume 9778, Metrology, Inspection, and Process Control for Microlithography XXX; 977814 (2016) https://doi.org/10.1117/12.2218997
Event: SPIE Advanced Lithography, 2016, San Jose, California, United States

Abstract

For yield improvement of 3D-device manufacturing, metrology for the variability of individual device-features is on hot issue. Transmission Electron Microscope (TEM) can be used for monitoring the individual cross-section. However, efficiency of process monitoring is limited by the speed of measurement including preparation of lamella sample. In this work we demonstrate speedy 3D-profile measurement of individual line-features without the lamella sampling. For instance, we make a-few-micrometer-wide and 45-degree-descending slope in dense line-features by using Focused Ion Beam (FIB) tool capable of 300mm-wafer. On the descending slope, obliquely cut cross-section of the line features appears. Then, we transfer the wafer to Critical-Dimension Secondary Electron Microscope (CDSEM) to measure the oblique cross-section in normal top-down view. As the descending angle is 45 degrees, the oblique cross-section looks like a cross-section normal to the wafer surface. For every single line-features the 3D dimensions are measured. To the reference metrology of the Scanning TEM (STEM), nanometric linearity and precision are confirmed for the height and the width under the hard mask of the line features. Without cleaving wafer the 60 cells on the wafer can be measured in 3 hours, which allows us of near-line process monitor of in-wafer uniformity.

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Hiroki Kawada, Masami Ikota, Hideo Sakai, Shota Torikawa, Satoshi Tomimatsu, and Tsuyoshi Onishi "Process monitor of 3D-device features by using FIB and CD-SEM", Proc. SPIE 9778, Metrology, Inspection, and Process Control for Microlithography XXX, 977814 (8 March 2016); https://doi.org/10.1117/12.2218997

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