DocumentCode :
3175497
Title :
A new in-situ warpage measurement of a wafer with speckle -free digital image correlation (DIC) method
Author :
Yuling Niu ; Hohyung Lee ; Seungbae Park
Author_Institution :
Dept. of Mech. Eng., State Univ. of New York at Binghamton, Binghamton, NY, USA
fYear :
2015
fDate :
26-29 May 2015
Firstpage :
425
Lastpage :
431
Abstract :
During microelectronic manufacturing, a wafer undergoes many fabrication processes. Such processes include exposing a wafer to high temperature. Significant residual stresses are built up in a wafer and they are manifested as warpage of a wafer. Understanding the wafer behavior, especially warpage, during reflow process becomes one of the most important things in developing assembly process. Three Dimensional (3-D) digital image correlation (DIC), as a non-contact optical deformation measurement method, documents both in-plane and out-of plane deformation. The in-situ measurement capability allows to understand a wafer (or a wafer with multiple chips) behavior during reflow (or assembly) process. However, an object such as a monotonic surface or a mirror like wafer needs artificial speckles on the sample surface to be discernable and measured by DIC technique. To avoid contamination on wafer for surface treatment, a speckle-free 3D DIC method is proposed and its effectiveness is investigated. This method introduces an optical pattern projection method and subsequent processes in documenting topography of a wafer placed in an environmental chamber to mimic a reflow process. To validate the new method, warpage measurement result is compared with the measurement from optical profiler, a white light interferometer, and its accuracy and sensitivity are assessed quantitatively.
Keywords :
image processing; image processing equipment; integrated circuit manufacture; integrated circuit measurement; interferometers; reflow soldering; semiconductor technology; surface treatment; 3D DIC method; 3D digital image correlation; assembly process; microelectronic manufacturing; monotonic surface; noncontact optical deformation measurement method; optical pattern projection method; reflow process; surface treatment; wafer contamination; white light interferometer; Adaptive optics; Optical imaging; Optical interferometry; Optical sensors; Optical variables measurement; Pollution measurement; Surface treatment;
fLanguage :
English
Publisher :
ieee
Conference_Titel :
Electronic Components and Technology Conference (ECTC) , 2015 IEEE 65th
Conference_Location :
San Diego, CA
Type :
conf
DOI :
10.1109/ECTC.2015.7159627
Filename :
7159627
Link To Document :
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