Characterizing the sensitivity of scatterometry

Weng Loong Foong

EECS Department
University of California, Berkeley
Technical Report No. UCB/ERL M01/14
February 2001

http://www2.eecs.berkeley.edu/Pubs/TechRpts/2001/ERL-01-14.pdf

The shrinking of device sizes has resulted in a tremendous increase in the number of transistors being patterned per unit area on a wafer. The complexity of process steps employed in manufacturing wafers today has resulted in finished wafers that are very expensive. As such, there is increasing focus and concern on the yield achievable through these manufacturing processes.

Smaller device sizes have also meant smaller device tolerances. This has put a premium on the precision of the metrology technique being employed. In order to increase yield, one must perform more measurements per wafer, which highlights the necessity of throughput. There is therefore a strong need for accurate, high-throughput in-line metrology solutions.

Scatterometry appears to be a suitable candidate. It uses broadband light for internal profiling of semiconductor device structures. Its non-destructive nature and high-throughput appear to be well-suited for integrated metrology.

This report introduces a rigorous method of characterizing the sensitivity of scatterometry for sub-100nm technology generations. Developed using a Sopra GESP5 DUV ellipsometer and based on Jones' vectors, this method can also be used to characterize the noise functions and hence the sensitivity of other ellipsometers to be used for scatterometry.

BibTeX citation:

@techreport{Foong:M01/14,
    Author = {Foong, Weng Loong},
    Title = {Characterizing the sensitivity of scatterometry},
    Institution = {EECS Department, University of California, Berkeley},
    Year = {2001},
    Month = {Feb},
    URL = {http://www2.eecs.berkeley.edu/Pubs/TechRpts/2001/9578.html},
    Number = {UCB/ERL M01/14},
    Abstract = {The shrinking of device sizes has resulted in a tremendous increase
in the number of transistors being patterned per unit area on a
wafer. The complexity of process steps employed in manufacturing
wafers today has resulted in finished wafers that are very
expensive. As such, there is increasing focus and concern on the
yield achievable through these manufacturing processes.

Smaller device sizes have also meant smaller device tolerances. This
has put a premium on the precision of the metrology technique
being employed. In order to increase yield, one must perform
more measurements per wafer, which highlights the necessity
of throughput. There is therefore a strong need for accurate,
high-throughput in-line metrology solutions.

Scatterometry appears to be a suitable candidate. It uses broadband
light for internal profiling of semiconductor device structures. Its
non-destructive nature and high-throughput appear to be well-suited
for integrated metrology.

This report introduces a rigorous method of characterizing
the sensitivity of scatterometry for sub-100nm technology
generations. Developed using a Sopra GESP5 DUV ellipsometer and based
on Jones' vectors, this method can also be used to characterize the
noise functions and hence the sensitivity of other ellipsometers
to be used for scatterometry.}
}

EndNote citation:

%0 Report
%A Foong, Weng Loong
%T Characterizing the sensitivity of scatterometry
%I EECS Department, University of California, Berkeley
%D 2001
%@ UCB/ERL M01/14
%U http://www2.eecs.berkeley.edu/Pubs/TechRpts/2001/9578.html
%F Foong:M01/14