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Weir PW - Papers on Process
Analysis & Modeling |
The most commonly reported effect of haze is a
gradual loss in transmission of the reticle that results in a
need to increase the exposure-dose in order to maintain properly
sized features. Transmission loss results in an increase in the
Across Chip Linewidth Variation that is accompanied by a
corresponding reduction in the manufacturing process window.
More significantly, even the early stages of
reticle haze result in a degradation of Best Focus, Depth of
Focus and the Exposure latitude prior to any noticeable large
area transmission loss. Production lots subject to reticle
hazing on critical layers will experience a direct loss of
lithographic yields, loss of capacity, an increase in rework
rates and an ultimate loss in overall final-test yield before
image exposure-dose increase is detected.
A sampled metrological inspection of a regular
array of points across the exposure field is therefore able to
detect any form of reticle haze if the analysis monitors the
feature-profile response rather than simply feature widths. A
model-driven method for the early detection of reticle-haze
using basic feature metrology is developed in this study.
Application results from a production reticle are used to
demonstrate validation of the technique that employs a highly
accurate method of calculation of the uniformity of the reticle
exposure-response for individual features.
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Tuned Reticle Enhancements Optimized for
Process Response
Semiconductor FabTech FT33-07 Q1 April 2007
In this study, a Process Behavior Model
methodology is presented for the analysis of feature profiles
and films to derive the relative robustness of response to
process variations for alternative feature designs. Analysis is
performed without regard to the specific mechanics of the design
itself. The design alternatives of each feature are shown to be
strong contributors not only to resolution and depth-of-focus
but also to the stability of final image response; that is the
ability of the feature profile to remain at optimum under
varying conditions of process exposure excursion.
A method of extracting the systematic component
of each feature’s design-iteration is derived providing the
ability to quantify the specific OPC response sensitivity to
changes in the exposure and process films as well as drift
introduced by the tools of the exposure set.
See Also:
http://www.Fabtech.org
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Modeled Focus Calibration & Uniformity
Weir PSFM - Software for
calibration of reticles & specialty features such as
the Phase Shift Focus Monitor
(PSFM), Z-Spin, PGM and FOCAL Structures |
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Thermal response of feature profiles
LithoWorks PEB in conjunction with Weir PW |
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2007 TEA Systems Corporation 65
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