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As critical dimensions (CDs) approach (lambda) /two, the use of optical proximity correction (OPC)
relies heavily on the ability of the mask vendor to resolve the OPC structures consistently. When an OPC
model is generated the reticle and wafer-processing errors are merged, quantified, and fit to a theoretical
model. The effectiveness of the OPC model depends greatly on model fit and therefore consistency in the
reticle and wafer processing. Variations in either process can 'break' the model resulting in the wrong
corrections being applied. Reticle manufacturing variables that effect OPC models are exposure tool
resolution, etch process effects, and process push (pre-bias of the fractured data). Most of the errors from
these reticle-manufacturing variables are seen during model generation, but there are some regions that are
not, and fail to be accounted for such as extremes in the line ends. Since these extreme regions of the mask
containing the OPC have a higher mask error enhancement factor (MEEF) than that of the rest of the mask,
controlling mask-induced variables is even more important. The phase shift mask (PSM) is one of the most
effective approaches to improve ArF lithography performance. MoSi or SiON dry etching technology play
an important role to fabricate phase shift masks, such as space bias type Alternating (Alt.) PSM and
chrome-less phase shift masks (CPL). The profile of the etched quartz affects the lithography performance.
In this paper we evaluate the nominal influences of the MoSi or SiON profiles on pattering and OPC by
rigorous electromagnetic field simulations. The influence of the MoSi or SiON profile is investigated by
evaluating imaginary masks. In this experiment, we simulated attenuated PSMs with tapered sidewalls,
high round and micro-trenches of varying depths. OPC modeling performances of the imaginary masks are
measured by the OPC print image CD and model fitting results. I compare the result of print image CD
with simulation. I investigate how well the OPC print image CD measurement corresponds to the
simulation. Mask CD error and sidewall angle strongly affect the OPC modeling performance. However,
micro-trench does not affect the OPC performance. This paper quantifies the effects reticle processing has
on the OPC model generation, and also mask CD variations and variable sidewall angles affect the OPC
print image CD and OPC model fitting for attenuated PSMs, micro trench depth does not play an important
role for OPC print image CD and OPC model fitting.
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