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 Willson Research Group The University of Texas at Austin |
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Process Flow |
Exposure In most chemically
amplified photoresist systems, exposure generates acid catalyst molecules
which will react with the resist polymer in a later processing step to
change the solubility of the film in exposed regions. Several commercially
available software packages are capable of calculating the distribution of
absorbed exposure energy within the resist material. These calculations
can be performed for many different imaging schemes with arbitrary
patterns on the photomask. In our exposure simulations, we transform the
continuous distribution of energy that is calculated by this software into
discrete locations of exposure photoproducts.  In order to calculate the response of the photoactive species to exposure, the quantum efficiency of the reaction must be known. We employ pH-sensitive absorbance and fluorescence dyes to measure the amount of acid that is generated upon exposure of photoacid generator (PAG) molecules. We are currently investigating a technique in which both the PAG and the pH-sensitive dye are placed in solution. Exposure is performed using a high power UV light source (either a mercury lamp or an excimer laser) while the spectroscopic properties of the solution are monitored. Preliminary experiments confirm that this technique can be useful for rapid quantification of acid generation efficiency.  |
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Last updated September 11,
2002 |
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