A Practical Method of Extracting the Photoresist Exposure Parameters by Using a Dose-to-Clear Swing Curve

Dill exposure {\it ABC} parameters play an important role in photolithography simulation. However, Dill parameters of chemically amplified resist are not easily determined. The case of chemically amplified resist is different from that of novolak resin photoresist, since the transmission and thickness of chemically amplified resist are not changed very much during exposure. The exact refractive index and the absorption rate of photoresist are needed in order to extract Dill parameters during exposure in an ordinary method. However, it is not easy to get these values in a device maker's research lab. We suggest an easier and simpler Dill parameter extraction method by using a dose-to-clear swing curve of the photoresist, which is easily measured in a lab. The relation between Dill parameters and dose-to-clear swing curve is studied by simulation. Dill exposure {\it ABC} parameters are obtained by matching the dose-to-clear swing curve of the experimental data with that of the simulation results. As a result of the simulation, Dill exposure {\it ABC} parameters of 193 nm chemically amplified resist are determined. In contrast to the previously presented methods, no exceptional experimental equipment or complex tools are used to get Dill exposure {\it ABC} parameters. KCI Citation Count: 1