Recently, due to increases in the definition of high function panels for mobile devices such as smartphones and tablets,
LCD panel TFT and OLED (organic electro luminescence display) circuits are becoming increasingly denser and more
miniaturized by the year. TFT and OLED circuits are composed of several layers, such as gate, semiconductor and
contact hole (C / H). It is particularly difficult to obtain a stable resolution for C/H due to the decrease in the C/H process
margin (EL, DOF, MEEF) as a result of increases in the density of the circuit. Moreover, C/H productivity has also
markedly decreased due to an increase in the exposure dose.
In response to this, attenuated phase shift mask (Att. PSM) for large size photomasks have been proposed as a means to
improve the process margin in FPD. We have developed new PSM that can further improve the process margin and the
productivity of C/H via the effective positioning of a high transmittance phase shift film. Using a 1.5um sized hole as the
target, we confirmed the improvement effect of the optimized PSM via a software simulation and an exposure test.
Hereafter it is necessary for us to optimize the new PSM for each panel process so as to allow us to use this mask in