**2.2.2 Development parameter measurement system**

We used a development analyzer to measure development parameters. When homogeneous light is irradiated onto a resist film during development, the light waves reflected from the resist surface and light waves reflected from the wafer surface interfere, generating unique waveforms. Analyzing the waveforms of the reflected light allows us to obtain resist development rates. By varying exposure values and measuring resist development rates at different exposures, we can calculate the development parameter, among the simulation parameters [15]. This measurement has been performed before using a monitor wavelength of 470 nm. However, thin films do not generate the interference needed, and a monitor wavelength of 470 nm limits us to resist film thicknesses exceeding 100 nm. Since the film thickness of EUV resists ranges from approximately 50 to 100 nm, we developed a measurement system for our experiments based on a monitor wavelength of 265 nm (Fig.11).

Fig. 11. Resist development analyzer RDA-800EUV
