Understanding the fundamental properties of photoresists used in extreme ultraviolet (EUV) photolithography is crucial, particularly regarding the complex dynamics of electron emission during EUV exposure. This knowledge is essential in semiconductor manufacturing as lithographic requirements intensify with the ongoing miniaturization of semiconductor devices. In our study, we aimed to investigate the factors influencing the yield of slow electrons emitted by EUV-exposed photoresists, focusing on how different materials with varying properties, such as electron affinity, affect this process. To achieve this, we incorporated a variety of chemical substances with similar molecular weights or chemical structures into our model photoresists to better simulate real-world conditions. We then conducted total electron yield and photoelectron spectroscopy measurements on each resist sample to assess both the intensities of total electron yield and the ratios of slow electrons (with energies below 20eV) to fast electrons emitted during EUV exposure. We revealed a trend of decreasing slow electron emission from the photoresist during EUV exposure when substances with low ionization energies or high chemical reactivity, such as onium salts, are added. This finding suggests which material properties should be targeted to decrease the electron-induced blur of the aerial image, potentially impacting the lithographic performance of EUV photoresists.
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