We recently imaged another t-BOC chemically amplified photoresist. Last time, the contrast between the exposed and unexposed regions were not as striking since we used the same peak at 1760 cm^-1 to image (see blog post: Latent Images of Exposed EUV Photoresist.) This one actually uses a peak that shifts by 6 cm^-1 to create a very strong contrast.

On EUV exposure of t-BOC resists, topographic differences arise between exposed and unexposed masked areas. Photo-induced Force Microscopy (PiFM) reveals that the topographic changes are accompanied by changes in IR activity. The strong signal at 1280 cm^-1 is used to identify unexposed areas while the signal at 1514 cm^-1 – unique to the exposed areas – identifies exposed areas.

PiFM Imaging of Latent EUV in t-BOC Chemically Amplified Resist

PiFM study in collaboration with G. Wallraff, M. Sanchez, H. Truong – IBM Almaden

Read more about the fascinating role played by chemically amplified resists in integrated circuits, fueling the digital age:

“Patterning the World: The Rise of Chemically Amplified Photoresists”  by David C. Brock