A study of hydrogen plasma-induced charging effect in EUV lithography systems

In the extreme ultraviolet lithography system, EUV-induced hydrogen plasma charging effect is observed by in situ embedded micro-detector array. The 4k-pixel on-wafer array can detect and store the distributions of H₂ plasma in each in-pixel floating gate for non-destructive off-line read. The local uniformity of H₂ plasma intensity extracted by the threshold voltages on an array and its distributions across a wafer by the average bit cell current of MDAs provide insights into the detailed conditions inside advanced EUV lithography chambers.