Achieving the specifications of resolution, sensitivity and line width roughness (LWR) of wafer resist is one of the top
challenges of bringing extreme ultraviolet lithography (EUVL) into high volume manufacturing. Contributions to the
resist LWR on wafer can be divided into two categories; chemical properties of the resist and aerial image. Chemical
properties of the resist are complicated and many factors contribute to LWR, such as polymer size, sensitivity, surface
reaction etc. Aerial image LWR is much simply determined by the optical properties of a mask and a scanner. Since
very small LWR value of the resist is needed, EUV mask LWR is also set very severely from ITRS .
In our previous work , we demonstrated current mask LWR as comparing them with mask resist LWR and absorber
LWR. As a result, we found that the absorber's LWR almost depends on resist patterning.
In this paper, we will present the influence of resist patterning on absorber LWR comparing resist materials and EB
tools. From the results, LWR has been reduced by 10-20% by improving EB tool. However, the LWR value at line and
space pattern for 22nm-hp case have not met target of ITRS' roadmap while, by using Non-CAR, the LWR value has
met the target. In particularly, the value at isolated line is dramatically improved using Non-CAR.