Evaluation of resist performance with EUV interference lithography for sub-22 nm patterning

The performance of EUV resists is a key factor for the cost-effective introduction of EUV lithography. Although most of the global effort concentrates on resist performance at 22 nm half-pitch, it is crucial for the future of EUVL to show its extendibility towards further technology nodes. In the last years, the EUV interference lithography tool at Paul Scherrer Institute, with its high-resolution and well-defined areal image, has been successfully employed for resist performance testing. In this paper, we present performance (dose, CD, LER) of a chemically-amplified resist for a range of 16 nm to 30 nm HP. Cross-sectional SEM images of the patterns are presented providing valuable insight into the resist's performance and failure mode. The reproducibility of our experiments are presented by repeating the same exposures with constant process conditions over the course of several months, demonstrating the excellent stability of the tool as well as the long shelf-life of our baseline resist. In addition, a comparative study of performance (dose, CD, LER) of different inorganic resists is provided. Patterns of 16 nm and 10 nm HPs are demonstrated with an EUV CAR and inorganic resists, respectively. Moreover, initial results of patterning with 6.5 nm wavelength are presented.