EUV Materials Research Articles

A study on the resist performance of inorganic-organic resist materials for EUV and electron-beam lithography

In the realization of further miniaturization at scales of 10 nm and below in semiconductor devices, it is essential to create new resist designs, such as hybrid inorganic-organic resist materials for ionizing radiation, in order to clarify the effect the structure of metal resist on resist performance. In this study, some hybrid inorganic-organic resist materials known as metal-oxo clusters were synthesized, and their lithographic characteristics were investigated to clarify the relationship between resist performance, such as sensitivity, resolution, and their absorption coefficient or cross section, and the density of their elements by using EUV and electron-beam (EB) exposure. Our results indicated that the sensitivity in Hf-based oxo clusters was higher than that of Ti-based and Zr-based oxo clusters in both EB and EUV exposure. Although the exposure dose was not optimized, the patterns of Ti-based, Zr-based, and Hf-based oxo clusters showed 100, 50, and 32 nm line-and-space patterns at doses of 250, 80, and 25 μC cm−2, respectively. We clarified that it is very important for new resist designs such as hybrid inorganic-organic resists to increase the photo-absorption cross section and density of elements for EUV and EB without degradation of film quality. In addition, the size and homogeneity of the building blocks and film quality are very important for the resist performance of hybrid inorganic-organic resist materials. Furthermore, it is clarified that the etch durability of metal-oxo clusters is higher than conventional resist materials, and this is much increased by annealing them at 800 °C.

Progresses and Challenges of EUV Lithography Materials

In the last years the continuous efforts on the development of EUV lithography has allowed to push the lithographic performances of the EUV photoresists on the ASML NXE:3100 full field exposure tool at imec. The latest chemically amplified photoresists can reach an ultimate resolution of 16 nm and 24 nm for line-space (L/S) and dense contacts (CH), respectively, but the major issue on EUV photoresists remains to simultaneously meet resolution, sensitivity, line-edge roughness (LER) for LS and local CD uniformity (LCDU) for CH, suggesting that the desired performance characteristics of EUV photoresists may require the development of new EUV materials. Aiming to this, imec has recently started a new project to look into novel materials for EUV lithography to explore alternative approaches that can offer superior characteristics in photoresist imaging: improved LER and line collapse, high sensitivity and high etch resistance. In this paper we report the first results from the exploration of new EUV alternative materials and the latest results from the conventional EUV photoresist evaluation and process optimization at imec towards the ASML NXE:3300 full field exposure tool.

Negative Tone Imaging Process and Materials for EUV Lithography

The advantages of NTI process in EUV is demonstrated by optical simulation method for 0.25NA and 0.33NA illumination system with view point of optical aerial image quality and photon density. The extendabLlity of NTI for h igher NA system is considered for further tight pitch and small size contact hole imaging capability. Process and material design strategy to NTI were discussed with consideration on comparison to ArF NTI process and materials, and challenges in EUV materials dedicated to NTI process were discussed as well. A new polymer was well designed for EUV-NTD process, and the resists formulated with the new polymer demonstrated good advantage of resolution and sensitivity in isolated trench imaging, and 24 nm half pitch resolution at dense C/H, with 0.3NA MET tool.

Low reflectance EUV materials: a comparative study

Get PDF Email Share Share with Facebook Tweet This Post on reddit Share with LinkedIn Add to CiteULike Add to Mendeley Add to BibSonomy Get Citation Copy Citation Text Patrick Jelinsky and Sharon Jelinsky, "Low reflectance EUV materials: a comparative study," Appl. Opt. 26, 613-615 (1987) Export Citation BibTex Endnote (RIS) HTML Plain Text Citation alert Save article