Novel pattern trimming and shrink material (PTM (PTD) and PSM (NTI)) for ArF/EUV extension

Abstract

In recent years, as next-generation lithography, various exposure techniques have been studied such as Extreme Ultraviolet Lithography (EUVL), Directed Self Assembly (DSA) and multiple patterning processes. In particular, EUVL is the most promising candidate for the high volume manufacturing below N7 node. However, there are many problems to be solved such as materials, through put of the exposure tool and mask defect. With respect to the DSA, the fine patterning with block copolymer has been studied. But the DSA process also has the several problems such as the complicated process flow in chemo process, quality of the block copolymer and defect. On the other hand, although the multiple patterning has been applied the device manufacturing for several years, there are some problems such as significant increase in cost due to increasing of the process steps and the overlay accuracy at the multiple process steps. Therefore, Pattern Trimming Materials (PTM) and Pattern Shrink Materials (PSM) were developed for miniaturization using the current exposure technology. The PTM is applied on a resist pattern produced in a Positive Tone Development (PTD) process and trim the resist pattern. It is possible to control the trimming amount by changing the formulation and the baking process. It has been confirmed that the effectiveness of PTM is not only for the L/S pattern, but also for the 2D pattern like pillar pattern. At the same time, it is confirmed that the PTM can improve the Line Width Roughness (LWR) and Local Critical Dimension Uniformity (LCDU). On the other hand, the PSM is applied on the pattern prepared in a Negative Tone Imaging (NTI) process and then it can shrink the resist pattern after baking. We adopted the new concept for pattern shrinkage process which dramatically improved LCDU with the hole shrinkage. In this paper, we demonstrated the L/S and pillar pattern trimming by PTM and the C/H shrink by PSM with ArF immersion (ArF im) condition and EUV condition. In the future, PTM and PSM are expected to be applied in not only ArF im patterning process but also in EUVL.